The Value of Biodiversity The values people assign to biodiversity can be placed into two main categories: those that are intrinsic or inherent to the organism or ecosystem, and those which grow out of utilitarian, instrumental, or extrinsic uses or applications of biodiversity.
Intrinsic/Inherent Value Define intrinsic or inherent value. The intrinsic or inherent value of biodiversity refers to its right to exist, completely independent of any extrinsic or utilitarian values it might have to humans and to other biodiversity. Some of the more abstract extrinsic values are frequently misidentified as intrinsic values; for example, aesthetic value or the value of biodiversity to an ecosystem rather than to humans. This slide can serve as a starting point for discussion, depending on class time, size and level, any one of these topics could take 30-45 minutes to discuss. What role does intrinsic value play in existing conservation policy and laws? How do intrinsic values of biodiversity impact conservation decisions? Useful articles for this discussion include Lawton 1991, Callicott 1997, the Endangered Species Act, and the United Nations Charter on Nature 1982. Some teachers may prefer to present this slide, after the slides on extrinsic values, which are more concrete.
Prior to showing the next this slide and the following slide, ask the students to list some of the extrinsic or utilitarian values of biodiversity. This can be done as a group using brainstorming techniques, or in pairs or small groups initially and then as a class compiling the list. Using the list developed by the class examine the different categories of extrinsic values. Divide the list to show things that are “direct use” values or goods and those that are “indirect use” values or services . Then separate out those which are “non-use” values (i.e., bequest, existence, and potential values). Introduce the fact that there are several ways to categorize extrinsic values, and that many authors use slightly different methods, for example, some choose to place spiritual and cultural values as distinct from services such as pollination or nutrient cycling which are crucial to survival. Further, potential value is often included as a use value since potential value is based on the future use that biodiversity might have; others include this as a non-use value since it is, by nature, an abstract concept and the potential use that something might have is undetermined. Similarly with bequest value, if the idea is passing on something for the next generation to use, bequest value can be considered a kind of use value; but considering bequest value from a more abstract perspective renders bequest value closer to a non-use value, if the value lies simply in knowing that something will be there for the future regardless of whether it will be used. Were some values easier to think of than others? What kinds of values are easy to overlook? Categorizing Values In the conservation biology and ecological economics literature, there are many methods to categorize the value or worth of biodiversity. Often the value of biodiversity is subdivided into categories based on how biodiversity is used. Extrinsic value is a broad category encompassing many types of biodiversity values. Extrinsic values – also referred to as utilitarian or use values– include biodiversity’s direct or indirect use to other living things. This slide lists the major categories of extrinsic values, direct-use values or goods, and indirect-use values or services. It also includes a list of “non-use” values, potential, existence, and bequest values. Some include potential value as part of use value. We will examine each of these values in detail.
Direct Use Value: Goods This slide lists some of the different kinds of goods or products derived from biodiversity including food, building materials, fuel, paper products, fiber for clothing and textiles, industrial products, and medicine. In subsequent slides, several of these goods will be highlighted. [Note: The image depicts a man in Vietnam who is extracting bamboo for use as building material.]
Food Historically, humans have exploited thousands of plant species for food; today, however, most people on Earth depend on three staple crops (rice, wheat, and corn). Despite this dependence on few species, the genetic diversity in wild plants and animals remain important for creating new strains or breeds. Also, there are many species that one day could be a potential food source. Sorghum, emmer, and spelt, once widely grown grains, have been largely replaced by wheat. However, because of their unique environmental adaptations – sorghum, for example, can be grown in drier climates that do not support wheat – these grasses may become more important in the future if climatic conditions change. [Image is of rice paddies in Vietnam.]
Building Materials, Fuel, and Paper Products Trees and several grasses, most notably bamboo and rattan, are basic commodities used worldwide for building materials, paper products, and fuel. The worldwide production of timber and related products – including homes, furniture, mulch, chipboard, paper and packaging – is a multi-billion dollar industry. Outside of large market economies, products from particular species of wild-growing woody plants are key sources of shelter (e.g., termite-resistant support poles), household items (furniture, utensils, baskets, etc.), long-burning fuels, and dyes. One of the most important uses of wood is for fuel. According to the World Resources Institute, 63 percent of all harvested wood is used as fuel – whether burned directly or after being converted to charcoal. Fuelwood, charcoal, and other fuel from wood are the major sources of energy in low-income countries; the major consumers and producers of wood for fuel are Brazil, China, India, Indonesia, and Nigeria. [Image is of children in Vietnam preparing thatch for roofs.] Prior to showing the next slide ask students if they can guess how many of the leading prescription drugs have their origins in biodiversity. Students can also guess how many people in developing countries depend directly on plants for medicine.
