CH-9-10 Sustaining Biodiversity: The Species Approach – Living in the Environment: Principles, Connections, and Solutions : Book Guide

This Document Contains Chapters 9 to 10 SUSTAINING BIODIVERSITY Chapter 9 Sustaining Biodiversity: The Species Approach Summary 1. Biologists estimate extinction rates in one of three levels. Local extinction occurs when a species in a specific area is lost but the species is still found in other places. Ecological extinction describes a species that is so small it cannot play out its ecological role where it is found. Biological extinction means that the species is gone from the earth. Scientists use measurement and models to estimate extinction rates: studying past records, identifying species-area relationships, examining lists of threatened species. Extinction rates are increasing because of human activities. Our growing population, degrading and eliminating biological environments and biological hot spots all contribute to growing extinction rates. 2. Biodiversity and species extinction are important because species provide enormous economic and ecological services we need to survive. In 100 years, mankind will destroy species that it would take five million years to rebuild. These species may provide genetic information, medicines, and information about natural processes we need to discover. These wild plants and animals are economic, recreational, and health resources. 3. Many human activities endanger wildlife, such as degradation/loss of habitat; capture of wild animals, which prevents their breeding; overfishing, oil spills, and exposure to pesticides; and extinction from nonnative species, which we introduce. 4. To prevent premature extinction of species, we must reduce threats from nonnative species; end illegal poaching and hunting; provide means for people to survive economically without killing native animals for food; maintain predator species, not destroy them; reduce greenhouse emissions and deforestation throughout the world; develop governmental policies to support biodiversity; and protect wild species in sanctuaries. Outline 9-1 What role do humans play in the extinction of species? CORE CASE STUDY: The warming trend associated with climate change is occurring twice as fast in the arctic as the rest of the world. The amount of floating sea ice is decreasing, and ice is breaking up earlier each year. As a result, polar bears are having problems storing adequate food. In 2008, the polar bear was placed on the list of threatened species by the US Fish and Wildlife Service, though the state of Alaska and oil industry leaders have fought to see this action repealed. A. Biological extinction: a species has disappeared from the earth. B. Background extinction is an historic, continuous, low level of extinction. C. Extinction rate is the percentage or number of species that go extinct each year. D. Mass extinction is the loss of many species in a short period of time. E. Extinction is natural, but there is evidence to suggest that it has accelerated as humans have populated the earth. 1. Humans have disturbed 50-80% of the earth. F. Human activities increase the pace of extinction. 1. Current rate is 100—1,000 times the background rate (0.01–.1% per year). 2. Predictions hold that this will rise to 10,000 times that background rate during this century. a. Under this scenario ¼-½ of all species will be extinct by the end of the century. 3. Extinction estimates are likely conservative. a. Rates will likely increase with the growing human population. b. Rates tend to be much higher in biodiversity hotspots. c. Habitat fragmentation limits the potential for speciation to occur. SCIENCE FOCUS: Estimating rates of extinction is problematic because extinction takes a long time, we are uncertain of how many species there are on earth, and we know little about the species that have been identified. There are several methods for estimating extinction rates, such as studying fossil records and rates of mutation, applying a species-area relationship to habitat destruction, and building mathematical models. Scientists acknowledge the shortcomings of estimates of extinction rates, but are certain that humans have caused an increase in the rate of extinction. G. Species heading toward biological extinction are either endangered or threatened. 1. Endangered species are so few in number that the species could soon become extinct. 2. Threatened/vulnerable: still abundant but likely to become endangered in the near future. a. The World Conservation Union has kept Red Lists that are the world standard for listing all threatened species throughout the world. CASE STUDY: Passenger pigeons were once one of the most numerous bird species on earth. Uncontrolled hunting and habitat loss led to their extinction by the year 1900. 9-2 Why should we care about the rising rate of species extinction? A. Biologists site four reasons we should prevent our activities from causing extinctions. 1. Species are a vital part of earth’s life support system. 2. Species support our economy (materials, medicines, ecotourism). 3. It will take millions of years for natural speciation to rebuild biodiversity. 4. Species have a right to exist, regardless of their usefulness. 9-3 How do humans accelerate species extinction? There are several causes of depletion and premature extinction of wild plants and animals. The acronym HIPPCO describes these causes. A. The loss, degradation, and fragmentation of habitat are the greatest threat to a species. 1. Deforestation in tropical forests is the greatest species eliminator followed by loss of wetlands and plowing of grasslands. 2. Island species are especially vulnerable to extinction. Many are endemic. 3. Habitat islands are isolated and surrounded by other habitats. 4. Habitat fragmentation occurs when large contiguous habitats are divided into isolated patches. B. After habitat loss, introduced species are the biggest cause of extinction. 1. The alien species can be introduced accidentally or deliberately. 2. Some of these species threaten and endanger native species. a. They have no natural predators, competitors, or pathogens in their new habitat. b. They can trigger ecological disruptions. c. There are an estimated 7,100 invasive species that have caused ecological or economic harm in the U.S. CASE STUDY: The Kudzu Vine was deliberately introduced in the 1930s to control erosion, but got out of hand. It is prolific and difficult to control, engulfing hillsides, gardens, and trees, among other things. Kudzu may eventually be used to make paper. 3. Invasive species are often introduced accidentally. a. Argentine ants aggressively attack native ant populations. 4. The best control is to prevent the nonnative species from being introduced. C. Population growth, overconsumption, pollution, and climate change. 1. Overpopulation and excessive consumption of resources eliminate habitat. 2. Pollution from chemicals like pesticides can have unintended effects on species. 3. Human activities induce rapid climate changes, increasing extinction rates. CASE STUDY: One-third of the human food supply comes from insect pollinated plants. Honeybees are responsible for 80% of that pollination. Since the 1980s there has been a decline in bee populations, but no single culprit has been found. Colony Collapse Disorder is a situation in which adult worker bees disappear from hives. There are many suspected causes, including pesticides, parasites, and microwave radiation from cell phone towers. D. Poaching—illegal killing of protected species. 1. Some protected species are killed for their valuable parts or are sold live to collectors. 2. Earns smugglers $600,000 per hour in total. 3. Low-risk, because smugglers are rarely caught and punished. E. Global legal and illegal trade in wild species for pets is a very profitable business. 1. More than 60 bird species, mostly parrots, are endangered or threatened because of the wild bird trade. 2. Amphibians, reptiles, mammals, and tropical fish are also being depleted because of pet trade. 4. Exotic plants (such as orchids and cacti) are often sold to collectors for high prices. INDIVIDUALS MATTER: Biologist Pilai Poonswad visited poachers in their villages and showed how they can make more money from hornbills through ecotourism. Now, the populations, once in serious decline, are recovering. F. Bushmeat supplies indigenous people with food and has been harvested sustainably, but as demand has gone up illegal hunting has skyrocketed. 1. Responsible for many local extinctions in West and Central Africa. 2. These hunting practices have resulted in negative ecological impacts and have driven at least one species to extinction. 3. Butchering and eating bushmeat has helped spread Ebola and AIDS from animals to humans. CASE STUDY: About 70% of the world’s bird species are declining in number, and about 12 % is threatened with extinction. The primary cause of decline is habitat loss and fragmentation. Birds are seen as indicator species, signaling environmental change in their habitats. Birds play a number of important economic and ecological roles. Their loss could trigger a cascade of extinctions. 9-4 How can we protect wild species from extinction? A. Treaties help protect endangered and threatened species, but enforcement is difficult and punishment inadequate. B. The 1975 Convention on International Trade in Endangered Species (CITES) protects 900 species from being commercially traded and restricts international trade for 29,000 species that may become threatened. 1. Enforcement is difficult and varies from country to country. 2. Many countries are not signatories and still trade in animals. 3. The Convention on Biological Diversity (CBD) binds governments to reverse the global decline in biological biodiversity. The United States has not ratified this treaty. There are no severe penalties or other enforcement mechanisms in place. C. The Endangered Species Act of 1973 (ESA) identifies and legally protects endangered species in the U.S. and abroad. 1. Identification of endangered, threatened ocean species is made by the National Marine Fisheries Service, and the U.S. Fish and Wildlife Service is responsible for identifying and listing all other endangered and threatened species. a. Biological facts form the basis of inclusion on the endangered list. b. Habitats of endangered species must be protected. 2. Efforts have been made to repeal/weaken the Endangered Species Act. 3. Conservation biologists believe that the ESA should be strengthened and modified to correct deficiencies. D. The sanctuary approach is being used to protect wild species. 1. 548 federal refuges protect wildlife but the habitats are deteriorating due to invasive species, pollutants, and little operational or maintenance funding. 2. More than three-fourths of the refuges are concentrated along major bird migration corridors. 3. About one-fifth of U.S. endangered and threatened species have habitats in the refuge system. 4. Activities considered harmful to wildlife take place in nearly 60% of wildlife refuges. E. Gene banks, botanical gardens, and farms can be used to raise threatened species and help protect species from extinction; but funding is inadequate. 1. The world’s 1600 Botanical Gardens and Arboreta contain almost one-third of the world’s known plant species, but only 3% of the world’s rare and threatened species. 2. Raising some threatened or endangered species on farms can take some of the pressure off them and perhaps offer some for commercial sale. F. Zoos and aquariums can help protect some endangered animal species as well. 1. Egg pulling collects wild eggs laid by endangered bird species and hatches them in zoos/research centers. 2. Captive breeding takes wild individuals into captivity for breeding with the commitment to reintroduce the offspring back into the wild. 3. Artificial insemination, use of surrogate mothers, use of incubators, and cross-fostering by a similar species are other ways to increase populations of rare species. 4. The ultimate goal is to reintroduce these species into the wild. 5. Reintroductions of endangered species to the wild fail because: a. There is not suitable habitat. b. Individuals bred in captivity are not able to survive in the wild. c. There is renewed overhunting/capture of the returned species. CASE STUDY: The California Condor was nearly extinct, with only 22 birds in the wild. The remaining birds were captured and bred in captivity. As of 2009, there were 348 birds in the wild. A major threat remains from lead used in ammunition. When the birds eat carcasses, lead poisoning can make them very weak. H. Precautionary Principle: When substantial preliminary evidence indicates that an activity can harm human health or the environment, we should take precautionary measures to reduce or prevent such harm. Teaching Tips Large Lecture Courses: Allow your students to explore the concept of edge effects. Either project a map of a conservation area in your region, or diagram a hypothetical one on the board. Be sure to include major contributors of edge effects, such as roads, developments, agricultural lands, etc. Invite the students to suggest ways these external factors may limit the effective size of the reserve. Focus on issues such as noise. Then question the students about what effects these might have in the reserve, especially for avian diversity. Focus on pets along the urban edge, pollutants from residential and agricultural uses, etc. Smaller Lecture Courses: Break the students into small groups. Allow them 5–10 minutes to brainstorm amongst themselves the ways in which biodiversity impacts their lives. Visit each group while they are working and encourage them to think about large processes, such as nutrient cycling and a properly functioning hydrologic cycle. Compile the lists on the board and initiate a discussion about the value of biodiversity. In light of these considerations, do humans have an obligation to protect and conserve biodiversity? Objectives 1. Describe the economic, medical, scientific, ecological, and aesthetic, recreational, and ethical significance of wild species. Define biophilia. Summarize your position toward protection of different species. 2. Describe the general process of extinction. Compare past extinctions to present extinctions. Start with E. O. Wilson's estimates for habitat destruction and loss of biodiversity. Calculate a range of estimations of biodiversity loss based on high and low assumptions. 3. Distinguish among local extinction, ecological extinction, and biological extinction. Distinguish between threatened and endangered species. List nine characteristics that make species extinction prone. 4. List three root causes of extinction of wildlife. List eight human activities that directly increase the wildlife extinction rate. Summarize the condition of the world's fisheries and the causes of those conditions. 5. Explain how bioinformatics is being used to help protect wild species. 6. State and briefly describe the most far-reaching international treaty to protect wildlife. List four strategies that have been used recently to weaken the Endangered Species Act. List three recommendations for strengthening the Endangered Species Act. State three guidelines that conservation biologists would use to determine "priority species." 