Biodiversity: why is it important? Gwen Raitt Biodiversity and Conservation Biology Department 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? The question asked on the title slide assumes that biodiversity is important, is it? Biodiversity has been subject to huge losses (mass extinctions) before (Groombridge 1992). 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 and Spicer 1998). “What sort of world are we prepared to pay to live in?” (p. 87 Gaston and Spicer 1998). If biodiversity is important, how do we use it sustainably? This chapter looks at valuing and using biodiversity.

Ways of assigning value to biodiversity This does not only consider monetary value. Non-use Values Use Values Indirect Direct Intrinsic Value This does not only consider monetary value since monetary value is not easily assigned to all categories of value (Groombridge 1992, Gaston and Spicer 1998, Lévêque and Mounolou 2001). Non-use values of biodiversity are values that do not involve using or depleting the resource as opposed to use values which generally involve the depletion of the resource (Groombridge 1992, Gaston and Spicer 1998, Lévêque and Mounolou 2001). Biodiversity may be valued for the use that is made of it either indirectly or directly (Lévêque and Mounolou 2001). Indirect use values derive from ecosystem functions that are essential to human welfare and are often termed ‘ecosystem services’ (Groombridge 1992, Gaston and Spicer 1998, Lévêque and Mounolou 2001, Wikipedia Contributors 2006a, b). Direct use values consider the direct use of biodiversity and transactions with biodiversity (Groombridge 1992). Note that many direct use values (such as agriculture, the production of medicines, industry and live trade) require space which also affects biodiversity. In this chapter, direct uses of biodiversity will be described and then linked to the indirect uses on which they depend. Intrinsic Value refers to the inherent value of any living organism without reference to humanity (Kunin and Lawton 1996, Gaston and Spicer 1998, Wikipedia Contributors 2006a). Additional Notes Extract from Wikipedia (2006A) ~ http://en.wikipedia.org/wiki/. “Deep ecology is a recent philosophy or ecosophy based on a shift away from the anthropocentric bias of established environmental and green movements. The philosophy is marked by a new interpretation of ‘self’ which de-emphasises the rationalistic duality between the human organism and its environment, thus allowing emphasis to be placed on the intrinsic value of other species, systems and processes in nature. This position leads to an ecocentric system of environmental ethics. Deep ecology describes itself as ‘deep’ because it asks complex and spiritual questions about the role of human life in the ecosphere. Proponents of deep ecology believe that the world does not exist as a resource to be freely exploited by humans. The ethics of deep ecology holds that a whole system is superior to any of its parts. They offer an eight-tier platform to elucidate their claims: The well-being and flourishing of human and nonhuman life on Earth have value in themselves (synonyms: intrinsic value, inherent value). These values are independent of the usefulness of the nonhuman world for human purposes. Richness and diversity of life forms contribute to the realisation of these values and are also values in themselves. Humans have no right to reduce this richness and diversity except to satisfy vital human needs. The flourishing of human life and cultures is compatible with a substantial decrease of the human population. The flourishing of nonhuman life requires such a decrease. Present human interference with the nonhuman world is excessive, and the situation is rapidly worsening. Policies must therefore be changed. These policies affect basic economic, technological, and ideological structures. The resulting state of affairs will be deeply different from the present. The ideological change is mainly that of appreciating life quality (dwelling in situations of inherent value) rather than adhering to an increasingly higher standard of living. There will be a profound awareness of the difference between big and great. Those who subscribe to the foregoing points have an obligation directly or indirectly to try to implement the necessary changes.”

Non-use values Values based on potential: Option Value Bequest Value Values based on human awareness and perceptions: Existence Value Aesthetic Value Non-use values consider the potential benefits not yet realised and the benefits derived from human awareness/perceptions of the world. There are two forms of value that consider potential. Option value places value on the potential benefits from future use of a resource (Groombridge 1992, Gaston and Spicer 1998, Lévêque and Mounolou 2001). Bequest value considers the potential benefits to future generations from the use of a resource (Gaston and Spicer 1998, Lévêque and Mounolou 2001). There are two types of value related to human awareness and human perceptions. Existence value refers to the value people attach to knowing that the resource exists even though they have no expectation of seeing it (Groombridge 1992, Kunin and Lawton 1996, Gaston and Spicer 1998, Lévêque and Mounolou 2001). Aesthetic value considers the pleasure we take in the appearance of organisms and natural ecosystems (Kunin and Lawton 1996, Miller 2002).