Medicine People depend on biodiversity for medicinal purposes in two ways: directly as a primary source of medicine, and indirectly as a source of the chemical structures used in synthesizing drugs or service. [Image depicts medicinal herbs in a market in Bolivia.]
Traditional Medicine: Basis of Many Drugs This table gives some examples of Western drugs whose origins were from plants. Those noted in bold were originally used for tradition medicine. Instructor may choose to tell any number of stories of drug discovery based on plants used for traditional medicine, such as the use of foxglove for heart conditions, now the basis for digitoxin.
Indirect Use Values: Services This slide lists some of the different services provided by biodiversity. Ecosystem services encompass a wide variety of different resources, functions, and processes provided to humans and to other biodiversity. Unlike goods, these are often outside traditional economic markets, and thus more difficult to value monetarily. Several of the services of biodiversity will be examined in the following slides. Is it possible to place a value on ecosystem services, like nutrient cycling or watershed protection? Why is it helpful to do this? The article by Costanza and others (1997) can form the basis of a discussion on this subject
Global Processes: Atmospheric Regulation Forests and other vegetation modify climate in a variety of ways; they affect sun reflectance, water vapor release, wind patterns, and moisture loss. Photosynthetic biodiversity also has the potential to moderate the rising atmospheric carbon dioxide levels linked to global climate change by fixing carbon in organic matter. The evolution of photosynthesis is responsible for one of the most dramatic changes in the Earth's environment: the increase of atmospheric oxygen. 3.5 billion years ago, cyanobacteria, through the process of photosynthesis, released oxygen and helped to create the atmosphere we know today. The regulation of atmospheric oxygen depends on biodiversity. Carbon cycles between the land, atmosphere, and oceans through a combination of physical, chemical, geological, and biological processes. One key way biodiversity influences the composition of the earth’s atmosphere, and in turn its climate, is through its role in carbon cycling in the oceans
Global Processes: Climate Regulation Besides regulating the atmosphere’s composition, the extent and distribution of different types of vegetation over the globe modifies climate in three main ways: affecting the reflectance of sunlight ( radiation balance ); regulating the release of water vapor ( evapotranspiration ); and changing wind patterns and moisture loss ( surface roughness ). Vegetation absorbs water from the soil and releases it back into the atmosphere through evapotranspiration , which is the major pathway for water to move from the soil to the atmosphere. This release of water from vegetation cools the air temperature. In the Amazon region, vegetation and climate is tightly coupled; evapotranspiration of plants is believed to contribute fifty percent of the annual rainfall. Deforestation in this region leads to a complex feedback mechanism: as forest cover decreases, evapotranspiration rates decline, which in turn decreases rainfall and increases the area ’ s vulnerability to fire.
Soil and water conservation:
Pollination and Seed Dispersal Approximately 90% of flowering plants depend on pollination by bees, birds, bats and other pollinators for reproduction. The loss of pollinators and the services they provide would drastically reduce the size of food harvests and threaten non-agricultural species with extinction. Besides pollination, biodiversity provides many other services to agriculture not detailed here, such as natural pest control and a genetic library for crop and livestock improvement.
Source of Inspiration or Information Humans have always relied on biodiversity to help understand and solve problems in the world around us. This slide examines some of the ways that biodiversity inspires us, from biomimicry to applied biology and medical models, as well as for scientific research and education. Discoveries made during scientific research have revolutionized many fields. A heat-tolerant enzyme found in bacteria living in the hotsprings of Yellowstone National Park in the United States is the underpinning of much of today’s genetic and biotechnology research. These heat-tolerant enzymes, known as taq enzymes, are used in the polymerase chain reaction (PCR) to replicate genetic material. From airplanes to velcro, the natural world has provided a source of inspiration to overcome challenges. This phenomenon is sometimes termed “biomimicry” as the technological innovation mimics something from the biological world. For example, Velcro was patterned after cockleburs, a plant that disperses its seeds via its sticky seed pods that attach to people or animals as they walk through a meadow.
