Biology Sylvia S. Mader Michael Windelspecht Chapter 47 Conservation of Biodiversity Lecture Outline Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. See separate FlexArt PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. 1 Outline 47.1 Conservation Biology and Biodiversity 47.2 Value of Biodiversity 47.3 Causes of Extinction 47.4 Conservation Techniques 2 47.1 Conservation Biology and Biodiversity Considers all aspects of biodiversity General goal is conserving natural resources for this and future generations Primary goal is the management of biodiversity The variety of life on Earth 3 Conservation Biology and Biodiversity For conservation biology to be effective, scientists must evaluate larger connections within the biosphere High level of biodiversity is desirable Causes of present-day extinction, how to prevent future extinctions from occurring, and consequences of reduced biodiversity Bioinformatics is utilized to protect biodiversity Collecting of, analyzing, and making readily available biological information, using modern computer technology 4 Conservation Biology and Biodiversity Biodiversity At its simplest level, biodiversity refers to the variety of species on Earth Estimated that between 10 and 50 million species currently exist Endangered Species One that is in peril of immediate extinction throughout all or most of its range Threatened Species Organisms that are likely to become endangered in the near future 5 Conservation Biology and Biodiversity Biodiversity Ecologists describe biodiversity as a combination of three levels of biological organization: Genetic diversity Community diversity Landscape diversity 6 Conservation Biology and Biodiversity Biodiversity Genetic diversity refers to variations among the members of a population Populations with high genetic diversity are more likely to have some individuals that can survive a change in the structure of their ecosystem If a species population is small and isolated, it is more likely to become extinct due to a limited genetic diversity. 7 Conservation Biology and Biodiversity Biodiversity Ecosystem diversity is dependent on interactions of species in a particular area A diverse community composition will increase the levels of biodiversity in the biosphere An effective approach to conservation is to conserve species that play a key role within the ecosystem Saving an entire community can save many species 8 Conservation Biology and Biodiversity Biodiversity Landscape diversity involves a group of interacting ecosystems within one landscape Landscape Ex: mountains, rivers, grasslands Fragmentation of the landscape reduces reproductive capacity and food availability 9 Number of Described Species 10 insects 900,000 plants 240,000 animals 280,000 fungi 63,665 protists 55,000 bacteria and archaea 5,000 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Conservation Biology and Biodiversity Distribution of Biodiversity Biodiversity is not evenly distributed throughout the biosphere Biodiversity is highest at the tropics Biodiversity hotspots Contain about 44% of known higher plant species and 35% of terrestrial vertebrate species Represent only about 1.4% of earths land area 11 47.2 Value of Biodiversity Direct Value A great number of species perform services from which humans can derive an economic value. These include: Medicinal value Agricultural value Consumptive Use Value 12 Value of Biodiversity Direct Value (continued) Medicinal Value Most of the prescription drugs currently used in the United States were originally derived from living organisms Worth about $200 billion Ex: Rosy Periwinkle Chemicals from this plant are currently used to treat leukemia and Hodgkin disease These drugs have significantly increased survival rates for children Other examples include the use of penicillin in the treatment of bacterial infections; the use of blood from Limulus used to ensure that medical devices remain free of bacteria 13 Value of Biodiversity Direct Value (continued) Agricultural Value Wheat, corn, and rice are derived from wild plants that were modified to increase their yield Natural predators of plant pests have been introduced to agricultural systems to reduce the impact of the pest on plant yields 14 Value of Biodiversity Direct Value (continued) Consumptive Use Value Humans have had success cultivating crops, domesticating animals, growing trees in plantations, etc. However, most freshwater and marine harvests must be hunted, rather than grown via aquaculture, for human consumption Additional products associated with the environment are sold commercially Wild fruits, vegetables, skins, fibers, beeswax and seaweed Profits from the sale of these products