7. Assess the advantages and disadvantages of using wildlife refuges, gene banks, botanical gardens, and zoos to protect wildlife. 8. Describe how wildlife populations can be managed by manipulating the successional stage of the habitat and by sport hunting. Evaluate whose interests are generally the most influential in determining wildlife management priorities. 9. Describe freshwater and marine fishery management and how it can be improved. Analyze the lessons to be learned from the decline of the whaling industry. Key Terms background extinction rate biological extinction endangered species HIPPCO precautionary principle threatened (vulnerable) species extinction rate habitat fragmentation Term Paper Research Topics 1. Significance of wildlife: medicines derived from plants and animals; commercial products from wildlife; aesthetic and recreational significance of wildlife; ecological significance of wildlife. 2. Endangered and threatened wildlife: tropical deforestation and species extinction; the international trade in endangered species and exotic pets; lead poisoning in waterfowl and the American bald eagle; Florida's alien species problem; the California condor; the Florida manatee; the blue whale; bats; rhinos; elephants. 3. Protecting wildlife: bioinformatics; gene banks; zoos and captive breeding programs; habitat management; artificial reef-building materials and methods. 4. Individuals: scientific estimation of wildlife populations and successional stages. 5. Groups: Ducks Unlimited; the National Wildlife Federation; the Audubon Society; Greenpeace; Earth First! 6. National: America's National Wildlife Refuge System. 7. Global: the World Wildlife Fund. Discussion Topics 1. Should animals be used for medical research? As sources of organs for surgical implants in humans? As sources of food, fur, fat, oils, and other commercially valuable products? Answer: Animals have been crucial for medical research, leading to significant medical advancements. However, ethical concerns arise about their welfare and the necessity of using them. Using animals for organs and commercial products also raises ethical issues regarding their treatment and exploitation. Alternatives, such as synthetic or lab-grown options, should be explored to minimize animal suffering. 2. Are extremist tactics by Greenpeace necessary or justifiable? Answer: Greenpeace’s use of extremist tactics, such as direct action and civil disobedience, aims to draw attention to urgent environmental issues. While these tactics can be effective in raising awareness, they may also alienate potential allies and lead to legal consequences. Whether they are justifiable depends on one's perspective on the balance between the urgency of environmental issues and the methods used to address them. 3. Should sport hunting be used as a wildlife management tool? Answer: Sport hunting can be a controversial tool for wildlife management. Proponents argue it can help control animal populations and fund conservation efforts. Opponents claim it can disrupt ecosystems and harm animal populations. Effective wildlife management should consider ecological balance, ethical concerns, and alternative methods. 4. Should limits be placed on genetic engineering for economic, aesthetic, ecosystem services, or other purposes? Answer: Limits on genetic engineering are necessary to address ethical, ecological, and societal concerns. While genetic engineering holds promise for advancements in health and agriculture, it also poses risks such as unintended consequences and ethical dilemmas. Regulations should balance innovation with precaution to ensure responsible use. 5. The Endangered Species Act: success or failure? Answer: The Endangered Species Act (ESA) has seen both successes and challenges. It has helped recover several species from the brink of extinction and has raised awareness about biodiversity. However, it faces criticism for its implementation and the slow recovery of some species. Overall, it is a crucial tool for conservation, though improvements are needed. 6. Should we privatize fishing rights in the United States? Answer: Privatizing fishing rights could lead to more sustainable and economically efficient management by incentivizing conservation and reducing overfishing. However, it also risks concentrating resources in the hands of a few and potentially neglecting the needs of smaller, local fishers. Careful regulation and consideration of social and ecological impacts are essential. 7. Should we lift the international ban on whaling? Answer: Lifting the international ban on whaling is highly controversial. Proponents argue it could allow regulated, sustainable whaling practices and respect cultural traditions. Opponents highlight the risk of overexploitation, threats to whale populations, and ethical concerns about hunting intelligent, endangered species. The ban remains crucial for whale conservation and ecological balance. Activities and Projects 1. Are there zoos, aquariums, botanical gardens, or arboretums in your locale operating programs designed to increase the populations of endangered species? If so, invite a spokesperson to explain one or more of these programs to your class. 2. Ask your students to bring to class and share paintings, sketches, poetry, songs, and other artistic creations depicting the beauty and wonders of wildlife. 3. Have a game warden address your class about management of populations of fish and animals that are hunted for sport. 4. Compile a list of the fish and wildlife species in your locale that have been officially designated as threatened or endangered. As a class project, find out what specific actions are being taken to assist these species. 5. As a class, examine and evaluate the goals of the World Conservation Strategy. Develop objectives that could help implement the goals that are agreed upon by the class. 6. If there are rangelands in your locale, try to schedule a class visit to examples of well- and poorly-managed grazing lands. Compare the quantity and quality of vegetation present. 7. If possible, visit projects restoring prairie lands to a more natural state. Investigate how local citizens are participating in these programs and how they are progressing. Attitudes and Values 1. Do you believe that humans have a duty to subdue wild nature to provide food and other basic needs for people and to provide jobs and income through increased economic growth? Answer: Humans have a responsibility to balance our needs with environmental sustainability. While providing food, jobs, and economic growth is essential, it should not come at the expense of ecosystems and biodiversity. Sustainable practices can meet human needs while preserving natural resources and ensuring long-term environmental health. 2. Do you believe that every living species has a right to exist, or at least struggle to exist, simply because it exists? Answer: Every species has intrinsic value and a right to exist, contributing to the planet's biodiversity and ecological balance. While not all species may survive due to natural processes, human actions should strive to minimize extinction rates and support conservation efforts to protect and sustain diverse life forms. 3. Do you believe that we have an obligation to leave Earth for future generations of humans and other species in as good a shape as we found it, if not better? Did past generations do this for you? Answer: We have a moral obligation to leave Earth in a condition that supports future generations and biodiversity. While past generations have made strides in environmental conservation, significant challenges remain. Efforts to improve and restore the environment must continue to ensure a healthier planet for future inhabitants. News Videos Planet Earth 2007; Environmental Science in the Headlines, 2007; DVD; ISBN 0495385433 Bald Eagle Soars Again: Taken Off Endangered List; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Whale Watch: In Search of the Blues; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Circle of Life; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 How Exotic Species are Devastating Hawaii’s Native Fauna; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Are We Facing an Extinction Crisis? The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Additional Video Resources Cane Toads: An Unnatural History (Documentary, 1988) A documentary detailing the spread of Hawaiian sugar-cane toads through Australia in a botched effort to introduce them as counter pests. Frontline: World, Mexico: The Business of Saving Trees (Documentary, 2008, Online) A look at how the carbon credit system has been use to create jobs in Mexico. http://www.pbs.org/frontlineworld/rough/2008/03/mexico_the_busi.html The Habitable Planet: A Systems Approach to Environmental Science (Documentary series, 2007). Videos 9 and 13. http://www.learner.org/resources/series209.html Nova—Evolution: Extinction! Main website: http://www.pbs.org/wgbh/evolution/extinction/ Teachers Guide: http://www.pbs.org/wgbh/nova/teachers/programs/0000_evoextin.html Web Resources IUCN Red List http://www.iucnredlist.org/ Red list of threatened species from around the globe. Encyclopedia of Life http://www.eol.org/ An online reference for all species named and documented on earth. Suggested Answers to End of Chapter Review Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 191. Describe how human activities threaten polar bears in the arctic. Answer: • Human activities around the globe are affecting polar bears in the arctic. As a result of climate change, there has been a reduction in the amount of floating sea ice. The ice is also breaking up earlier each year, shortening the bears’ hunting season. 2. What is biological extinction? Define background extinction rate and mass extinction. How is an extinction rate expressed? What was the background extinction rate (as a percentage)? How can the extinction of a species affect other species and ecosystem services? Describe how scientists estimate extinction rates. Give three reasons why many extinction experts believe that human activities are now causing a sixth mass extinction. Distinguish between endangered species and threatened species and give an example of each. List four characteristics that make some species especially vulnerable to extinction. Describe the extinction of the passenger pigeon in North America. Answer: • Biological extinction occurs when a species can no longer be found anywhere on the earth. • Background extinction is the loss of species on this planet as new species evolve, and occurs at most times on the earth. Mass extinctions are rare times when many species become extinct, usually caused by natural phenomena such as major climate change or large asteroids hitting the earth, which drastically alter the earth’s environmental conditions. • An extinction rate is expressed as a percent-age or number of species that go extinct within a certain time period such as a year. For example, one extinction per million species per year would be 1/ 1,000,000 0.000001 species per year. Expressed as a percentage, this is 0.000001 100, or 0.0001%— the estimated background extinction rate existing before humans came on the scene. • Species are a vital part of the earth’s life support system. They provide natural resources and natural services that keep us and other species alive. We depend on some insects for pollination of food crops and on some birds for natural pest control. Each species also has ecological value, because it plays a role in the key ecosystem functions of energy flow and chemical cycling. • One approach to estimating future extinction rates is to study records documenting the rates at which mammals and birds (the easiest to observe) have become extinct since humans evolved, and compare this with fossil records of extinctions prior to modern humans. Determining the rates at which minor DNA copying mistakes occur can also help scientists track how long various species typically last before becoming extinct. Such evidence indicates that under normal circumstances, species survive for 1 million to 10 million years before becoming extinct. Another approach is to observe how reductions in habitat size affect extinction rates. The species-area relationship suggests that, on average, a 90% loss of habitat causes the extinction of 50% of the species living in that habitat. Scientists also use mathematical models to estimate the risk of a particular species becoming endangered or extinct within a certain period of time. These population viability analysis (PVA) models include factors such as trends in population size, changes in habitat availability, interactions with other species, and genetic factors. • There is considerable evidence that humans are causing a new mass extinction as our population grows because of habitat destruction, climate change, consumption practices, and hunting. In 2005, scientists from around the world estimated that the current annual rate of species extinction is at least 100 to 1,000 times the background rate which existed before modern humans appeared some 150,000 years ago. This amounts to an extinction rate of 0.01% to 0.1% a year. Most extinction experts consider this to be a conservative estimate for several reasons. ○ The rate of species loss and the extent of biodiversity loss are likely to in-crease during the next 50– 100 years because of the projected growth of the world’s human population and resource use per person and climate change caused mostly by global warming. ○ Current and projected extinction rates are much higher than the global average in parts of the world that are highly endangered centers of biodiversity ○ We are eliminating, degrading, fragmenting, and simplifying many biologically diverse environments— such as tropical forests, tropical coral reefs, wetlands, and estuaries— that serve as potential colonization sites for the emergence of new species. This means that we may be limiting the long- term recovery of biodiversity by reducing the rate of speciation for some species. ○ The increasing fragmentation and disturbance of habitats throughout the world may increase the speciation rate for rapidly reproducing opportunist species such as weeds, rodents, and cockroaches and other insects. Thus, the real threat to biodiversity from current human activities may be long- term erosion in the earth’s variety of species and habitats. Such a loss of biodiversity would reduce the ability of life to adapt to changing conditions by creating new species. • An endangered species has so few individual survivors that the species could soon become extinct over all or most of its natural range (the area in which it is normally found). Examples include the California condor and the whooping crane. • A threatened species (also known as a vulnerable species) is still abundant in its natural range, but because of declining numbers, is likely to become endangered in the near future. Examples may change depending on the status of the species. An examples is the polar bear. • Some species also have behavioral characteristics that make them prone to extinction. The passenger pigeon and the Carolina parakeet nested in large flocks that made them easy to kill. Some types of species are more threatened with premature extinction from human activities than others are. Characteristics that make some species especially vulnerable to ecological and biological extinction include: low reproductive rate, specialized niche, narrow distribution, feed at high trophic level, fixed migratory patterns, rare, commercially valuable and large territories. • The passenger pigeon became prematurely extinct from human activities. In 1813, bird expert John James Audubon saw a single huge flock of passenger pigeons that took three days to fly over him and was so dense that it darkened the skies. By 1900, North America’s passenger pigeon, once one of the most abundant bird species on earth, had disappeared from the wild because of a combination of uncontrolled commercial hunting and habitat loss as forests were cleared to make room for farms and cities. These birds were good to eat, their feathers made good pillows, and their bones were widely used for fertilizer. They were easy to kill because they flew in gigantic flocks and nested in long, narrow, densely packed colonies. 