Medical Models Biodiversity also provides a source of medical models to better understand diseases. Understanding how bears are able to hibernate may uncover new ways to assist trauma patients and treat kidney disease and osteoporosis. Bears hibernate for 150 days, stopping all normal functions (such as eating, drinking, urinating, and defecating). Bears are able to accomplish this arrest of bodily functions by lowering their body temperature only slightly – by 5 degrees Celsius. Scientists have discovered a protein that induces hibernation, slowing organ metabolism and blood coagulation. One application of this discovery could be to slow bleeding in trauma patients while in transit to the emergency room. During hibernation, bears are also able to recycle their urine and use it to rebuild tissue. This ability may be useful for treating kidney illnesses. Finally, bears also manage to survive hibernation with minimal bone loss, which may provide solutions for people suffering from osteoporosis.
Aesthetic Value How do aesthetic values differ between cultures?
Ecological Value: Does Diversity Make Communities More Resilient
Kelp Forest Food Webs
Non-Use or Passive Values There are several less tangible values that are sometimes called non-use or passive values, for things that we don’t use but would feel a loss if they were to disappear; these typically include existence value , the value of knowing something exists even if you will never use it or see it, and bequest value , the value of knowing something will be there for future generations. Economists sometimes use surveys to estimate these values, asking for example what someone is willing to pay to simply know that tigers exist even if they will never see or use one. Potential or option value refers to the use that something may have in the future; some authors consider this a form of use value, but here it is included within the passive values based on its abstract nature, for example, a plant may have a potential value but until this value is realized, this value is uncertain; once the plant’s value is recognized, it is a use value.
CHAPTER ONEBIODIVERSITY AND CONSERVATION
BiodiversityBiodiversity, or biological diversity = the sum of an area’s organisms, considering the diversity of species, their genes, their populations, and their communitiesThere is no one exact definition of biodiversity; people have conceived of it in many ways.
Components of biodiversityGenetic Speciesdiversity diversity Ecosystem diversity
Components of biodiversity:Genetic diversity – genetic variation within populations or species.Species diversity – numbers of species within an areaEcosystem diversity – variation among ecosystems, communities, landscapes
GENETIC DIVERSITYGenetic diversity can refer to the sum total of all different forms of genetic information carried by a particular species, or by all organisms on Earth. Within each species, genetic diversity refers to the total of all different forms of genes present in that species.
Genetic diversity - genetic variability or diversitywithin a species, i.e. between the individuals of aspeciesExample ; 5,000 recorded varieties of mango 88,000 recorded varieties of Oryza sativa
Genetic diversity• Includes the differences in DNA composition among individuals within a given speciesAdaptation to particular environmental conditions may weed out genetic variants that are not successful.But populations benefit from some genetic diversity, so as to avoid inbreeding or disease epidemics.
Species diversity• The number or variety of species in a particular regionSpecies richness = number of speciesSpecies = a particular type of organism; a population or group of populations whose members share certain characteristics and can freely breed with one another and produce fertile offspring
To date, biologists have identified and named more than 1.8 million species, and they estimate that at least 30 million more are yet be discovered.
Species diversity - diversity between differentspeciesExample ; Felis tigris Felis domestica
Ecosystem diversityEcosystem diversity refersto the variety of habitats,communities, andecological processes inthe biosphere.
The Value of BiodiversityWhy is biodiversity important?Biodiversity’s benefits to society include contributions to medicine and agriculture, and the provision of ecosystem goods and services.
Biodiversity is a natural asset that provides goods and servicesFood RecreationMedicine InspirationMaterials Spiritual stimulationChemical products ContemplationWater & soil supply Peace of mindClimate regulation Religious experiencesScience & technology It contributes to the It contributes to theSewage & garbage treatment social, economic, social, economic,Biological control intellectual and intellectual andPollination spiritual development spiritual development of society. of society.
