Notes Towards Biodiversity Chapter 3

Notes towards Biodiversity Chapter 3

Introductory/Title slide (1)

Hello. This is Gwen Raitt. I will be presenting this chapter on the importance of 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 (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 (Groombridge 1992, Gaston and Spicer 1998, Lévêque and Mounolou 2001)

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

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

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).

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 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 (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

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).

Biological control

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

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. 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.

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 (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.

Bioremediation

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.

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.

Direct use – ecotourism and recreation

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).