3. What are three reasons for trying to avoid causing the premature extinction of wild species? Describe two economic and two ecological benefits of having the current variety of species. Answer: • We should prevent the premature extinction of wild species because that are a vital part of earth’s life support system, they help support our economies, and it will take millions of years for natural speciation to replace what has been lost. Additionally, some argue that species have a right to exist regardless of their usefulness to us. • Economic benefits include providing the world with food plants and ecotourism opportunities. Ecological benefits include pollination and chemical cycling. 4. What are four underlying causes of species extinction that results from human activities? What is HIPPCO? In order, what are the six largest causes of premature extinction of species resulting from human activities? What is habitat fragmentation? Describe the major effects of habitat loss and fragmentation. Why are island species especially vulnerable to extinction? Answer: • The four underlying causes include population growth, rising resource use, undervaluing natural capital, and poverty. • HIPPCO: Habitat destruction, degradation, and fragmentation; Invasive (nonnative) species; Population and resource-use growth (too many people consuming too many resources); Pollution; Climate change; and Overexploitation. • The greatest threats to any species are (in order) loss or degradation of its habitat, harmful invasive species, human population growth, pollution, climate change, and overexploitation. • Habitat fragmentation occurs when a large, intact area of habitat such as a forest or natural grassland is divided, typically by roads, logging, crop fields, and urban development, into smaller, isolated patches. • Habitat loss and fragmentation may decrease a population’s ability to survive by decreasing and altering its habitat, causing the population of a species into smaller and more isolated groups that are more vulnerable to predators, competitor species, disease, and catastrophic events such as storms and fires. It can also create barriers that limit the abilities of some species to disperse and colonize new areas, to get enough to eat, and to find mates. • Island species, many of which are endemic species, are especially vulnerable to extinction when their habitats are destroyed, degraded, or fragmented. 5. Give two examples of the benefits of introducing some nonnative species. Give two examples of the harmful effects of nonnative species that have been introduced (a) deliberately and (b) accidentally. Describe the harmful and beneficial effects of kudzu. List four ways to limit the harmful impacts of nonnative species. Describe the roles of population growth, overconsumption, pollution, and climate change in the extinction of wild species. Explain how pesticides such as DDT can be biomagnified in food chains and webs. Describe the decline of some honeybee populations in the United States, and list possible causes of the problem. What is colony collapse disorder and what might be causing it? What economic and ecological roles do honeybees play? Answer: • Some nonnative species are beneficial. Crops such as wheat and many tree plantation species are nonnative. • Deliberately introduced species that have had harmful effects include kudzu vine and the European wild boar. • Accidentally introduced species include Argentina fire ants and Burmese pythons. • Kudzu was introduced to control erosion, but becomes very difficult to control as it spreads so rapidly. • There are more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States. • Ways to limit the harmful impacts of nonnative species include: ○ Fund a massive research program to identify the major characteristics that allow species to become successful invaders and the types of ecosystems that are vulnerable to invaders. ○ Greatly increase ground surveys and satellite observations to detect and monitor species invasions and to develop better models for predicting how they will spread and what harmful effects they might have. ○ Step up inspection of imported goods and goods carried by travelers that are likely to contain invader species. ○ Identify major harmful invader species and establish international treaties banning their transfer from one country to another, as is now done for endangered species. ○ Require cargo ship handlers to discharge their ballast water and replace it with saltwater at sea before entering ports, or require them to sterilize such water or to pump nitrogen into the water to kill most invader organisms. ○ Increase research to find and introduce natural predators, parasites, bacteria, and viruses to control populations of established invaders. • Past and projected human population growth and excessive and wasteful consumption of resources have greatly expanded the human ecological footprint, which has eliminated vast areas of wildlife habitat and has caused the premature extinction of wild species. • Bioaccumulation and biomagnification. DDT is a fat-soluble chemical that can accumulate in the fatty tissues of animals. In a food chain or web, the accumulated DDT is biologically magnified in the bodies of animals at each higher trophic level. The concentration of DDT in the fatty tissues of organisms was biomagnified about 10 million times in this food chain in an estuary near Long Island Sound in the U.S. state of New York. If each phytoplankton organism takes up from the water and retains one unit of DDT, a small fish eating thousands of zooplankton (which feed on the phytoplankton) will store thousands of units of DDT in its fatty tissue. Each large fish that eats 10 of the smaller fish will ingest and store tens of thousands of units, and each bird (or human) that eats several large fish will ingest hundreds of thousands of units. • In 2006, the U.S. National Academy of Sciences reported a 30% drop in U.S. honeybee populations since the 1980s. Possible causes include pesticide exposure, parasitic mites, invasion by Africanized honeybees, new viruses, and poor nutrition as a result of declining biodiversity. • Colony collapse disorder in the phenomenon in which most or all of the adult worker bees mysteriously disappear from their hives. Suspected causes of CCD include parasites, a fungus, viruses, bacteria, pesticides, and poor nutrition resulting in stress caused when commercial bee colonies are fed an artificial diet while being trucked around the country and rented out for pollination. • Globally, about one-third of the human food supply comes from insect-pollinated plants, and honeybees are responsible for 80% of that pollination. Additionally, honeybees provide for the pollination of flowering plants. 6. Describe the poaching of wild species and give three examples of species that are threatened by this illegal activity. Why are tigers likely to disappear within a few decades? Describe how Pilai Poonswad helped to protect rare rhinoceros hornbills in Thailand. Describe the threat to some forms of wildlife from increased hunting for bush meat. Answer: • Some protected species are illegally killed (poached) for their valuable parts or are sold live to collectors. Globally, this illegal trade in wildlife brings in an average of at least $1.1 million an hour. Organized crime has moved into illegal wildlife smuggling because of the huge profits involved—surpassed only by the illegal international trade in drugs and weapons. Few of the smugglers are caught or punished and at least two-thirds of all live animals smuggled around the world die in transit. To poachers, a live mountain gorilla is worth $150,000, a giant panda pelt $100,000, a chimpanzee $50,000, an Imperial Amazon macaw $30,000, and a Komodo dragon reptile from Indonesia $30,000. A poached rhinoceros horn can be worth as much as $55,000 per kilogram ($25,000 per pound). It is used to make dagger handles in the Middle East and as a fever reducer and alleged aphrodisiac in China and other parts of Asia. In 1900, an estimated 100,000 tigers roamed free in the world. • Despite international protection, only about 3,500 tigers remain in the wild, on a rapidly shrinking range, according to a 2006 study by the World Conservation Union. Today, all six tiger subspecies are endangered in the wild and roam across only about 7% of their natural range. The Bengal or Indian tiger is at risk because a coat made from its fur can sell for as much as $100,000 in Tokyo. With the body parts of a single tiger worth as much as $25,000—and because few of the poachers are caught or punished—it is not surprising that illegal hunting has skyrocketed. According to a 2006 study by tiger experts, without emergency action to curtail poaching and preserve their habitat, few if any tigers will be left in the wild within 20 years. • Pilai Poonswad visited poachers directly and showed that they could make more money via ecotourism if they protected the hornbills than they can through killing them. • Hunting for bush meat threatens gorilla, orangutan, chimpanzee, elephant, and hippopotamus populations due to habitat loss and hunting. 7. Describe the major threats to bird species in the world and in the United States. List three reasons why we should be alarmed by the decline of bird species. Describe the relationship between vultures, wild hogs, and rabies in India. Answer: • Bird species are threatened with extinction, mostly because of habitat loss, degradation, and fragmentation. • Reasons for concern include: ○ Birds are excellent environmental indicators because they live in every climate and biome, respond quickly to environmental changes in their habitats, and are relatively easy to track and count. ○ Birds perform a number of important economic and ecological services in ecosystems throughout the world. ○ Birds help control populations of rodents and insects (which decimate many tree species), remove dead animal carcasses (a food source for some birds), and spread plants throughout their habitats by helping with pollination and by consuming and excreting plant seeds. • As vultures died off because of poisoning, the increase in carcasses led to increases in populations of wild dogs. As the dogs’ population grew, so did the number of dogs with rabies. 8. Describe two international treaties that are used to help protect species. Summarize the history of the U.S. Endangered Species Act. How successful it has been, and why is it controversial? Answer: • The 1975 Convention on International Trade in Endangered Species (CITES) is signed by 174 countries and bans hunting, capturing, and selling of threatened or endangered species. It lists some 900 species that cannot be commercially traded as live specimens or wildlife products because they are in danger of extinction. The Convention on Biological Diversity (CBD), ratified by 190 countries (but as of 2009, not by the United States), legally commits participating governments to reversing the global decline of biodiversity and to equitably sharing the benefits from use of the world’s genetic resources. This includes efforts to prevent or control the spread of ecologically harmful invasive species. • The U. S. Endangered Species Act of 1973 (ESA; amended in 1982, 1985, and 1988) was designed to identify and protect endangered species in the United States and abroad. This act is probably the most far-reaching environmental law ever adopted by any nation, which has made it controversial. Under the ESA, the National Marine Fisheries Service (NMFS) is responsible for identifying and listing endangered and threatened ocean species, while the U.S. Fish and Wildlife Services (USFWS) is to identify and list all other endangered and threatened species. Any decision by either agency to add a species to, or remove one from, the list must be based on biological factors alone, without consideration of economic or political factors. However, economic factors can be used in deciding whether and how to protect endangered habitat and in developing recovery plans for listed species. The ESA also forbids federal agencies (except the Defense Department) to carry out, fund, or authorize projects that would jeopardize an endangered or threatened species or destroy or modify its critical habitat. For offenses committed on private lands, fines as high as $100,000 and one year in prison can be imposed to ensure protection of the habitats of endangered species, although this provision has rarely been used. This part of the act has been controversial because at least 90% of the listed species live totally or partially on private land. The ESA also makes it illegal for Americans to sell or buy any product made from an endangered or threatened species or to hunt, kill, collect, or injure such species in the United States. Between 1973 and 2009, the number of U.S. species on the official endangered and threatened species lists increased from 92 to 1,318. According to a 2000 study by the Nature Conservancy, one-third of the country’s species are at risk of extinction, and 15% of all species are at high risk—far more than the 1,318 species on the endangered and threatened species lists. 