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Biodiversity: why is it important? Gwen Raitt Biodiversity and Conservation Biology Department Available at http://planet.uwc.ac.za/nisl/Biodiversity/ BCB 705: Biodiversity Some things to consider The question asked on the title slide assumes that biodiversity is important, is it? Biodiversity has been subject to huge losses (mass extinctions) before. Why should we worry about it? Is our anthropocentric view of biodiversity the only valid view? “What sort of world do we want to live in?” (p. 87 Gaston & Spicer 1998). “What sort of world are we prepared to pay to live in?” (p. 87 Gaston & Spicer 1998) If biodiversity is important, how do we use it sustainably? Ways of assigning value to biodiversity This does not only consider monetary value. Non-use Values Use Values Indirect Direct Intrinsic Value Non-use values Values based on potential: Option Value Bequest Value Values based on human awareness and perceptions: Existence Value Aesthetic Value Indirect use values Nutrient Cycling Waste Treatment Decomposition Soil Fertility Soil Formation & Maintenance Erosion Control Gas Regulation Climate Regulation + Abiotic = Habitat Carbon Sequestration Air Purification Natural Organisms form Ecosystems Water Purification Food Pollination Water Regulation Trophic Levels Biological Control Disturbance Control Direct use – indicator of environmental resources Organisms may serve as indicators of desired resources. To illustrate, certain plant species serve as reliable indicators of desired environmental conditions. Some plant species have affinities to certain metals. Indicator of environmental resources – dependence and effect The use of plants as indicators of environmental resources is dependent on autecological knowledge of the plant species. Such knowledge depends on studies of the species in its natural habitat which requires all the ecosystem services to maintain it. Unfortunately the use of the resources indicated by the plant species tends to be detrimental to the continued existence of all the native species in that area. Direct use – food production Most of what we eat is produced by living organisms – either through agriculture or through harvesting from the wild. Subsistence farmers particularly benefit from biodiversity. Food additives Aids to food production – e.g. pesticides, insecticides, fungicides and fertilisers. Genetic improvement of domesticated species. Non-Use Value = Source of new species for agricultural use. Food production – effects and dependence The survival of species harvested from the wild is threatened. Wild harvesting is dependent on all the different ecosystem services to sustain the production of the harvested species. Cropland uses space. Agriculture is dependent on ecosystem services to provide a suitable environment for the production organisms (plant and animal). The ecosystem services include biological control of soil organisms, nutrient cycling, pollination, soil formation and maintenance, soil fertility and water purification for plant production and all of the above with the addition of food sources for animal production. Direct use – biological control The direct use of a natural enemy to control a pest organism. See the Invasion Biology Course (chapter 8) for more detail. Biological control – dependence Biological control makes direct use of the natural biological control exerted by ecosystems in an unnatural context. The biological control agent is dependent on all ecosystem services that support its host, e.g. nutrient cycling and habitat. The maintenance of a habitat involves all the other ecosystem services. Direct use – medicine Commercial production of plants for the extraction of medicines and direct commercial production of biodiversity derived medicines are important sources of medications. Traditional medicines (see picture). Animals for product testing Non-Use Value = Source of new medicines Medicine – dependence Agriculturally propagated medicinal species require the ecosystem services that are required by agriculture. Chemical production of medicines is dependent on the water and air purification and waste treatment services of ecosystems. Wild harvesting for traditional or other use is dependent on all the different ecosystem services to sustain the production of the harvested species. Animal testing of medicines requires a supply of food for the animals. Many primate species are used to test drugs. Direct use – industry Raw materials for industrial use include timber, rattans, fibers, oils, fats, resins, waxes, dyes, fuels, cellulose, latex, cork, lubricants, poisons, scales, bones, hides and rubber. Products include cosmetics, scents, clothing, paper, etc. Some species may serve as tools for the extraction of minerals. Non-Use Value = Source of new materials for industrial use. Harvesting Rubber Lumber Industry – dependence For farmed raw materials (e.g. timber) the