provide an economic benefit to the human population 15 Value of Biodiversity Indirect Value Based on the services ecosystems provide simply by their own existence. These include: Biogeochemical cycles Waste recycling Provision of Fresh Water Prevention of Soil Erosion Regulation of Climate Ecotourism 16 Value of Biodiversity Indirect Value (continued) Biogeochemical Cycles The biodiversity within ecosystems contributes to the workings of the water, carbon, nitrogen, phosphorous, and other biogeochemical cycles Humans are dependent upon these cycles for fresh water, removal of carbon dioxide from the atmosphere, uptake of excess soil nitrogen, and provision of phosphate 17 Value of Biodiversity Indirect Value (continued) Waste Recycling Decomposers break down dead organic matter and other types of wastes into inorganic nutrients used by producers within ecosystems. This function aids humans The human population dumps millions of tons of waste material into natural ecosystems each year If it were not for decomposition this waste would soon cover the entire surface of the Earth 18 Value of Biodiversity Indirect Value (continued) Provision of Fresh Water The water cycle provides fresh water to terrestrial ecosystems Humans use this fresh water in innumerable ways Freshwater ecosystems provide us with a large diversity of species we can use as a source of food Forests and some other natural ecosystems soak up water and release it at a regular rate, thereby reducing flooding 19 Value of Biodiversity Indirect Value (continued) Prevention of Soil Erosion Intact ecosystems naturally retain soil and prevent soil erosion The importance of this attribute is particularly observed after deforestation Results in silt buildup 20 Value of Biodiversity Indirect Value (continued) Regulation of Climate Trees provide shade and reduce the need for fans and air conditioners in the summer Globally, forests restore the climate by incorporating carbon dioxide from the atmosphere Reduction of forests reduces the carbon dioxide uptake and oxygen output through photosynthesis 21 Value of Biodiversity Indirect Value (continued) Ecotourism In the United States, nearly $4 billion is spent on fees, travel, lodging, and food within natural settings Many underdeveloped countries in tropical regions take advantage of this by offering ecotours of the local biodiversity 22 Value of Biodiversity Biodiversity and Natural Ecosystems Large-scale changes in biodiversity have significant impacts on ecosystems: Ecosystem performance improves with increasing biodiversity Rate of photosynthesis increases as biodiversity increases 23 1248 Rate of Photosynthesis Number of Plant Species Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 24 Influence of Biodiversity on Community Productivity 47.3 Causes of Extinction Known causes of species extinction are due to: Habitat loss (85%) Exotic species (50%) Pollution (24%) Overexploitation (17%) Disease (3%) 25 Causes of Extinction Habitat Loss Occurs in all ecosystems Recent concern focuses on tropical rain forests and coral reefs because they are rich in species Loss of habitat affects terrestrial, freshwater, and marine biodiversity 26 Habitat Loss 27 0 Roads cut through forest Forest occurs in patches Destroyed areas c. Wildlife habitat is reduced. b. Macaws a. Threats to wildlife % Species Affected by Threat Disease Overexploitation Pollution Exotic Species Habitat Loss Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b: IT Stock/PunchStock RF; c (top): Courtesy Woods Hole Research Center; c (center): Courtesy R.O. Bierregaard; c (bottom): Courtesy Thomas Stone, Woods Hole Research Center Causes of Extinction Exotic Species Nonnative species that migrate, or are introduced, into a new ecosystem Humans introduce exotic species into ecosystems through: Colonization Horticulture and Agriculture Accidental Transport 28 Exotic Species 29 a.b. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: Chuck Pratt/Bruce Coleman, Inc.; b: Chris Johns/National Geographic Image Collection Causes of Extinction Impact of Exotics on Islands Islands are particularly susceptible to environmental discord due to the introduction of exotic species Island inhabitants have native species closely adapted to one another and do not compete well with exotic species Ex: Myrtle tree introduced to the Hawaiian Islands Brown tree snake introduced to Pacific islands 30 Causes of Extinction Pollution Any environmental change that adversely affects living things Third main cause of extinction Biodiversity is particularly threatened by Acid deposition Eutrophication Ozone depletion Synthetic organic chemicals 31 Causes of Extinction Pollution (continued) Acid Deposition