9. Describe the roles and limitations of wildlife refuges, gene banks, botanical gardens, wildlife farms, zoos, and aquariums in protecting some species. Describe efforts to protect the California condor from extinction. What is the precautionary principle and how can we use it to help protect wild species and overall biodiversity? What are three important issues related to the use of this principle? Answer: • Zoos, aquariums, game parks, and animal research centers are being used to preserve some individuals of critically endangered animal species, with the long-term goal of reintroducing the species into protected wild habitats. These institutions typically suffer from lack of funding and inadequate space. Additionally, if the goal is reintroduction to the wild, this may fail because of habitat destruction, overhunting or poaching. • The population of California n condors was reduced to just 22 birds remaining in the wild. To help save this highly endangered species, scientists captured the remaining birds and bred them in captivity at zoos for eventual return to the wild. As of 2009, there were 348 living condors. About 180 of them live in the wild throughout the southwestern United States and the rest live in zoos and bird sanctuaries. • The precautionary principle: When substantial preliminary evidence indicates that an activity can harm human health or the environment, we should take precautionary measures to prevent or reduce such harm even if some of the cause-and-effect relationships have not been fully established scientifically. This principle should be invoked in protecting biodiversity, as we do not know what the overall ramification of species loss will be on other species, ecosystems or the human population. • The issues related to this principle are: ○ The allocation of limited resources ○ Deciding which species should get the most attention ○ Determining which habitats are most critical to protect 10. What are this chapter’s three big ideas? Describe how the three principles of sustainability are related to protecting the polar bear and other wild species from extinction and to protecting the earth’s overall biodiversity. Answer: • The three big ideas are: ○ We are greatly increasing the extinction of wild species by destroying and degrading their habitats, introducing harmful invasive species, and increasing human population growth, pollution, climate change, and overexploitation. ○ We should avoid causing the extinction of wild species because of the ecological and economic services they provide and because their existence should not depend primarily on their usefulness to us. ○ We can work to prevent the extinction of species and to protect overall biodiversity by using laws and treaties, protecting wildlife sanctuaries, and making greater use of the precautionary principle. • Protection of biodiversity is the epitome of one of the core principles. In addition, species cycle nutrients within ecosystems. The entire functioning of ecosystems is driven by solar power. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. What are three aspects of your lifestyle that might directly or indirectly contribute to the endangerment of the polar bear (Core Case Study)? Answer: Student answer sill vary, but will most likely revolve around the issue of excessive energy consumption, both directly (as in driving, heating the house, etc.) and indirectly (in terms of the energy intensive items we consume). Three aspects of lifestyle that might contribute to the endangerment of polar bears are: 1. Carbon Footprint: High energy consumption and reliance on fossil fuels contribute to climate change, which melts sea ice, crucial for polar bears' hunting and breeding. 2. Consumer Choices: Purchasing products linked to deforestation or unsustainable practices can exacerbate environmental changes that affect polar bear habitats. 3. Travel Habits: Frequent long-distance travel by air or car increases greenhouse gas emissions, further impacting global warming and polar bear habitats. 2. Describe your gut-level reaction to the following statement: “Eventually, all species become extinct. So it does not really matter that the passenger pigeon is extinct or than the polar bear (Core Case Study) or the world’s remaining tiger species are endangered mostly because of human activities.” Be honest about your reaction, and give arguments to support your position. Answer: The possibility exists that at some point in the future species that currently exist on the earth may become extinct. This is part of the evolutionary process and we have much evidence for this from fossil records. However, a main concern today is that humans are accelerating some species toward extinction, or have already brought about their extinction at rates that far exceed the rate that occurs within the natural process. We may be bringing about the extinction of species that otherwise, left to their own devices, may not become extinct in the short term. Who knows how long the passenger pigeon would have existed in the natural world if it had not been subject to human-induced effects that brought about its demise? The horseshoe crab has essentially remained unchanged for over 200 million years, long before humans inhabited the earth, but since around 1990 the number of horseshoe crabs has declined worldwide by around 50% due to the effect of humans, for example, using them for bait in certain fishing industries. 3. Do you accept the ethical position that each species has the inherent right to survive without human interference, regardless of whether it serves any useful purpose for humans? Explain. Would you extend this right to the Anopheles mosquito, which transmits malaria, to infectious bacteria, and to individual tigers that have killed people? Explain. Answer: Yes, every species that does exist has a right to exist without human interference. Humans have let themselves become apart from nature and feel that they have the right to become the masters over it. As such, we look at species only as being beneficial or detrimental to humans. This right to exist should be extended to any creature, whether it be a disease-causing vector such as the mosquito, a virus or bacterium, or an animal that sometimes attacks and kills humans that have ventured into, or encroached upon, its natural habitat. There are only a few sample vials of smallpox left in the world. An ethical debate exists as to whether these vials should be destroyed. They have a right to exist like any other organism on earth. We have eradicated the disease but who are we to decide to consciously bring about an organisms total eradication? 4. Wildlife ecologist and environmental philosopher Aldo Leopold wrote this with respect to preventing extinction of wild species: “To keep every cog and wheel is the first precaution of intelligent tinkering.” Explain how this statement relates to the material in this chapter. Answer: Aldo Leopold was speaking of the interrelatedness of species and the functionality of an intact ecosystem. Loss of biodiversity can have unforeseen effects, which may ultimately break down the functionality of ecosystems. Humans, as a species, are dependent upon the proper functioning of ecosystems. Should species loss disrupt important processes such as nutrient or water cycling, the implications for humanity could be drastic. Additionally, we have little knowledge of the genetic diversity of species or their medicinal properties, and these aspects could prove very important to humanity in the future. 5. What would you do if fire ants invaded your yard and house? Explain your reasoning behind your course of action. How might your reasoning affect other species or the ecosystem you are dealing with? Answer: This would be an excellent time to get to know something about the ecology of fire ants. Most people’s first impulse would be to eradicate them in some way. The first consideration should be why they are invading. Perhaps there is something that could be altered to make your habitat less suitable to them. Next, careful attention should be given to their eradication, as it might simply open the door for another species’ population to grow. 6. Which of the following statements best describes your feelings toward wildlife? (a) As long as it stays in its space, wildlife is okay. (b) As long as I do not need its space, wildlife is okay. (c) I have the right to use wildlife habitat to meet my own needs. (d) When you have seen one redwood tree, elephant, or some other form of wildlife, you have seen them all, so lock up a few of each species in a zoo or wildlife park and do not worry about protecting the rest. (e) Wildlife should be protected in its current ranges. Answer: (e) Wildlife should be protected. My view lies somewhere between the stewardship worldview and the environmental wisdom worldview. We can manage forests sustainably and produce products that have been made using best management practices, but we should not allow wild species to suffer any harmful effects of our actions. 7. Environmental groups in a heavily forested state want to restrict logging in some areas to save the habitat of an endangered squirrel. Timber company officials argue that the well-being of one type of squirrel is not as important as the well-being of the many families who will be affected if the restriction causes the company to lay off hundreds of workers. If you had the power to decide this issue, what would you do and why? Describe any trade-offs included in your solution Answer: We need to focus on saving whole ecosystems and not just focus on one particular species. We need to educate everyone about all of the species that live in the wooded area and maybe use the location for ecological education. The area could be assessed to determine where the population of squirrels is the smallest and maybe allow some selective cutting in that region only. 8. Write an argument for (a) preserving a weed species in your yard, and for (b) not exterminating a colony of wood-damaging carpenter ants in your home. Answer: (a) This answer will largely be dependent upon the extent to which the weed is truly invasive. Is it non-native? Is it causing harm to its new environment? Is its population expending? These considerations will determine the approach. (b) This argument may have to revolve around the fact that the homeowner has provided a tremendous food resource to a population and now must suffer the consequences of that population’s inevitable growth. 9. Congratulations! You are in charge of preventing the extinction, caused by human activities, of a large share of the world’s existing species. List the three most important policies you would implement to accomplish this goal? Answer: First, take measures to reduce population growth, as this is the root cause of many environmental problems. Second, strictly enforce wildlife protection laws locally, nationally, and globally. Third, educate the public about the benefits of protecting species. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: 1. How can individual lifestyle changes significantly impact polar bear conservation efforts? 2. What are the most effective strategies for mitigating climate change to protect polar bear habitats? Data Analysis Question Examine these data released by the World Resources Institute and answer the following questions: Country Total Land Area in square kilometers (square miles) Protected Area as per cent of total land area (2003) Total number of Known Breeding Bird Species (1992-2002) Number of Threatened Breeding Bird Species (2002) Threatened Breeding Bird Species as per cent of Total Number of Known Breeding Bird Species China 9,599,445 (3,705,386) 7.8 218 74 India 3,288,570 (1,269,388) 5.2 458 72 United States 9,633,915 (3,718,691) 15.8 508 55 Afghanistan 647,668 (250,000) 0.3 181 11 Cambodia 181,088 (69,900) 23.7 183 19 Costa Rica 51,114 (19,730) 23.4 279 13 Haiti 27,756 (10,714) 0.3 62 14 Rwanda 26,344 (10,169) 7.7 200 9 Source of data: http://earthtrends.wri.org/country_profiles/index.php?theme=7 World Resources Institute, Earth Trends, Biodiversity and Protected Areas, Country Profiles 1. For each of the eight countries, complete the table by filling in the last column. 2. Arrange the countries from largest to smallest according to Total Land Area. Does there appear to be any correlation between the size of country and the percentage of Threatened Breeding Bird Species? Explain your reasoning. 1. Answer: Country Total Land Area in square kilometers (square miles) Protected Area as per cent of total land area (2003) Total number of Known Breeding Bird Species (1992-2002) Number of Threatened Breeding Bird Species (2002) Threatened Breeding Bird Species as per cent of Total Number of Known Breeding Bird Species China 9,599,445 (3,705,386) 7.8 218 74 India 3,288,570 (1,269,388) 5.2 458 72 United States 9,633,915 (3,718,691) 15.8 508 55 Afghanistan 647,668 (250,000) 0.3 181 11 Cambodia 181,088 (69,900) 23.7 183 19 Costa Rica 51,114 (19,730) 23.4 279 13 Haiti 27,756 (10,714) 0.3 62 14 Rwanda 26,344 (10,169) 7.7 200 9 Source of data: http://earthtrends.wri.org/country_profiles/index.php?theme=7 World Resources Institute, Earth Trends, Biodiversity and Protected Areas, Country Profiles 2. Answer: Country Total Land Area in square kilometers (square miles) Threatened Breeding Bird Species as per cent of Total Number of Known Species Rwanda 26,344 (10,169) 4.5 Haiti 27,756 (10,714) 22 Costa Rica 51,114 (19,730) 4.7 Cambodia 181,088 (69,900) 10 Afghanistan 647,668 (250,000) 6.0 India 3,288,570 (1,269,388) 16 United States 9,633,915 (3,718,691) 11 China 9,599,445 (3,705,386) 34 Aside from the smallest country (Rwanda) in this sample having the lowest percentage of Threatened Breeding Bird Species and the largest country (China) having the highest percentage, there appears to be no correlation, since the values in between fluctuate widely. Chapter 10 Sustaining Terrestrial Biodiversity: The Ecosystem Approach Summary 1. Conservation biology attempts to slow down the rate at which we are destroying and degrading the earth’s biodiversity through the use of rapid response strategies. Hot spots, the most endangered and species-rich ecosystems, receive emergency action to slow down/stop the loss of biodiversity in these systems. Bioinformatics manages, analyzes, and communicates basic biological and ecological information to help sustain biodiversity. 2. Forests provide important ecological and economic services, are storehouses of biodiversity, and affect weather and climate throughout the world. Forest resource management varies according to the type of forests. In diverse forests, the age and size of trees are preserved to foster natural regeneration. Government policies will primarily determine the future of forests, including old-growth forests. 3. Forests in the United States should be managed so as to retain as much of the forests as possible. Clear-cutting and seed-tree cutting methods of harvesting are scourges on the forest; selective cutting is the most reasonable way to harvest trees. 4. Deforestation is one of the most serious ecological problems of this century. The earth’s forests have been reduced by 20–50% and the destruction continues to this day. Deforestation has many harmful environmental effects: reduces ecological services of forests, releases large amounts of carbon dioxide in the air, produces a drier and hotter climate; reduces the control of water movements, and increases soil erosion. 5. Tropical deforestation is one of the biggest threats to world economic health and climate. To help sustain tropical forests, nations of the world must unite to discourage deforestation and degradation. 