Extrinsic ValueExtrinsic value is a broad category encompassing many types of biodiversity values.Extrinsic values – also referred to as utilitarian or use values 19
Extrinsic values – utilitarian or use values– include biodiversity’s direct or indirect use to other living things 20
Categorizing ValuesDirect Use Value(Goods) Indirect Use Value Non-Use Values (Services)Food, medicine, building Atmospheric and climate Potential (or Option) Future value either as amaterial, fiber, fuel regulation, pollination, Value good or service nutrient recycling Cultural, Spiritual and Existence Value Value of knowing Aesthetic something exists Bequest Value Value of knowing that something will be there for future generations
Besides regulating the atmosphere’s composition, the extent and distribution of different types of vegetation over the globe modifies climate in three main ways: i) affecting the reflectance of sunlight (radiation balance) ii) regulating the release of water vapor (evapotranspiration) iii) changing wind patterns and moisture loss (surface roughness). 33
Vegetation absorbs water from the soil and releases it back into the atmosphere through evapotranspiration, which is the major pathway for water to move from the soil to the atmosphere. This release of water from vegetation cools the air temperature. 34
In the Amazon region, vegetation and climate is tightly coupled; evapotranspiration of plants is believed to contribute fifty percent of the annual rainfall.Deforestation in this region leads to a complex feedback mechanism: as forest cover decreases, evapotranspiration rates decline, which in turn decreases rainfall and increases the area’s vulnerability to fire. 35
Biodiversity is also important for global soil and water protection.Terrestrial vegetation in forests and other upland habitats maintain water quality and quantity, and control soil erosion. 37
In watersheds where vegetation has been removed, flooding prevails in the wet season and drought in the dry season.Soil erosion is also more intense and rapid, causing a double effect: removing nutrient-rich topsoil and leading to siltation in downstream riverine and ultimately oceanic environments. 38
This example focuses on services provided by coastal wetlands and mangroves.Wetlands are ecosystems where water is present at or near the soil surface or root zone for part or all of the year; the vegetation found in these regions is adapted for these conditions. 39
Wetlands are among the worlds most productive ecosystems and provide a range of ecological services, including - filtering excess nutrients - trapping sediments - minimizing damage to coastal areas from floods and waves - providing critical habitat for many birds, fish, and shellfish – in particular the juvenile stage of several commercial fish. 40
The services of a wetland are not easy to replace if they are removed.Dams and water treatment facilities are the engineering equivalent of a wetland, but are often very expensive to build and maintain.According to the US Army Corps of Engineers, without the 3,800 hectares of wetlands that exist along the Charles River in Boston, Massachusetts, flood damage would cost $17 million per year. This is one method to establish a value for biodiversity – by its “replacement value 41
The flow of nutrients through an ecosystem is critical to its health.Biodiversity (including algae, fungi, bacteria, and insects) decompose organic matter, recycling and returning nutrients to soils. [The image is of a decomposing deer.] 43
Medical Models Hibernating bears may improve the treatment of: trauma patients kidney disease osteoporosisSource: New Jersey Fish and Wildlife
Biodiversity also provides a source of medical models to better understand diseases.Understanding how bears are able to hibernate may uncover new ways to assist trauma patients and treat kidney disease and osteoporosis. 47
Bears hibernate for 150 days, stopping all normal functions (such as eating, drinking, urinating, and defecating).Bears are able to accomplish this arrest of bodily functions by lowering their body temperature only slightly – by 5 degrees Celsius.Scientists have discovered a protein that induces hibernation, slowing organ metabolism and blood coagulation. 48
One application of this discovery could be to slow bleeding in trauma patients while in transit to the emergency room.During hibernation, bears are also able to recycle their urine and use it to rebuild tissue. This ability may be useful for treating kidney illnesses.Finally, bears also manage to survive hibernation with minimal bone loss, which may provide solutions for people suffering from osteoporosis 49
Another example of cultural values is the aesthetic value that different cultures find in biodiversity.In fact many of the first national parks and protected areas were created to protect beautiful and awe-inspiring landscapes. 51
Ecological Value: Does Diversity Make Communities More Resilient? Resilient ecosystems are characterized by: Constancy (Lack of fluctuation) Inertia (Resistance to perturbation) Renewal (Ability to repair damage) Not all species are critical to an ecosystems function; many fill redundant roles; basis for community resilience and integrity If too many species or keystone species are lost, eventually it leads to the failure of ecosystem function