Indirect use values Nutrient Cycling Food Decom-position Waste Treatment + Abiotic = Habitat Gas Re-gulation Carbon Se-questration Trophic Levels Soil Fertility Air Puri-fication Climate Regulation Biological Control Soil Forma-tion & Main-tenance Natural Organisms form Ecosystems Ecosystem services are strongly interlinked and consequently difficult to separate as can be seen from the diagram. As a result, the diagram shown is probably incomplete. The use of these ecosystem services is usually not sufficiently considered, which is why we have problems with pollution. References giving indirect use values include Groombridge (1992), Kunin and Lawton (1996), Patrick (1997), Gaston and Spicer (1998), Lévêque and Mounolou (2001), Wikipedia Contributors (2006a, b, c). Pollination Disturbance Control Water Re-gulation Erosion Control Water Pu-rification

Indicator of environmental resources 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. – dependence and effect Indicator of environmental resources 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 – 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 e.g. kapokbos (wild rosemary - Eriocephalus africanus) indicated fertile soil suitable for agriculture in the Swartland (pers. comm. Mr. M. Gregor 2003). The picture shows wild rosemary, Eriocephalus africanus. A further illustration is that some plant species have affinities to certain metals. Berkheya coddii may be endemic to nickeliferous serpentine soils (Morrey et al. 1989). Indicator of environmental resources – dependence and effect Dependence, as used here, refers to the reliance on indirect use services to sustain the direct use. The use of plants as indicators of environmental resources is dependent on autecological knowledge of the plant species. Such knowledge depends on observations/studies of the species in its natural habitat which means that it is dependent on 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. Most of what we eat is produced by living organisms – either through agriculture or through harvesting from the wild (Groombridge 1992, Kunin and Lawton 1996). Subsistence farmers particularly benefit from biodiversity by harvesting the natural veld (Kunin and Lawton 1996, Lévêque and Mounolou 2001). Natural products also contribute to other areas of food production. Food additives such as spices may also be natural products (Nations 1988, Pietra 2002). Aids to food production such as pesticides, insecticides, fungicides and fertilisers may be derived from biological sources (Plotkin 1988, Groombridge 1992, Kunin and Lawton 1996, Pietra 2002). Genetic improvement of domesticated species is achieved by crossing them with wild species or by gene transfer (Kunin and Lawton 1996, Lovejoy 1997, Lévêque and Mounolou 2001). The process of cross breeding takes time, e.g. the value of a wild tomato species was only visible about 17 years after its discovery (Iltis 1988). Biotechnology will probably decrease the time needed to derive a benefit from wild species. The related non-use value (a form of option value) is that new species for agricultural use may be found in nature. More variety would help to reduce our dependence on a limited number of species (Plotkin 1988).

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. 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. Cropland uses space. As the picture shows, food production requires space, displacing the natural biodiversity. The survival of species harvested from the wild is threatened by overexploitation (Kunin and Lawton 1996, Lévêque and Mounolou 2001). Wild harvesting is dependent on all the different ecosystem services to sustain the production of the harvested species. 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 (Patrick 1997), 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 (Patrick 1997, Wikipedia Contributors 2006a).

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. – dependence Biological control 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 – biological control The direct use of a natural enemy to control a pest organism is known as biological control (Kunin and Lawton 1996). The picture shows the fungus Uromycladium tepperianum on Port Jackson (Acacia saligna). This is an example of biological control in South Africa. 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 com-mercial production of bio-diversity derived medicines are important sources of medications. Traditional medicines (see picture). Animals for product testing Non-Use Value = Source of new medicines Many medicines were identified from various organisms e.g. aspirin, now synthetically produced, was found in the willow tree (Salix alba) (Lovejoy 1997, Pietra 2002). Commercial production of organisms for the extraction of medicines and direct commercial production of biodiversity derived medicines are important sources of medications (Farnsworth 1988, Pietra 2002, Wikipedia 2006a). Many people cannot afford modern medications so they rely on traditional medicines. These medicines are extracts of organisms taken from the wild (Plotkin 1988, Kunin and Lawton 1996, Lévêque and Mounolou 2001, Pietra 2002). Animals are used for commercial product testing e.g. armadillos (Dasypus novemcinctus) have been used to study leprosy (Nations 1988, Kunin and Lawton 1996). A non-use value related to the direct medical use of biodiversity is that biodiversity offers abundant potential for new medicines (Farnsworth 1988, Kunin and Lawton 1996, Lévêque and Mounolou 2001).