6. Problems affecting parks run from little/no protection from their governments or being too small to sustain large animal species, to being too popular and, therefore, overused by people. Some methods for managing parks include: limiting the number of visitors, raising entry fees to provide funds for maintenance and management, managing parks in reference to nearby federal lands, discouraging development around already established parks, and providing more volunteers and better paid employees to maintain the parks. 7. Only about 7% of the world’s terrestrial areas are protected from potentially harmful human activities; these areas need to be expanded throughout the world. In order to adequately conserve biodiversity, at least 20% of the earth’s land area should be protected in a global network of reserves. 8. Wilderness is an amount of land legally set aside to prevent/minimize harm from human activities. This is land where human beings may visit but not remain. Wilderness areas are important for: (1) their natural beauty, (2) their natural biological diversity, (3) their enhancement of mental and physical health of visitors, and (4) their contributions to biodiversity and to evolutionary possibilities. 9. Ecological restoration is the process of repairing damage caused by humans to the biodiversity and dynamics of natural ecosystems. 10. Initiatives that would help to sustain the earth’s biodiversity include: – Immediately preserving the world’s biological hot spots – Protecting the remaining old-growth forests – Mapping the world’s terrestrial and aquatic biodiversity – Identifying and taking action for the world’s marine hot spots, just as for the terrestrial hot spots – Protecting and restoring the world’s lakes and river systems – Developing a global conservation strategy that protects the earth’s terrestrial and aquatic ecosystems – Making conservation profitable – Initiating ecological restoration projects worldwide Key Questions and Concepts 10-1 What are the major threats to forest ecosystems? CORE CASE STUDY: In 1977 Wangari Maathai founded the Green Belt Movement, which is a women’s self-help group directed at planting and protecting trees across rural Kenya. The movement has grown to 50,000 member and 6,000 tree nurseries. Maathai was awarded the Nobel Peace Prize for her efforts in 2004. A. Forests occupy about 30% of the earth’s surface, excluding Greenland and Antarctica. B. Forests are classified according to their age and structure into two major types. 1. Old growth/frontier forests are those that have not been seriously disturbed by human activities/natural disasters for hundreds of years. These forests are storehouses of biodiversity because of the ecological niches they provide for wildlife species. 2. Second-growth forests develop in an area after human activities or natural forces have removed them. i. Tree plantations/tree farms replant and clear-cut one species of trees in a regular cycle. C. 60% of all forests are second growth, 36% are primary forest, and 4% are tree plantations. D. Forests provide valuable ecological and economic services. 1. Forests provide habitat for about 2/3 of all terrestrial species. E. The presence of logging roads has many negative consequences. 1. Logging roads increase erosion and sediment runoff, fragment habitats, and contribute to loss of biological diversity. 2. They expose forest to invasion by nonnative pests, diseases, and wildlife species. F. Different harvesting methods affect the continuing growth of forests. 1. In selective cutting, intermediate-aged/mature trees are cut singly or in small groups. 2. Clear-cutting removes every single tree in one cutting. 3. Strip cutting removes a strip of trees along the contour of the land and spreads the cutting out over several decades. SCIENCE FOCUS: Researchers have attempted to devise a method to place a monetary value on ecosystem services. They hope that these efforts will make people aware that: ecosystem services are essential for humans and their economies, the economic value of ecosystem processes is substantial, and sustainably managed ecosystems are a long-term source of income. G. Different types of fires affect forest ecosystems. 1. Surface fires usually burn underbrush, leaf litter, and small seedlings, but most wild animals survive. They have benefits such as burning flammable ground material to prevent more destructive fires and release nutrients, stimulate germination of some seeds, and control pathogens and insects. 2. Crown fires are extremely hot and leap from treetop to treetop. Buildup of ground litter increases likelihood of crown fires that result in greater destruction and soil erosion. H. Accidental and deliberate introductions of forest diseases and insects are a major threat to forests. I. Climate change threatens many forests. 1. Some species are sensitive to heat. J. Deforestation is widespread across the planet and is continuing. 1. World Resources Institute surveys indicate that original forest cover has decreased by about 46%. 2. Global deforestation is occurring by at least 0.2–0.5% per year, with most losses taking place in developing countries. 3. If conditions don’t change within the next 10–20 years, 40% of the world’s remaining forests will have been logged or converted to other uses. CASE STUDY: Forests cover about 30% of the land area in the United States. Early in the nation’s history, forests were decimated. Today, however, forests cover more land area in the U.S. than they did in 1920. Much of this is second growth. On the other hand, much of the nation’s old-growth forest has been replaced with simplified tree plantations. K. Tropical forests make up 6% of the earth’s land area. 1. They once covered twice as much area. Most destruction has occurred since 1950. 2. At least half of the world’s terrestrial plant and animal species are found in tropical rainforests. L. Four primary causes of tropical forest destruction are: 1. Population growth and poverty drive subsistence farmers to tropical forests where they attempt to farm. 2. Government subsidies make tropical forest resources cheap—relative to their full ecological value. 3. Degradation begins when roads are cut into the forest for logging. Selective cutting removes the best timber (high grade). 4. Healthy rain forests do not burn, but logging, settlements, grazing, and farming have fragmented the forest; they dry out, making them more flammable. 5. Burning contributes to global climate change, accounting for 17% of the annual greenhouse gas emissions. 10-2 How should we manage and sustain forests? A. Fire management can be improved. 1. The Smokey Bear educational campaign taught that fire is bad. Ecologists suggest that putting out all fires increases the risk of a catastrophic fire event. 2. According to the Forest Service, severe fire could threaten 40% of federal forest lands due to fuel buildup. 3. Risk can be reduced via prescribed fire, allowing natural fires to burn, clearing vegetation from around structures, and manual thinning in fire prone areas. . SCIENCE FOCUS: Scientific Certification Systems (SCS) is part of the Forest Stewardship Council (FSC), which certifies timber and products generated from environmentally sound and sustainable practices. Still, as of 2009, only 5% of the world’s forested area is certified. B. Improving the efficiency of wood use would reduce pressure to harvest trees on public and private land. 1. Up to 60% of wood consumed in the U.S. is wasted due to inefficient use of construction materials, excess packaging and overuse of junk mail, inadequate paper recycling, and failure to reuse wooden shipping containers. C. Use of tree-free fibers for papermaking is another way to reduce pressure on tree harvest. 1. Use of fibers from agricultural residues and crops such as kenaf are alternatives to tree fibers. CASE STUDY: About half the wood harvested each year in the U.S., and three-fourths of that in developing countries, is used for fuel. Rings of deforested land surround cities, and the demand for fuelwood in urban areas exceeds the sustainable yield of nearby forests. Community forestry projects involve local people in planting small plantations of fast-growing fuelwood trees in community wood lots. People can use more efficient, less polluting woodstoves, solar ovens, or electric hotplates powered by wind power to reduce the demand for fuelwood. D. In order to reduce deforestation and degradation of tropical forests: 1. We must help settlers learn methods to practice in small-scale sustainable agriculture and forestry. 2. We must harvest sustainable fruits and nuts in the rain forests. 3. We should consider using debt-for-nature swaps, which allow countries that owe foreign aid/foreign debt to act as custodians of protected forest reserves in order for debt to be forgiven. 4. We can allow corporations and countries that emit a lot of carbon dioxide to pay tropical countries to protect their forests. 5. Initiate replanting programs. 6. We can reduce our demand for products that encourage unsustainable resource extraction. 10-3 How should we manage and sustain grasslands? A. Grasslands provide many important ecological services yet are the second-most altered ecosystem. B. Livestock often overgraze on rangelands (non-managed grasslands) and pastures (managed grasslands), causing soil and erosion and exploitation by invasive plants. CASE STUDY: Grasslands are partially maintained by occasional wildfires. Ranchers in the Malpai Borderlands have overgrazed and suppressed fires for more than a century. Now, ranchers and environmentalists have joined forces to restore native grasses and animal species to this area.. C. To utilize grasslands in a sustainable way, we must control the number and distribution of livestock. D. Ranchers, ecologist, and environmentalists in the United States are working together to protect grasslands by rotating livestock. E. Invasive plants can be combated with herbicides, mechanical removal, and controlled burning. CASE STUDY: Since 1980, there has been a population surge in the ranch country in the Southwestern United States. This has led to uncontrolled urban development. Now, ranchers and environmentalists are working together to conserve ranchland as a means of sustaining the remaining grassland habitats. One strategy is to pay ranchers for conservation easements, which bar future owners from developing land. 10-4 How should we manage and sustain parks and nature reserves? A. There are more than 1,100 national parks in more than 120 countries. 1. Parks in developing countries possess the greatest biodiversity, but are least protected. CASE STUDY: The U.S. National Park system includes 58 major national parks. Their popularity brings pollution and associated problems with overuse. Non-native species threaten biodiversity in parks, which are often isolated amidst development. Inadequate budgets add to the challenges faced by our national parks. SCIENCE FOCUS: Scientists are monitoring the gray wolves that have been reintroduced to Yellowstone National Park. The effects of this reintroduction have been many. They are impacting the populations and behaviors of large grazing animals. This has helped to restore riparian zones that were degraded by elk. Coyote populations have also been decreased. It will take decades of research to understand the way these animals impact the functioning of their ecosystem. B. Conservation biologists call for strict protection of at least 20% of earth’s global system as biodiversity reserves that include multiple examples of all the earth’s biomes. C. Large reserves are usually the best way to protect biodiversity, but in some locales several well-placed, medium-sized, isolated reserves may be a better way to protect a variety of habitats. 1. Buffer zones establish an inner zone of intact habitat. 2. The United Nations has established 553 biosphere reserves globally, based on this principle. D. Establishment of habitat corridors helps to support more species and allows migration of vertebrates with large ranges. 1. Migration of individuals can occur when environmental conditions deteriorate within a range. 2. They can also threaten isolated populations by allowing movement of pest species, disease, fire, and exotic species between reserves. 3. They may be costly to acquire, protect, and maintain. CASE STUDY: The most impressive country for conserving its land and natural resources has been Costa Rica. It has established a system of reserves and national parks, and it devotes a larger portion of its land to biodiversity conservation than any other country. It has consolidated its parks and reserves into eight mega reserves, which help generate a $1 billion per year in ecotourism industry. Costa Rica once had one of the highest rates of deforestation and now has one of the lowest. E. The wilderness concept provides for large tracts of undeveloped land. CASE STUDY: The Wilderness Act was not passed in the U.S. until 1964. Only about 4.7% of U.S. land is protected as wilderness, with almost three-fourths of it in Alaska. Only about 1.8% of the lower 48 states are protected as wilderness. Only 81 of the 233 distinct ecosystems are protected in wilderness. However, in 2009, the US government granted wilderness protection to 2 million acres of public land. 10-5 What is the ecosystem approach to sustaining biodiversity? A. We should focus on protecting ecosystems and their biodiversity rather than distinct species. 1. Map and inventory ecosystems. 2. Identify the most endangered ecosystems. 3. Restore degraded ecosystems. 4. Make development biodiversity-friendly via tax breaks. B. Biodiversity hotspots are areas especially rich in species, and in great risk of extinction. 1. In all 34 hotspots, a total of 86% of habitat has been destroyed. C. Another approach to biodiversity conservation is to protect those areas where vital ecosystem processes are being impaired. D. Life-raft ecosystems are those in which people live in extreme poverty and must degrade ecosystem processes to survive. E. Environmental degradation can be partially reversed through ecological restoration. F. Scientists study how natural systems recover and are learning to speed up repair operations by the following approaches: 1. Restoration returns a degraded habitat to a condition as close to its natural state as possible. 2. Rehabilitation involves trying to restore an ecosystem to a functional state rather than is original state. 