same dependence occurs as in agriculture: biological control of soil organisms, nutrient cycling, pollination, soil formation and maintenance, soil fertility and water purification for plant production and all of the above with the addition of food sources for animal production. Wild harvesting is dependent on all the different ecosystem services to sustain the production of the harvested species. All industry is dependent on natural systems for water and air purification and waste treatment. Direct use – bioremediation Bioremediation is the use of biological organisms or their products (e.g. enzymes) to remove or detoxify contaminants from hazardous waste and contaminated soil or water. A species of bacteria can breakdown chlorofluorocarbons (CFCs). Poplar trees (see picture) are used to clean contaminated industrial sites. Bioremediation – dependence Bioremediation depends directly on the ecological services of waste treatment and water purification. Direct use – indicator of ecological change Changes in the levels of biodiversity or individual species ranges may be used to indicate changes in the ecology. Lichen species (see picture) serve as indicators of air quality. Indicator of ecological change – dependence Changes in biodiversity reflect changes in the ecosystem that have changed the functioning of ecosystem services. This use of biodiversity relies directly on the organisms to indicate the condition of the ecosystem of which they are a part. Direct use – ecotourism and recreation People pay to view biodiversity in the natural environment. This is termed ecotourism. Recreation Gardening Camping Hiking and Mountain Biking Sport Fishing Hunting Falconry Ecotourism and recreation – dependence Ecotourism is dependent on all ecological services. Recreational activities such as gardening rely on nutrient cycling, soil fertility and soil formation and maintenance. Camping, hiking and mountain biking in natural areas rely on all ecological services to maintain the aesthetic appeal of the environment. Sports such as fishing, hunting and falconry rely on prey species and the ecological services that sustain them – food sources and habitats which require all the ecological services to maintain them. Direct use – working animals Various ‘wild’ animal species have been trained to aid man. Asian elephants are trained as draught animals. Fishing in China and Southeast Asia Working animals – dependence Farmed working animals require the same inputs as for agriculture. Wild harvesting of animals is dependent on all the ecosystem services to sustain the organisms for harvesting. Direct use – cultural Biodiversity serves as a source of inspiration for art, poetry and literature and influences philosophy, language and religion in many societies. Biodiversity may also supply the medium in which the art is expressed – e.g. canvas for painting and wood for sculptures. Cultural – dependence In as much as any aspect of biodiversity may provide inspiration, cultural diversity is reliant on all ecological services to maintain the source of inspiration. Materials for use in art are the products of industry so the ecological services needed by industry apply – air and water purification and waste treatment as well as supports for production. Products harvested in the wild for cultural purposes rely on all ecosystem services to maintain the product. Direct use – knowledge Each species provides unique information that is lost if the species becomes extinct. Species, species interactions and intact ecosystems are important research areas. Biodiversity provides clues on evolution, past and present. Biodiversity presents insights into how life functions. Knowledge – dependence All ecosystem services are needed to develop understanding of biodiversity. Direct use – live trade Ornamental plants including geophytes, orchids and succulents. Pets Animals for laboratory use, recreation and ecotourism. Live trade – dependence Crassula coccinea Farmed organisms for live trade require the same inputs as for agriculture. Wild harvesting of both plants and animals is dependent on all the ecosystem services to sustain the organisms for harvesting. Problems with monetary values and societal control Market values do not reflect the impacts of use on society and biodiversity. Short term vs. long term benefits. Money may increase faster than the resource reproduces. The rarity of a species increases the monetary value of the product though the costs of obtaining it also increase. The development of products takes time. Ownership. If I do not use this, someone else will. Who benefits? Informal vs. formal markets – political hierarchy. Chapter 1 Biodiversity: what is it? Chapter to 2 The evolution of biodiversity Links other chapters Chapter 3 Biodiversity: why is it important? Chapter 4 Global biodiversity and its decline I hope that you found chapter 3 informative and that you will enjoy chapter 4.