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. 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. The use of animal testing of medicines requires a supply of food for the animals which means that the ecosystem services required to produce the food are also used. 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 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 (Nations 1988, Plotkin 1988, Groombridge 1992, Kunin and Lawton 1996, Patrick 1997, Lévêque and Mounolou 2001, Wikipedia Contributors 2006a). Products include cosmetics, scents, clothing, paper, etc. (Plotkin 1988, Pietra 2002, Wikipedia Contributors 2006a). For more information on direct industrial use and depletion of biodiversity see Plotkin (1988), Groombridge (1992), Pietra (2002) and Wikipedia Contributors (2006a). Some species (e.g. microbial species and plant species) may serve as tools for the extraction of minerals. This is known as biomining (ucbiotech.org undated). If the species used are plants, the term used is phytomining. A crop of metal-hyperaccumulators is grown then the biomass is harvested and burnt to provide bio-ore. Berkheya coddii (a South African species) is an efficient Ni (nickel) hyperaccumulator (Anderson et al. 1999). Berkheya coddii leaves have significantly higher concentrations of Ni (nickel) than either the soil or bedrock on which it grows (Mesjasz-Przybylowicz et al. 2004). A non-use value related to the direct industrial use of biodiversity is that biodiversity offers a source of new materials for industrial use (Nations 1988, Plotkin 1988).

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. 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. – dependence 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 (Miller 2002, Cunningham et al. 2003). A species of bacteria found in the Potomac River’s sediments can breakdown chlorofluorocarbons (CFCs) (Lovejoy 1997). Poplar trees (Populus spp. and hybrids) are used to clean contaminated industrial sites (Miller 2002). The picture shows a hybrid poplar tree. Bioremediation – dependence Bioremediation depends directly on the ecological services of waste treatment and water purification in an unnatural setting. Bioremediation Bioremediation depends directly on the ecological services of waste treatment and water purification.

Indicator of ecological change 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. – dependence Indicator of ecological change Direct use – indicator of ecological change Changes in the levels of biodiversity or individual species ranges may be used to indicate changes in the state of the ecosystem (Lovejoy 1997) e.g. lichen species (some are pictured) serve as indicators of air quality (Monaci et al. 1997, Vokou et al. 1999). Such indicator species are known as bioindicators (Wikipedia Contributors 2006d). In some cases, it may be possible to isolate the causes of the disturbance and remove them. 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. 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 People pay to view biodiversity in the natural environment. This is termed ecotourism (Lévêque and Mounolou 2001). Ecotourism is a growing industry that needs to be controlled so that it does not harm the resources it is using (Gaston and Spicer 1998, Lévêque and Mounolou 2001). There are various forms of recreational use of biodiversity. It should be noted that some need not take place in a natural setting. Gardening is recreational (for some people) but not natural. Camping, hiking (Miller 2002) and sometimes mountain biking may be done in natural environments. Sports such as fishing, hunting and falconry (Groombridge 1992, Kunin and Lawton 1996) involve natural or disturbed environments. Additional Notes Extract from Miller (2002) pp. 562, A11: “Ideally, ecotourism (1) should not cause ecological damage, (2) should provide income for local people to motivate them to preserve wildlife, and (3) should provide funds for the purchase and maintenance of wildlife preserves and conservation programs. However, most nature tourism does not meet these goals and excessive and unregulated ecotourism can destroy or degrade fragile areas and promote premature species extinction.” “Evaluating Ecotours Before embarking on an ecotour, seek answers in writing to the following questions: What precautions are taken to reduce the tour’s impact on local ecosystems? How much time is spent in the field, versus in the city or traveling in a vehicle? What happens to the tour’s garbage? What percentage of the people involved in planning, organizing, and guiding tours are local? Are the guides trained naturalists? Will you stay in locally owned hotels or other facilities, or will you be staying in accommodations owned by national or international companies? Does the tour operation respect local customs and cultures? If so, how? What percentage of the tour’s gross income goes into the salaries and businesses of local residents? What percentage of the tour’s gross income does the tour company donate to local conservation and social projects?”

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. Ecotourism is dependent on all ecological services. Recreational activities such as gardening rely on the same ecosystem services as agriculture, including 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. The picture shows hiking trails on Table Mountain.