3. Replacement is replacing a degraded ecosystem with a productive pasture or tree farm. 4. Creating artificial ecosystems is another possibility. SCIENCE FOCUS: Guanacaste National Park in Costa Rica is the site of one of the world’s largest ecological restoration projects. The project involves local community members in the restoration effort. Many local students have been trained in restoration ecology. This project is guided by the belief that it will ultimately fail unless the local communities see some economic benefit in its success. G. Reconciliation Ecology involves inventing, establishing, and maintaining new habitats for species to coexist with humans. CASE STUDY: The Blackfoot River comprises a large and diverse watershed. It is also home to many people who witnessed environmental degradation due to poor mining, logging, and grazing practices. This stimulated activism at the community level. In 1993, community members organized the Blackfoot Challenge. This resulted in drastic improvements, and became a classic example of reconciliation ecology. Teaching Tips Large Lecture Courses: After covering the major causes of tropical deforestation, ask the students to generate ideas about how they might be contributing to deforestation. What activities are we involved with that might lead to deforestation in tropical regions? Next, explore the ethics of the situation. Does the group feel that we should avoid this outcome, if possible? In what ways might we alter out behaviors to limit our income on tropical biodiversity? Smaller Lecture Courses: Divide the class in half and have one group generate a list of benefits of ecotourism, while the other brainstorms a list of the cons associated with this economic pursuit. After they have generated a substantial list of ideas, stimulate a debate about the two sides. What factors about a place or a society make it a good or bad practice? Should we always support ecotourism as a means to sustainable economic development? Key Terms Biodiversity hotspots commercial forest ecological restoration old-growth forests overgrazing pastures rangelands reconciliation ecology second-growth forests tree plantation (farm) under grazing wilderness Term Paper Research Topics 1. Multiple-use and moderate-use public lands in the United States: Bureau of Land Management policies and programs in the arid West. 2. U.S. restricted-use lands: the National Parks System; the National Wilderness System. 3. Wilderness preservation in developing countries. 4. Groups: the Nature Conservancy; the Wilderness Society; reducing the pressure of people on the national parks; Everglades restoration; lobbying; environmental legislation; environmental regulations; environmental research; environmental communications. 5. National laws: the Alaskan Land-Use Bill; the Endangered American Wilderness Act of 1978; the Wild and Scenic Rivers Act of 1968; the 1974 and 1976 Forest Reserves Management Acts. 6. International environmental movement: the Green Movement; environmental groups of the emerging Eastern European countries; the Chipko movement; the Montreal Protocol; the Earth Summit at Rio de Janeiro in 1992. 7. Global: the UN World Heritage Trust; debt-for-nature swaps; solar cookers and the world firewood crisis. Discussion Topics 1. Alaska's value: wilderness or oil supply? Answer: Alaska's value encompasses both its vast wilderness and its potential oil resources. The wilderness provides critical habitats, biodiversity, and ecological services, while oil resources contribute to economic development. Balancing conservation with responsible resource extraction is essential to preserve natural beauty and support economic needs. 2. Should fires be allowed to burn in forests on public lands? Answer: Allowing natural fires to burn in forests can be beneficial for ecosystem health, promoting biodiversity and nutrient cycling. However, controlled burns and fire management strategies are necessary to prevent uncontrolled wildfires that could threaten human settlements and infrastructure. A balanced approach to fire management is crucial for maintaining forest health and safety. 3. Should mining be allowed in national wildlife refuges? Answer: Mining in national wildlife refuges can pose significant risks to ecosystems, wildlife habitats, and water resources. While mineral extraction can provide economic benefits, it often conflicts with conservation goals. Prioritizing the protection of these sensitive areas is essential to preserve their ecological value and ensure long-term sustainability. 4. Should parts of wilderness areas be set aside for wildlife only? Answer: Designating parts of wilderness areas solely for wildlife can help protect critical habitats and support biodiversity. These areas can serve as refuges from human disturbance, allowing ecosystems to function naturally. Balancing wildlife protection with recreational and resource-use needs is key to effective conservation and management. Activities and Projects 1. Invite a conservation biologist to speak to your class. Ask about his or her work and to distinguish it from the work of wildlife managers. 2. Invite a National Park Service or state official to your class to discuss park problems and future management plans. 3. Arrange a field trip to a wilderness area. Collect works of art, music, and literature that reflect human feelings toward the wilderness. Hold a class discussion about the value of wilderness areas. 4. As a class project, poll the students at your school on the subject of environmental protection and its importance. Investigate their beliefs and opinions regarding a variety of environmental quality management issues and alternatives. Research the development of environmental law in the United States. Describe the relationship of humans to nature that has guided different legislation. 5. If there are state or national forests in your locale, try to schedule a class visit to examples of well- and poorly-managed forests. Compare the quantity and quality of vegetation present. Attitudes and Values 1. Have you ever visited rangeland? How did you feel about the land? What benefits do you enjoy as a result of cattle grazing? Answer: Visiting rangeland offers an appreciation for its expansive, open landscapes and the role it plays in ranching. While cattle grazing can support local economies and maintain open spaces, it also requires careful management to avoid overgrazing and environmental degradation. Benefits include access to beef products and the maintenance of traditional ranching practices. 2. Have you ever visited a national park? How did you feel about the park? Were there any problems at the park? Do you believe in protecting the park for the future? Answer: National parks often provide a sense of awe and connection to nature. However, they can face issues such as overcrowding, environmental damage, and insufficient funding. Protecting national parks for future generations is crucial to preserving their natural beauty, biodiversity, and recreational opportunities. 3. Have you ever visited a wilderness area? How did you feel about the wilderness? What benefits do you enjoy as a result of protection of wilderness areas? Answer: Wilderness areas offer a profound sense of solitude and unspoiled nature. They provide essential ecosystem services, such as clean air and water, and serve as refuges for wildlife. The protection of these areas helps maintain biodiversity and allows for natural processes to occur without human interference. 4. Would you support classifying a much larger portion of the public lands (such as parks, forests, and rangeland) in your country as wilderness and making such land unavailable for timber cutting, livestock grazing, mining, hunting, fishing, motorized vehicles, or any type of human structure? Answer: Supporting the classification of more public lands as wilderness can enhance conservation efforts and protect ecosystems from exploitation. While it may limit certain economic activities, the long-term benefits of preserving natural habitats and biodiversity often outweigh the immediate economic gains. This approach can ensure that future generations inherit a healthier and more resilient environment. News Videos Planet Earth 2007; Environmental Science in the Headlines, 2007; DVD; ISBN 0495385433 Circle of Life; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Darwin’s Galapagos Under Threat; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Additional Video Resources The Habitable Planet: A Systems Approach to Environmental Science (Documentary series, 2007). Videos 4 and 9. http://www.learner.org/resources/series209.html The Lorax (Animated, Dr. Seuss, 1972, Online) Animated version of the classic book about an industrialist and the destruction of the environment. Main Website: http://video.google.com/videoplay?docid=6650219631867189375 Activity: http://www.teacherweb.com/TN/WestValleyMiddle/TheLorax/ NOVA—Fire Wars Main Website: http://www.pbs.org/wgbh/nova/fire/ Teacher’s Guide: http://www.pbs.org/wgbh/nova/teachers/programs/2908_fire.html Major World Ecosystems; (Documentary, 2004) Covers a variety of ecosystems, and what their requirements are. http://www.amazon.com/Major-World-Ecosystems/dp/B00004T01Y Valley at the Crossroads (Documentary, 2002) The battle over sprawl in California's Central Valley, where 50% of America's fruits, and vegetables are grown. http://www.bullfrogfilms.com/catalog/vac.html Livable Landscapes. (Documentary, 2002) How growth and sprawl affect the quality of life in New England, and some possible solutions. http://www.bullfrogfilms.com/catalog/ll.html Web Resources National Interagency Fire Center http://www.nifc.gov/fire_info/nfn.htm Has up-to-date information on wildfires as well as educational materials. Suggested Responses to Critical Thinking Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 218. Describe the Green Belt Movement founded by Wangari Maathai (Core Case Study). Answer: • Wangari Maathai started with a small tree nursery in her backyard in 1977 and eventually founded the Green Belt Movement, which continues today. The main goal of this women’s self-help group is to organize poor women in rural Kenya to plant and protect millions of trees in order to combat deforestation and provide fuel wood. Since 1977, the 50,000 members of this grassroots group have established 6,000 village nurseries and planted and protected more than 40 million trees. 2. Distinguish among an old-growth forest, a second- growth forest, and a tree plantation (tree farm or commercial forest). What major ecological and economic benefits do forests provide? Describe the efforts of scientists and economists to put a price tag on the major ecological services provided by forests and other ecosystems. Answer: • An old-growth forest is an uncut or regenerated primary forest that has not been seriously disturbed by human activities or natural disasters for several hundred years or more. Old-growth forests are reservoirs of biodiversity because they provide ecological niches for a multitude of wildlife species. • A second-growth forest is a stand of trees resulting from secondary ecological succession. These forests develop after the trees in an area have been removed by human activities such as clear-cutting for timber or cropland or by natural forces such as fire, hurricanes, or volcanic eruption. • A tree plantation, also called a tree farm or commercial forest, is a managed tract with uniformly aged trees of one or two genetically uniform species that usually are harvested by clear-cutting as soon as they become commercially valuable. The land is then replanted and clear-cut again in a regular cycle. • Forests provide major ecological and economic services. Ecological services include: support energy flow and chemical cycling, reduce soil erosion, absorb and release water, purify water and air, influence local and regional climate, store atmospheric carbon, and provide numerous wildlife habitats. Economical services include fuel wood, lumber, pulp to make paper, mining, livestock grazing, and recreation jobs. • See SCIENCE FOCUS: Putting a Price Tag on Nature’s Ecological Services. In 1997, a team of ecologists, economists, and geographers estimated the monetary worth of the earth’s ecological services and the biological income they provide. They estimated the latter to be at least $ 33.2 trillion per year. According to this study, the world’s forests provide us with ecological services worth at least $ 4.7 trillion per year— hundreds of times more than their economic value. 3. Describe the harm caused by building roads into previously inaccessible forests. Distinguish among selective cutting, clear-cutting, and strip cutting in the harvesting of trees. What are the major advantages and disadvantages of clear- cutting forests? What are two types of forest fires? What are some ecological benefits of occasional surface fires? What are four ways to reduce the harmful impacts of diseases and insects on forests? What effects might projected climate change have on forests? Answer: • New highways degrade natural capital. Building roads into previously inaccessible forests is the first step to providing timber, but it also paves the way to fragmentation, destruction, and degradation of forest ecosystems, due to increased erosion and sediment runoff into waterways, habitat fragmentation, and loss of biodiversity. Logging roads also expose forests to invasion by nonnative pests, diseases, and wildlife species. And they open once-inaccessible forests to miners, ranchers, farmers, hunters, and off-road vehicle users. • Harvesting Trees: ○ Selective cutting occurs when intermediate-aged or mature trees in an uneven-aged forest are cut singly or in small groups. ○ Clear-cutting occurs when loggers remove all the trees from an area. ○ Strip cutting involves clear-cutting a strip of trees along the contour of the land within a corridor narrow enough to allow natural regeneration within a few years. After regeneration, loggers cut another strip next to the first, and so on. . • Advantages of clear- cutting forests include: higher timber yields, maximum profits in shortest time, can reforest with fast- growing trees and good for tree species needing full or moderate sunlight. Disadvantages include: reduces biodiversity, destroys and fragments wildlife habitats, increases water pollution, flooding, and erosion on steep slopes and eliminates most recreational value. • Two types of fires can affect forest ecosystems. Surface fires usually burn only undergrowth and leaf litter on the forest floor. They may kill seedlings and small trees, but they spare most mature trees and allow most wild animals to escape. Another type of fire, called a crown fire, is an extremely hot fire that leaps from treetop to treetop, burning whole trees. Crown fires usually occur in forests that have not experienced surface fires for several decades, a situation that allows dead wood, leaves, and other flammable ground litter to accumulate. These rapidly burning fires can destroy most vegetation, kill wildlife, increase soil erosion, and burn or damage human structures in their paths. • Occasional surface fires have a number of ecological benefits. They burn away flammable ground material and help to prevent more destructive fires. They also free valuable mineral nutrients tied up in slowly decomposing litter and undergrowth; release seeds from the cones of lodgepole pines; stimulate the germination of certain tree seeds, such as those of the giant sequoia and jack pine; and help to control tree diseases and insects. Wildlife species such as deer, moose, muskrat, and quail depend on occasional surface fires to maintain their habitats and provide food in the form of vegetation that sprouts after fires. • There are several ways to reduce the harmful impacts of tree diseases and insect pests on forests. One is to ban imported timber that might introduce harmful new diseases or insects; another is to remove or clear-cut infected and infested trees. We can also develop tree species that are genetically resistant to common tree diseases. Another approach is to control insect pests by applying conventional pesticides. Scientists also use biological control (bugs that eat harmful bugs) combined with very small amounts of conventional pesticides. • Rising temperatures and increased drought from projected climate change will likely make many forest areas more suitable for insect pests, which would then multiply and kill more trees. The resulting combination of drier forests and more dead trees could increase the incidence and intensity of forest fires. This would add more of the greenhouse gas CO2 to the atmosphere, which would further increase atmospheric temperatures and cause even more forest fires, in a spiraling cycle of increasingly harmful changes. 