Sulfur dioxides and nitrogen oxides in automobile gas react with water in the atmosphere to form acids that are returned to Earth as either wet or dry deposition Weakens trees and increases their susceptibility to disease Kills small decomposers and invertebrates, thereby disrupting entire ecosystems 32 Causes of Extinction Pollution (continued) Eutrophication Excess nutrient runoff from terrestrial environments result in algal growth in lakes As these algae die, the decomposers in the lake break them down and reduce the amount of oxygen in the lake. Results in death of fish and other aquatic organisms 33 Causes of Extinction Pollution (continued) Ozone Depletion Ozone (O 3 ) protects the surface of the Earth from harmful UV rays Chlorofluorocarbons released from products such freon used in older refrigerators destroy ozone Leads to impaired crop and tree growth, death of plankton, and impairment of immune system function 34 Causes of Extinction Pollution (continued) Organic Chemicals Organic chemicals such as nonylphenols used in a variety of human products mimic the effect of hormones Harms wildlife 35 Causes of Extinction Climate Change Refers to recent changes in the Earths climate Increased temperature of the Earth results in drastic climatic changes Temperature increase is caused, in part, by increased concentrations of greenhouse gases, such as CO 2 that serve to trap heat within the atmosphere Results in ecosystem disruption and extinction 36 Climate Change 37 Mean Global Temperature Change (C) Year a. b. 0.5 most probable temperature increase for 2 CO 2 maximum likely increase minimum likely increase b: Courtesy Walter C. Jaap/Florida Fish & Wildlife Conservation Commission Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Causes of Extinction Overexploitation The number of individuals taken from the population is so great that the population becomes severely reduced in numbers Positive feedback cycle The smaller the population, the more valuable its members, and the greater the incentive to capture the few remaining organisms The market forces driving overexploitation: Exotic Pets Poaching Overfishing 38 Overexploitation of Asian Turtles Collection and trade of terrestrial and freshwater turtles for human consumption has surged in Asia 40% - 60% of all species are currently endangered Due to their life history characteristics (slow growth, low reproductive rates), wild populations are not likely to recover after they have been plundered. Major Challenges Today and in the Future include: Lack of knowledge of range, natural history, and conservation needs of turtle species Need for legislation of diverse countries to be passed that ensures the long-term survival of turtle populations Threat of invasive species and spread of disease from aquaculture 39 47.4 Conservation Techniques Habitat preservation and restoration are important in preserving biodiversity Habitat Preservation Biodiversity hotspots, small areas with large numbers of endemic species not found anyplace else, are important targets for conservation Keystone Species Species that influence the viability of a community Extinction of these species can lead to additional extinctions and loss of biodiversity Flagstone Species Charismatic species that evoke a strong emotional response in humans 40 Conservation Techniques Habitat Preservation (continued) Metapopulation Small population isolated because of habitat fragmentation Source Population One that most likely lives in a favorable area and its birth rate is most likely higher than its death rate Sink Population Organisms that have moved from a source population to an environment not as favorable and where the birth and death rates are approximately equal 41 Conservation Techniques Landscape Preservation Landscape protection for one species benefits other wildlife in the same space The Edge Effect The edge around a patch of habitat has conditions different from the patch interior An edge reduces the amount of habitat typical for an ecosystem Can result in a significant reduction in population size 42 Edge Effect 43 habitat patch 30.55% 43.75% 64% 88.8% a. b. area subject to edge effect increasing percentage of patch influenced by edge effects brown-headed cowbird chick yellow warbler chick Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b: Jeff Foott Productions Conservation Techniques Habitat Restoration Restoration ecology seeks scientific ways to return ecosystems to their state prior Three Principles of restoration ecology: Begin as soon as possible before remaining fragments are lost Once natural history is understood, use biological techniques to mimic natural processes Goal is sustainable development 44