Natural communities are finely tuned systems, where each species has an ecological value to the other species that are part of that ecosystem.Species diversity increases an ecosystem’s stability and resilience, in particular its ability to adapt and respond to changing environmental conditions.If a certain amount, or type (such as a keystone species) of species are lost, eventually it leads to the loss of ecosystem function.Many ecosystems though have built-in redundancies so that two or more species’ functions may overlap. 53
Because of these redundancies, several changes in the number or type of species may not impact an ecosystem. However, not all species within an ecosystem are of the same importance.Species that are important due to their sheer numbers are often called dominant species.These species make up the most biomass of an ecosystem.Species that have important ecological roles that are greater than one would expect based on their abundance are called keystone species. 54
These species are often central to the structure of an ecosystem;removal of one or several keystone species may have consequences immediately, or decades or centuries later (Jackson et al. 2001).Ecosystems are complex and difficult to study, thus it is often difficult to identify keystone species.In the following example, the impact of removing an individual or several keystone species from kelp forest ecosystems in the Pacific is examined. 55
Kelp forests, as their name suggests, are dominated by kelp, a brown seaweed of the family Laminariales.They are found in shallow, rocky habitats from temperate to subarctic regions, and are important ecosystems for many commercially valuable fish and invertebrates.Sea otters (Enhydra lutris) are considered a keystone species, as a result of their role in structuring the kelp forest habitats found off the coast of western North America. 57
The illustrations show kelp forest food webs in the presence and absence of sea otters, and demonstrate how the loss of this keystone species can drastically alter and reduce ecosystem function and complexity. 58
Non-Use or Passive Values Existence value Bequest value Potential or Option value
Valuing Biodiversity Biodiversity is one of Earth’s greatest natural resources. When biodiversity is lost, significant value to the biosphere and to humanity may be lost along with it. Biodiversity’s benefits to society include contributions to medicine and agriculture, and the provision of ecosystem goods and services.
Biodiversity and Medicine Wild species are the original source of many medicines. For example, a foxglove plant contains compounds called digitalins that are used to treat heart disease. These plant compounds are assembled according to instructions coded in genes. The genetic information carried by diverse species is like a “natural library” from which we have a great deal to learn.
Biodiversity and Agriculture Most crop plants have wild relatives. For example, wild potatoes in South America come in many colorful varieties. These wild plants may carry genes we can use —through plant breeding or genetic engineering—to transfer disease or pest resistance, or other useful traits, to crop plants.
Biodiversity and Ecosystem ServicesThe number and variety of speciesin an ecosystem can influence thatecosystem’s stability, productivity,and value to humans.
Sometimes the presence or absence of a single keystone species, like the sea otter, can completely change the nature of life in an ecosystem. When the otter population falls, the population of its favorite prey, sea urchins, goes up. Population increases in sea urchins cause a dramatic decrease in the population of sea kelp, the sea urchin’s favorite food. Also, healthy and diverse ecosystems play a vital role in maintaining soil, water, and air quality
Benefits of biodiversityPreserving biodiversity preserves ecosystem services, and directly provides things of pragmatic value to us. • Food, fuel, and fiber • Shelter and building materials • Air and water purification • Waste decomposition • Climate stabilization and moderation • Nutrient cycling • Soil fertility • Pollination • Pest control • Genetic resources
Benefits of biodiversity: Food security Many species not now commonly used for food could be. Genetic diversity within crop species and their relatives enhances our agriculture and provides insurance against losses of prevalent strains of staple crops. Figure 15.11
Benefits of biodiversity: Medicine Many species can provide novel medicines; we don’t want to drive these extinct without ever discovering their uses. Ten of our top 25 drugs come directly from wild plants; the rest we developed because of studying the chemistry of wild species.
Benefits of biodiversity: Economic benefitsFor all nations, ecotourism can be a major contributor to the economy—especially for developing nations rich in biodiversity.Affluent tourists pay good money to see wildlife, novel natural communities, and protected ecosystems.
Benefits of biodiversity: “Biophilia”Biophilia = human love for and attachment to other living things; “the connections that human beings subconsciously seek out with the rest of life” e.g., Affinity for parks and wildlife Keeping of pets Valuing real estate with landscape views Interest in escaping cities to go hiking, birding, fishing, hunting, backpacking…
Hot- spots of Biodiversity A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is threatened with destruction. An area is designated as a hot spot when it contains at least 0.5% of plant species as endemic. There are 25 such hot spots of biodiversity on a global level.