4. What is deforestation and what parts of the world are experiencing the greatest forest losses? List some major harmful environmental effects of deforestation. Describe the encouraging news about deforestation in the United States. How serious is tropical deforestation. What are the major underlying and direct causes of tropical deforestation? Answer: • Deforestation is the temporary or permanent removal of large expanses of forest for agriculture, settlements, or other uses. These losses are concentrated in less-developed countries, especially those in the tropical areas of Latin America, Indonesia, and Africa. • Harmful effects of deforestation include ○ Decreased soil fertility from erosion. ○ Runoff of eroded soil into aquatic systems. ○ Premature extinction of species with specialized niches. ○ Loss of habitat for native species and migratory species such as birds and butterflies. ○ Regional climate change from extensive clearing. ○ Release of CO2 into atmosphere. ○ Acceleration of flooding. • Forests in the United States (including tree plantations) cover more area than they did in 1920. The primary reason is that many of the old-growth forests that were cleared or partially cleared between 1620 and 1920 have grown back naturally through secondary ecological succession. • Tropical rainforests are experiencing great forest losses. • Underlying causes include pressures from population growth and poverty. Together they push subsistence farmers and the landless poor into tropical forests, where they try to grow enough food to survive. Direct causes include logging and ranching. 5. Describe four ways to manage forests more sustainably. What is certified timber? What are four ways to reduce the harms to forests and to people from forest fires? What is prescribed fire? What are three ways to reduce the need to harvest trees? Describe the fuel wood crisis and list three ways to reduce its severity. What are five ways to protect tropical forests and use them more sustainably? Answer: • See Solutions: Sustainable Forestry for more ideas: ○ Identify and protect forest areas high in biodiversity. ○ Rely more on selective cutting and strip cutting. ○ No clear-cutting on steep slopes. ○ No logging of old-growth forests. • See Science Focus: Certifying Sustainably Grown Timber for more information: Since 1993, Scientific Certification Systems (SCS) has evaluated the company’s timber production. SCS, which is part of the nonprofit Forest Stewardship Council (FSC), was formed to develop a list of environmentally sound practices for use in certifying timber and products made from such timber. • Four strategies for reducing fire-related harm to forests and people: ○ Set small, contained surface fires, such as prescribed fires, to remove flammable small trees and underbrush in the highest-risk forest areas. ○ Allow many fires on public lands to burn, thereby removing flammable underbrush and smaller trees, as long as the fires do not threaten human structures and life. ○ Protect houses and other buildings in fire-prone areas by thinning a zone of about 60 meters (200 feet) around them and eliminating the use of flammable materials such as wooden roofs. ○ Thin forest areas vulnerable to fire by clearing away small fire-prone trees and underbrush under careful environmental controls. • Prescribed fires are small, contained surface fires intended to remove flammable small trees and underbrush in the highest-risk forest areas. • Three ways to reduce the need to harvest trees include reducing wood waste, using alternative sources, and embracing sustainable practices. • Fuel wood and charcoal made from wood are used for heating and cooking by more than 2 billion people in developing countries. By 2050, the demand for fuel wood could easily be 50% greater than the amount that can be sustainably supplied. • One way to reduce the severity of the fuel wood crisis is to establish small plantations of fast- growing fuel wood trees and shrubs around farms and in community woodlots. Another approach is to burn wood more efficiently by providing villagers with cheap, more fuel-efficient, and less- polluting wood stoves, household biogas units that run on methane produced from crop and animal wastes, solar ovens, and electric hotplates powered by solar- or wind- generated electricity. In addition, villagers can switch to burning the renewable sun- dried roots of various gourds and squash plants. • Ways to protect tropical forests and use them more sustainably include: protect the most diverse and endangered areas, educate settlers about sustainable agriculture and forestry, subsidize only sustainable forest use, protect forests with debt-for-nature swaps and conservation concessions, certify sustainably grown timber, reduce poverty, and slow population growth. 6. Distinguish between rangelands and pastures. What is overgrazing and what are its harmful effects? Describe efforts to reduce overgrazing in the Malpai Borderlands. What are three ways to reduce overgrazing and use rangelands more sustainably? Describe the conflict among ranching, biodiversity protection, and urban development in the American West. Answer: • Rangelands are unfenced grasslands in temperate and tropical climates that supply forage, or vegetation, for grazing (grass-eating) and browsing (shrub-eating) animals. Pastures are managed grasslands or enclosed meadows usually planted with domesticated grasses or other forage. • Overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of a rangeland area. It reduces grass cover, exposes the soil to erosion by water and wind, and compacts the soil (which diminishes its capacity to hold water). Overgrazing also enhances invasion by species such as sagebrush, mesquite, cactus, and cheatgrass, which cattle will not eat. • Since 1993, ranchers, scientists, environmentalists, and government agencies have joined forces to restore the native grasses and animal species to the Malpai Borderlands after nearly a century of overgrazing. • Reduce overgrazing by fencing off these areas, which eventually leads to its natural ecological restoration by ecological succession; move cattle around by providing supplemental feed at selected sites and by strategically locating water holes and tanks and salt blocks; and suppress the growth of unwanted invader plants by use of herbicides, mechanical removal, or controlled burning. • For decades, scientists have fought to reduce overgrazing and to preserve the natural landscape. As a result, the preserved scenery has led to a development boom directed at people who value the region for its natural beauty. Now, as a result of this development, ranchers, ecologists, and environmentalists are joining together to help preserve cattle ranches in order to sustain the key remaining grasslands and the habitats they provide for native species. 7. What major environmental threats affect national parks in the world and in the United States? How could national parks in the United States be used more sustainably? Describe some of the ecological effects of reintroducing the gray wolf to Yellowstone National Park in the United States. What percentage of the world’s land has been set aside and protected as nature reserves, and what percentage do conservation biologists believe should be protected? Answer: • National parks are threatened because they are too small and fragmented to sustain many large animal species, because of invasions by nonnative species that compete with and reduce the populations of native species, and lack of funding. Around the world, there are also many problems with lack of protection and people entering parks to harvest resources. • Parks could be more sustainable with decreased degradation of the habitat and resources, protection from illegal logging and poaching, and consolidation of green areas. • The return of the gray wolf, a keystone predator species, has sent ecological ripples through the park’s ecosystem. With wolves around, elk populations have declined. Remains of elk killed by wolves provide an important food source for grizzly bears and other scavengers such as bald eagles and ravens. And wary elk are gathering less near streams and rivers, which has helped to spur the regrowth of aspen, cottonwoods, and willow trees in those areas. This in turn has helped to stabilize and shade stream banks, which has lowered the water temperature and made better habitat for trout. Beavers seeking willow and aspen have returned. And the dams they build establish wetlands and create more favorable habitat for aspens. The wolves have also cut in half the population of coyotes—the top predators in the absence of wolves. This has reduced coyote attacks on cattle in surrounding ranches and has increased populations of smaller animals such as ground squirrels and mice, hunted by coyotes. • Currently, only 12% of the earth’s land area is protected strictly or partially in nature reserves, parks, wildlife refuges, wilderness, and other areas. This 12% figure is misleading because no more than 5% of the earth’s land is strictly protected from potentially harmful human activities. Conservation scientists call for full protection of at least 20% of the earth’s land area in a global system of biodiversity reserves, which would include multiple examples of all the earth’s biomes. 8. How should nature reserves be designed and connected? Describe what Costa Rica has done to establish nature reserves. What is wilderness and why is it important? Describe the controversy over protecting wilderness in the United States. Describe a four-point strategy for protecting ecosystems. What is a biodiversity hotspot and why is it important to protect such areas? Why is it also important to protect areas where deteriorating ecosystem services threaten people and other forms of life? Answer: • Conservation biologists call for using the buffer zone concept to design and manage nature reserves. This means protecting an inner core of a reserve by usually establishing two buffer zones in which local people can extract resources sustainably without harming the inner core. Instead of shutting people out of the protected areas and likely creating enemies, this approach enlists local people as partners in protecting a reserve from unsustainable uses such as illegal logging and poaching. • Costa Rica has consolidated its parks and reserves into eight zoned mega reserves, designed to sustain about 80% of the country’s rich biodiversity. Green areas are protected reserves and yellow areas are nearby buffer zones, which can be used for sustainable forms of forestry, agriculture, hydropower, hunting, and other human activities. • One way to protect undeveloped lands from human exploitation is by legally setting them aside as large areas of undeveloped land called wilderness. There are two important reasons for protecting wilderness and other areas from exploitation and degradation, both involving long-term needs. One is to preserve biodiversity as a vital part of the earth’s natural capital. The other reason is to protect wilderness areas as centers for evolution. • Some critics oppose protecting large areas for their scenic and recreational value or a relatively small number of people. They believe this keeps some areas of the planet from being economically useful to people here today. • The four-point strategy involves: ○ Mapping the world’s terrestrial ecosystems and creating an inventory of species ○ Locating and protecting the most endangered ecosystems and species ○ Seeking to restore as many degraded ecosystems as possible ○ Making development biodiversity-friendly by providing significant financial incentives and technical help to private landowners who agree to help protect endangered ecosystems. • Biodiversity hotspots are areas especially rich in plant species that are found nowhere else and are in great danger of extinction. These areas need to be protected because suffer serious ecological disruption, mostly because of rapid human population growth and the resulting pressure on natural resources. • One to help sustain the earth’s biodiversity and its people is to identify and protect areas where vital ecosystem are being impaired enough to reduce biodiversity or harm local residents. Proponents of this approach contend that we must identify highly stressed life raft ecosystems. In such areas, people live in severe poverty, and a large part of the economy depends on various ecosystem services that are being degraded severely enough to threaten the well- being of people and other forms of life. I 9. What is ecological restoration? Describe a science-based, four-point strategy for carrying out ecological restoration and rehabilitation? Describe the ecological restoration of a tropical dry forest in Costa Rica. Define and give three examples of reconciliation ecology. Describe the Blackfoot Challenge reconciliation ecology project. Answer: • Ecological restoration is the process of repairing damage caused by humans to the biodiversity and dynamics of natural ecosystems. • Science-based, four-point strategy for carrying out ecological restoration and rehabilitation: ○ Identify the causes of the degradation (such as pollution, farming, overgrazing, mining, or invasive species). ○ Stop the abuse by eliminating or sharply reducing these factors. This would include removing toxic soil pollutants, improving depleted soil by adding nutrients and new topsoil, preventing fires, and controlling or eliminating disruptive nonnative species. ○ If necessary, reintroduce species—especially pioneer, keystone, and foundation species—to help restore natural ecological processes, as was done with wolves in the Yellowstone ecosystem. ○ Protect the area from further degradation and allow secondary ecological succession to occur. • See Science Focus: Ecological Restoration of a Tropical Dry Forest in Costa Rica. Costa Rica is the site of one of the world’s largest ecological restoration projects. In the lowlands of its Guanacaste National Park, a small tropical dry forest was burned, de-graded, and fragmented by large- scale conversion to cattle ranches and farms. Now it is being restored and relinked to the rain forest on adjacent mountain slopes. The goal is to eliminate damaging nonnative grasses and re-establish a tropical dry forest ecosystem over the next 100– 300 years. • A new form of conservation biology, called reconciliation ecology focuses on inventing, establishing, and maintaining new habitats to conserve species diversity in places where people live, work, or play. • Examples of reconciliation ecology include ○ Protecting local wildlife and ecosystems that provide economic resources for their communities by encouraging sustainable forms of ecotourism. In the Central American country of Belize, conservation biologist Robert Horwich has helped to establish a local sanctuary for the black howler monkey. ○ Protecting vital insect pollinators, such as native butterflies and bees, which are vulnerable to insecticides and habitat loss. Neighbors work together in planting gardens of flowering plants as a source of food for pollinating insect species. And neighborhoods and farmers build devices using wood and plastic straws, which serve as hives for increasingly threatened pollinating bees. ○ Protecting bluebirds within human- dominated habitats where most of the bluebirds’ nesting trees have been cut and the bluebird populations have declined. Special boxes were designed to accommodate nesting bluebirds, and the North American Bluebird Society has encouraged Canadians and Americans to use these boxes on their properties and to keep house cats away from nesting bluebirds. Now bluebird numbers are growing again. ○ In Berlin, Germany, people have planted gardens on many large rooftops. These gardens support a variety of wild species by containing varying depths and types of soil and exposures to sunlight. Such roofs also save energy by providing insulation and absorbing less heat than conventional rooftops do, thereby helping to keep cities cooler. ○ In the U. S. state of California, San Francisco’s Golden Gate Park is a large oasis of gardens and trees in the midst of a major city. It is a good example of reconciliation ecology, because it was designed and planted by people who transformed it from a system of sand dunes. • In response to their recognition that their local environment was being degraded, the people of the Blackfoot River Valley began meeting and taking a grassroots approach to revitalizing their local environment. The results were dramatic. Blackfoot Challenge members have restored and enhanced large areas of wetlands, streams, and native grasslands. They have reserved large areas of private land under conservation easements. 