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 – dependence Working animals Direct use – working animals Various ‘wild’ animal species have been trained to aid man (Groombridge 1992), e.g. Asian elephants (also known as Indian elephants, Elephas maximus) are trained as draught animals (Groombridge 1992, Wikipedia Contributors 2006e) and the fishing industry in China and Southeast Asia makes use of otters (Lutra spp.) and cormorants (Phalacrocorax spp.) (Groombridge 1992). Working animals – dependence Farmed working animals require the same inputs as for agriculture i.e. biological control of soil organisms, nutrient cycling, pollination, soil formation and maintenance, soil fertility and water purification and food sources. Wild harvesting of animals is dependent on all the ecosystem services to sustain the organisms for harvesting. 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 – dependence 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. – dependence Cultural 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 – cultural Biodiversity serves as a source of inspiration for art, poetry and literature (which may be a direct use value or a non-use value in the form of aesthetic appreciation) and influences philosophy, language and religion in many societies (Groombridge 1992, Lévêque and Mounolou 2001). 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 ecosystems services to maintain the product.

Direct use – knowledge – dependence 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. 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 (Kunin and Lawton 1996). Biodiversity provides clues on evolution, past and present and biodiversity presents insights into how life functions (Wikipedia Contributors 2006a). Knowledge – dependence All ecosystem services are needed to develop an understanding of biodiversity. – dependence Knowledge All ecosystem services are needed to develop understanding of biodiversity.

Direct use – live trade – dependence Live trade Ornamental plants including geophytes, orchids and succulents. Pets Animals for laboratory use, recreation and ecotourism. – dependence Live trade Crassula coccinea Direct use – live trade Ornamental plants including geophytes, orchids and succulents were originally taken from the wild. Some species are still harvested from the wild. This poses a major threat to the survival of certain species in the wild (Groombridge 1992, Kunin and Lawton 1996). Plants are also traded for cultural and medicinal purposes. As with plants, animals were originally taken from the wild as beasts of burden, food and pets. Some species were domesticated. The existence of certain species in the wild is threatened because of continued harvesting from the wild (Groombridge 1992, Kunin and Lawton 1996). Animals are traded for laboratory use, recreation and ecotourism (Kunin and Lawton 1996, Van der Waal and Dekker 2000). Not all live trade is legal, which makes controlling it difficult (Brooks et al. 2006). Live trade – dependence Farmed organisms for live trade require the same inputs as for agriculture, i.e. 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 of both plants and animals for live trade is dependent on all the ecosystem services to sustain the organisms for harvesting. 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. Market values do not reflect the impacts of use on society and biodiversity (Perrings 1995, Lévêque and Mounolou 2001), e.g. the market value of timber extracted from tropical forests does not reflect the loss of ecological services or the loss of forest products to the locals (Lévêque and Mounolou 2001). Short term vs. long term benefits. The long term benefits of ecosystem services are difficult to quantify monetarily and short term monetary gain is appealing especially as money may increase faster than the resource reproduces (Dobson 1996, Kunin and Lawton 1996). The rarity of a species increases the monetary value of the product though the costs of obtaining it also increase (Dobson 1996). The development of new biodiversity products takes time (Iltis 1988). The ownership of resources affects their use. Cumulatively, shared resources are likely to be over utilised because each individual is considering his/her own interests not the collective interest (Miller 2002). Someone else will use this if I do not (Dobson 1996, Miller 2002). The resource is renewable, “the little bit that I use or pollute” will not be enough to matter (p. 12 Miller 2002). To prevent this, regulations need to be established and enforced (Miller 2002). Who benefits? Informal vs. formal markets – political hierarchy (Kunin and Lawton 1996, Lévêque and Mounolou 2001), e.g. a piece of tropical forest will supply the locals with various products which they will use and trade locally. The timber from the same piece of forest will be sold internationally providing foreign exchange, the benefits of which are reflected at a national level, usually without any benefits to the locals. Though the timber income is once off and considerably less than the cumulative local income, the probability is that the national benefit will outweigh the local benefit should the government be approached concerning the timber (Kunin and Lawton 1996, Lévêque and Mounolou 2001).

Links to other chapters Chapter 1 Biodiversity: what is it? Chapter 2 The evolution of biodiversity Chapter 3 Biodiversity: why is it important? Chapter 4 Global biodiversity and its decline Links to other chapters I hope that you found chapter 3 informative and that you will enjoy chapter 4. The picture shows a view over the Hluhluwe-Umfolozi Game Reserve. I hope that you found chapter 3 informative and that you will enjoy chapter 4.