Criteria for determining hot-spots No. of Endemic Species i.e. the specieswhich are found no where else. Degree of threat, which is measured interms of Habitat loss.
Threats to BiodiversityWhat are the most significant threats to biodiversity?
Biodiversity loss and species extinctionExtinction = last member of a species dies and the species vanishes forever from EarthExtirpation = disappearance of a particular population, but not the entire species globallyThese are natural processes.On average one species goes extinct naturally every 500–1,000 years—this is the background rate of extinction.99% of all species that ever lived are now extinct.
. Mass extinctions Earth has experienced five mass extinction events in which over half its species were wiped out suddenly. Figure 15.8
Today’s mass extinctionCurrently Earth is undergoing its sixth mass extinction —because of us.Humans have increased the extinction rate by a factor of 1,000.1,100 species are known to have gone extinct in the past 400 years.The Red List, from the IUCN, lists species that today are facing high risks of extinction.
Today’s mass extinction Species of large mammals and birds plummeted with the arrival of humans, independently, on each of three continents— suggesting that human hunting was the cause. Figure 15.9
Causes of species extinctionPrimary causes spell “HIPPO”: • Habitat alteration • Invasive species • Pollution • Population growth • Overexploitation
“HIPPO”: Habitat alterationThe greatest cause of extinction todayAccounts for 85% of population declines of birds and mammalsHabitat change hurts most organisms because they are adapted to an existing habitat.Alteration due to: Forest clearing Urban development Agriculture Global climate change
“HIPPO”: Invasive speciesAccidental or intentional introduction of exotic species to new areasMost do not establish or expand, but some do—likely because they are “released” from limitations imposed by their native predators, parasites, and competitors.In today’s globalizing world, invasive species have become perhaps the second- worst threat to native biota.
“HIPPO”: Invasive species Examples: • Gypsy moth • Mosquito fish • European starling • Zebra mussel • Indian • Kudzu mongoose • Asian long- Caulerpa horned beetle algae • Rosy wolfsnail Cheatgrass • Cane toad Brown tree snake • Bullfrog Figure 15.10
“HIPPO”: PollutionAir and water pollution; agricultural runoff, industrial chemicals, etc.Pollution does serious and widespread harm, but is not as threatening as the other elements of HIPPO.
“HIPPO”: Population growthHuman population growth exacerbates every other environmental problem.Magnifies effects of the other elements of HIPPO: More people means more habitat change, more invasive species, more pollution, more overexploitation.Along with increased resource consumption, it is the ultimate reason behind proximate threats to biodiversity.
“HIPPO”: OverexploitationTwo meanings: Overharvesting of species from the wild (too much hunting, fishing…) Overconsumption of resources (too much timber cutting, fossil fuel use…)Usually overexploitation is not the sole cause extinction, but it often contributes in tandem with other causes.
Causes of species extinctionIn most cases, extinctions occur because of a combination of factors. e.g., current global amphibian declines are thought due to a complex combination of: • Chemical contamination • Disease transmission • Habitat loss • Ozone depletion and UV penetrance • Climate change • Synergistic interaction of these factors
Benefits of biodiversityPreserving biodiversity preserves ecosystem services, and directly provides things of pragmatic value to us. • Food, fuel, and fiber • Shelter and building materials • Air and water purification • Waste decomposition • Climate stabilization and moderation • Nutrient cycling • Soil fertility • Pollination • Pest control • Genetic resources
Conservation biology Scientific discipline devoted to understanding the factors, forces, and processes that influence the loss, protection, and restoration of biological diversity within and among ecosystems. Applied and goal-oriented: Conservation biologists intend to prevent extinction. This discipline arose in recent decades as biologists grew alarmed at the degradation of natural systems they had spent their lives studying. Figure 15.13
Conservation approaches: Umbrella speciesWhen habitat is preserved to meet the needs of an “umbrella species,” it helps preserve habitat for many other species. (Thus, primary species serve as an “umbrella” for others.) Large species with large home ranges (like tigers and other top predators) are good umbrella species. So are charismatic ones that win public affection, like the panda.