10. What are four ways in which we can all help sustain the earth’s terrestrial biodiversity? What are this chapter’s three big ideas? Describe the relationship between preserving biodiversity as it is done by the Green Belt Movement and the three scientific principles of sustainability. Answer: • Four ways that we can all help sustain biodiversity include adopting a forest, planting trees and taking care of them, recycling paper and buying recycled paper products, buying sustainably produced wood and wood products • This chapters big ideas are: ○ The economic values of the important ecological services provided by the world’s ecosystems are far greater than the value of raw materials obtained from those systems. ○ We can manage forests, grasslands, parks, and nature preserves more effectively by protecting more land, preventing over-use of these areas, and using renewable resources provided by them no faster than such resources can be replenished by natural processes. ○ We can sustain terrestrial biodiversity by protecting severely threatened areas, protecting remaining undisturbed areas, restoring damaged ecosystems, and sharing with other species much of the land we dominate. • The preservation of biodiversity as exemplified by the greenbelt movement relates to the principles of sustainability, as it involves valuing and sustaining biodiversity, enhancing the capture of solar energy and the conversion of that energy into something useful for people, and it involves reforesting regions so that they can sequester carbon, an important component of resource cycling. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. Describe the ecological, economic, and social benefits of the Green Belt Movement (Core Case Study). Is there an area near where you live that could benefit from such intensive planting of trees? If so, describe how it would benefit the area. Answer: The Green Belt Movement has helped to control erosion and provide for the livelihood of many of the region’s poor. It also provides empowerment for many women in this area. 2. If we fail to protect a much larger percentage of the world’s remaining old-growth forests and tropical rainforests, describe three harmful effects that this is likely to have on any children and grandchildren you might have. Answer: Children would grow up in a much less diverse world. Children would have to do without whatever potential medicines or other new products would be discovered from a comprehensive look our biodiversity, and that would perhaps suffer the ecological consequences of seeing rainfall and weather patterns change as a result of losing these ecosystems. 3. In the early 1990’s, Miguel Sanchez, a subsistence farmer from Costa Rica, was offered $600,000 by a hotel developer for a piece of land that he and his family had been using sustainably for many years. The land contained an old-growth rain forest and a black sand beach within an area under rapid development. Sanchez refused the offer. What would you have done if you were in Miguel Sanchez’s position? Explain your decision. Answer: Money can compromise our best intentions. Ultimately, one has to consider what the surrounding area will be like. How intense will the edge effects be, once this region is developed? Will the habitat that is being conserved actually be valuable in the future? 4. There is controversy over whether Yellowstone National Park in the United States should be accessible by snowmobile during winter. Conservationists and backpackers, who use cross-country skis or snowshoes for excursions in the park during winter, say no. They contend that snowmobiles are noisy, pollute the air, and can destroy vegetation and disrupt some of the park’s wildlife. Proponents say that snowmobiles should be allowed so that snowmobilers can enjoy the park during winter when cars are mostly banned. They point out that new snowmobiles are made to cut pollution and noise. A proposed compromise plan would allow no more than 950 of these new machines into the park per day, only on roads, and primarily on guided tours. What is your view on this issue? Explain. Answer: Snowmobile access should not be allowed during the winter months in Yellowstone. Even new environmentally-friendly, pollution-free snowmobiles will destroy vegetation and disrupt wildlife. During this normally peaceful time during the year, the park should remain closed to motorized traffic in order for the ecosystem to function without disruption for the season. 5. In 2009, environmental analyst Lester R. Brown estimated that reforesting the earth and restoring the earth’s degraded rangelands would cost about $15 billion a year. Suppose the United States, as the world’s most affluent country, agreed to put up half this money, at an average annual cost of $25 per American. Would you support doing this? Explain. What other part or parts of the federal budget would you decrease to come up with these funds? Answer: Yes, I would support this. The United States comprises less than 5 percent of the world’s population but we are responsible for a much higher percentage use of the world’s resources and resulting environmental degradation. Other countries should also kick in and help offset the costs. These funds could come out of the military budget that the Pentagon receives. 6. Should developed countries provide most of the money to help preserve remaining tropical forests in developing countries? Explain. Answer: Yes, developing countries need help from the developed world in order to preserve their remaining tropical forests. Many of the countries in the developed world have been the driving force for much of the deforestation that has occurred from oil, mineral, and other resource extraction in these areas. Many of the developing countries cannot even afford to pay back the interest on the loans from the World Bank and the IMF. In some cases they have entered into “debt for nature swaps.” 7. Are you in favor of establishing more wilderness areas in the United States, especially in the lower 48 states (or in the country where you live)? Explain. What might be some drawbacks of doing this? Answer: Ensuring that current wilderness areas remain protected would be a main priority. Then an assessment of what other potential wilderness areas in the nation could be protected should be conducted, and decisions made on a case by case basis. Once an area has been given the designation of being a wilderness area, then it should keep that designation and not have it removed by the next government administration. There are drawbacks to this. Some people will be against protecting these areas and may wish to expand into them for development or resource extraction. Others may wish this to occur as it may limit their own ability to use the area as they would like to, for off-roading for example. 8. You are a defense attorney arguing in court for sparing a large area of tropical rainforest from being cut down. Give your three strongest arguments for the defense of this ecosystem. If you had to choose between sparing a tropical forest and sparing northern boreal forest of about the same size, which one would you try to save? Explain. Answer: The ecosystem is a vast storehouse of biodiversity, it provides materials, and helps to regulate global climatic and rainfall patterns. Tropical forests should be preferentially saved, because of the significantly higher proportion of biodiversity found therein. 9. Congratulations! You are in charge of the world. List the three most important features of your policies for using and managing: (a) forests, (b) grasslands, (c) nature reserves such as parks and wildlife refuges, (d) biological hotspots, and (e) areas with deteriorating ecosystems services. Answer: (a) I would ensure that sustainable harvesting practices took place in forested areas in order to supply and promote the production of sustainably grown wood products, manage the forests using best practices, and replant areas that have been cut down. (b) I would limit grazing rights on grasslands and remove subsidies that turn grasslands into cash crop-yielding areas, and minimize habitat fragmentation by limiting road construction and development of these areas. (c) I would limit the yearly use of nature reserves by putting a cap on the number of visitors who could access the area; increase the funding for park management and maintenance, and increase the amount of area in and around the reserves by purchasing and protecting more land. (d) I would limit development in biodiversity hotspots, and implement a habitat conservation plan to protect as many threatened and endangered species as possible. (e) Areas with deteriorating ecosystem services would be the focus of aggressive ecological restoration programs. These would involve community members, so that the local population would feel connected with the process. This would foster a cohesiveness that would help the projects to succeed. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: 1. How can brands effectively adapt their strategies to different geographical markets while maintaining a consistent global image? 2. What are the key challenges brands face when managing brand equity across different market segments, and how can they address them? Ecological Footprint Analysis Use the table below to answer the questions. Country Area of tropical rain forest (square kilometers) Area of deforestation per year (square kilometers) Annual rate of tropical forest loss A 1,800,000 50,000 B 55,000 3,000 C 22,000 6,000 D 530,000 12,000 E 80,000 700 1. What is the annual rate of tropical rain forest loss, as a percentage of total forest area, in each of the five countries? Answer by filling in the blank column on the table. 2. What is the annual rate of tropical deforestation collectively in all of the countries represented in the table? 3. According to the table, and assuming the rates of deforestation remain constant, which country’s tropical rain forest will be completely destroyed first? 4. Assuming the rate of deforestation in country C remains constant, how many years will it take for all of its tropical rain forests to be destroyed? 5. Assuming that a hectare (1.0 hectare = 0.01 square kilometer) of tropical rain forest absorbs 0.85 metric tons (1 metric ton = 2,200 pounds) of carbon dioxide per year, what would the total carbon loss or carbon footprint be in metric tons of carbon dioxide per year from deforestation in each of the five countries in the table? 1. Answer: E.g., the annual percentage rate of rain forest loss in country A is: 50,000 square kilometers/ 1,800,000 square kilometers x 100 = 0.028 X 100 = 2.8% per year. Country Area of tropical rain forest (square kilometers) Area of deforestation per year (square kilometers) Annual rate of tropical forest loss (% of total) A 1,800,000 50,000 2.8 B 55,000 3,000 5.5 C 22,000 6,000 27.3 D 530,000 12,000 2.3 E 80,000 700 0.9 2. Answer: Add the numbers in left column to get a total rain forest area of 2,487,000 square kilometers. Add the numbers in the right column to get the total area of 71,700 square kilometers of rain forest lost per year. The annual percentage rate of rain forest loss for all the countries is 71,700 square kilometers/2,487,000 square kilometers x 100 = 0.029 x 100 = 2.9% per year. 3. Answer: The annual rate of rain forest loss in each of the countries is: A: 50,000 square kilometers/ 1,800,000 square kilometers x 100= 0.028 X 100 = 2.8% per year. B: 3,000 square kilometers/55,000 square kilometers = 0.055 X 100 = 5.5% per year. C: 6,000 square kilometers/22,000 kilometers = 0.273 X 100 = 27.3% per year. D: 12,000 square kilometers/530,000 square kilometers = 0.023 X 100 = 2.3% per year. E.: 700 square kilometers/80,000 square kilometers = 0.009 X 100 = 0.9% per year. At a rate of 27.3% per year, country C’s rain forests would be completely destroyed first. 4. Answer: At a 27.3% rate of loss per year country C’s rain forests would be destroyed in 22,000 kilometers/6,000 kilometers = 3.7 years 5. Answer: The total carbon footprint per year for tropical rain forest loss in each country is: A: 50,000 square kilometers X 1 hectare/0.01 square kilometer = 5,000,000 hectares 5,000,000 hectares x 0.85 metric tons of carbon/hectare = 4,250,000 metric tons of carbon not absorbed per year B: 3,000 square kilometers X 1 hectare/0.01 square kilometer X 0.85 metric tons of carbon/hectare = 255,000 metric tons of carbon not absorbed per year C: 6,000 square kilometers X 1 hectare/0.01 square kilometer X 0.85 metric tons of carbon/hectare = 510,000 metric tons of carbon not absorbed per year D: 12,000 square kilometers X 1 hectare/0.01 square kilometer X 0.85 metric tons of carbon/hectare = 1,020,000 metric tons of carbon not absorbed per year E.: 700 square kilometers X 1 hectare/0.01 square kilometer X 0.85 metric tons of carbon/hectare = 59,500 metric tons of carbon not absorbed per year Solution Manual for Living in the Environment: Principles, Connections, and Solutions G. Tyler Miller, Scott Spoolman 9780538735346