Conservation approaches: Endangered speciesTrying to preserve single species threatened with extinction is the goal of endangered species laws, although they often also achieve umbrella conservation.U.S. Endangered Species Act, 1973: • Restricts actions that would destroy endangered species or their habitats • Forbids trade in products from species • Prevents extinction, stabilizes and recovers populations
Conservation approaches: Endangered speciesThe ESA has had notable successes: Bald eagle Peregrine falcon 40% of all declining populations held stableHowever, there is much popular resentment against the ESA:Many citizens believe it will restrict their freedom if endangered species are found on their land.
Conservation approaches: Captive breedingMany endangered species are being bred in zoos,to boost populations and reintroduce them into the wild. This has worked so far for the California condor (in photo, condor hand puppet feeds chick so it imprints on birds, not humans). But this is worthless if there is not adequate habitat left in the wild. Figure 15.17
Conservation approaches: CloningA newly suggested approach is to use molecular techniques to clone endangered or even extinct species, raise them in zoos, and reintroduce them to the wild.Even if this succeeds technically, though, it will be worthless if there is not adequate habitat and protection left for them in the wild.
Conservation approaches: International treatiesVarious treaties have helped conserve biota.A major one is CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, prepared in 1973.It bans international trade and transport of body parts of endangered organisms.
Conservation approaches: International treatiesThe Convention on Biological Diversity (CBD), from the Rio Conference in 1992, aims to: • Conserve biodiversity • Use it sustainably • Ensure fair distribution of its benefitsThe CBD has been signed by 188 nations, but not by the United States.
Conservation approaches: Biodiversity hotspotsBiodiversity hotspot = an area that supports an especially high number of species endemic to the area, found nowhere else in the world Endangered golden lion tamarin, endemic to Brazil’s Atlantic rainforest, which has been almost totally destroyed Figure 15.18
Conservation approaches: Biodiversity hotspotsGlobal map of biodiversity hotspots, as determined by Conservation International Figure 15.19
Conclusions: ChallengesWe still have little idea of how many species inhabit our planet.We have set the sixth mass extinction in motion.Population declines, extirpations, and extinctions result from habitat alteration, invasive species, pollution, population growth, and overexploitation.Fragmentation of habitats causes loss of species from habitat islands.Conservation biology is fighting an uphill battle to save species, habitats, and ecosystems.
Conclusions: SolutionsBiologists are making strides in determining how many species inhabit our planet.There is still time to halt the sixth mass extinction.We have ways to minimize habitat alteration, invasive species, pollution, and overexploitation, but success will ultimately depend on halting human population growth.Fragmented habitats can be restored, but preserving areas before they are fragmented is best to avoid species loss.Conservation biology has developed numerous and varied ways to save species, habitats, and ecosystems.
QUESTION: ReviewWhich of these pairs of terms is included in the acronym “HIPPO” that describes causes of biodiversity loss? a. Pollution and Indicator species b. Harvesting and Population decline c. Habitat alteration and Invasive species d. Overexploitation and Pollination e. Indicator species and Population growth
QUESTION: ReviewWhich is NOT a benefit of biodiversity to humans? a. Economic benefits through ecotourism b. New potential sources of food c. New potential sources of drugs d. Ecosystem services e. All of the above are benefits of biodiversity.
QUESTION: ReviewWhich has NOT been an approach of conservationbiologists? a. Identifying and mapping areas with large numbers of endemic species. b. Applying island biogeography theory to habitat fragments. c. Breeding animals in captivity. d. Requiring landowners to give up their land. e. Working with local communities to get them invested in conservation.
QUESTION: Weighing the IssuesWhen North American pharmaceutical companies go“bioprospecting” in developing countries for compounds for newdrugs and medicines, should they be required to pay the hostcountry for its biodiversity? a. Yes; the biodiversity is a natural resource of the host country, and it should be paid a fee up front. b. Yes; the biodiversity is a natural resource of the host country, and it should share in any eventual profits from any medicines developed. c. No; the company is the one doing all the work, so all profits should go to the company.
QUESTION: ViewpointsAre parks and protected areas the best strategy forprotecting biodiversity? a. Yes; it is absolutely necessary to preserve untrammeled habitat for species to persist. b. No; parks won’t matter because climate change will force the biota out of them. c. No; it is more effective to work with local people and give them economic incentives to conserve nature d. Both parks and other strategies are necessary.