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Notes towards Biodiversity Chapter 3
Introductory/Title Slide (1)
Hello. My name 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 & 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? This chapter looks at
valuing and using biodiversity.
Ways of Assigning Value to Biodiversity (Groombridge 1992, Gaston & Spicer 1998,
Lévêque & Mounolou 2001)
This does not only consider monetary value since monetary value is not easily assigned to
all categories (Groombridge 1992, Gaston & Spicer 1998, Lévêque & Mounolou 2001).
Non-use values are values that do not involve using the resource (Groombridge 1992,
Gaston & Spicer 1998, Lévêque & Mounolou 2001). Biodiversity may be valued for the
use that is made of it either directly or indirectly (Lévêque & Mounolou 2001). Indirect
use values derive from ecosystem functions that are essential to human welfare and are
often termed ‘ecosystem services’ (Groombridge 1992, Gaston & Spicer 1998, Lévêque
& Mounolou 2001, Wikipedia Contributors 2006a, b). Direct use value considers direct
use of biodiversity and transactions with biodiversity (Groombridge 1992). Note that
many direct use values, such as agriculture, production of medicines, industry and live
trade, require space which also affects biodiversity. Direct uses 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 & Lawton
1996, Gaston & Spicer 1998, Wikipedia Contributors 2006a).
Non-use Value
Option value places value on the potential benefits from future use of a resource
(Groombridge 1992, Gaston & Spicer 1998, Lévêque & Mounolou 2001). Bequest value
considers the potential benefits to future generations from the use of a resource (Gaston
& Spicer 1998, Lévêque & Mounolou 2001). 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 & Lawton 1996, Gaston & Spicer 1998, Lévêque &
Mounolou 2001). Aesthetic value considers the pleasure we take in the appearance of
organisms and natural ecosystems (Kunin & Lawton 1996, Miller 2002).
Indirect Use Value
Ecosystem services are strongly interlinked. The use of these systems is usually not
sufficiently considered which is why we have problems with pollution. References
giving indirect use values include Groombridge (1992), Kunin & Lawton (1996), Patrick
(1997), Gaston & Spicer (1998), Lévêque & Mounolou (2001), Wikipedia Contributors
(2006a, b, c)
Indicator of Environmental Resources
Direct Use – Indicator of Environmental Resources
Certain plant species serve as reliable indicators of desired environmental conditions e.g.
Eriocephalus africanus indicated fertile soil suitable for agriculture in the Swartland
(pers. comm. Mr. M. Gregor 2003). The picture shows Eriocephalus africanus. 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 refers to the reliance on indirect use services for 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 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 the species in that area.
Direct Use - Food Production
Most of what we eat is produced by living organisms – either through agriculture or
harvesting from the wild (Groombridge 1992, Kunin & Lawton 1996). Subsistence
farmers particularly benefit from biodiversity by harvesting the natural veld (Kunin &
Lawton 1996, Lévêque & Mounolou 2001). Food additives such as spices may also be
natural products (Nations 1988, Pietra 2002). Aids to food production such as pesticides,
insecticides, fungicides & fertilizers may be derived from biological sources (Plotkin
1988, Groombridge 1992, Kunin & Lawton 1996, Pietra 2002). Genetic improvement of
domesticated species is achieved by crossing them with wild species or by gene transfer
(Kunin & Lawton 1996, Lovejoy 1997, Lévêque & 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). 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 (Kunin & Lawton 1996,
Lévêque & Mounolou 2001). Wild harvesting is dependent on all the different ecosystem
services to sustain the production of the harvested species. Agriculture is dependent on
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 (Patrick 1997) for animal production
(Wikipedia Contributors 2006a).
Biological Control
Direct Use – Biological Control
The direct use of a natural enemy to control a pest organism (Kunin & Lawton 1996).
The picture shows Uromycladium tepperianum on 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 & Lawton 1996, Lévêque
& Mounolou 2001, Pietra 2002). Animals are used for product testing e.g. armadillos
(Dasypus novemcinctus) have been used to study leprosy (Nations 1988, Kunin &
Lawton 1996). Biodiversity offers abundant potential for new medicines (Farnsworth
1988, Kunin & Lawton 1996, Lévêque & Mounolou 2001).
Medicine – Dependence
Animal testing of medicines requires food for the animals. Wild harvesting for
traditional or other use is dependent on all the different ecosystem services to sustain the
production of the harvested species. Chemical production of medicines is dependent on
the water and air purification and waste treatment services of ecosystems.
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 & Lawton 1996, Patrick 1997,
Lévêque & 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 of biodiversity see
Plotkin (1988), Groombridge (1992), Pietra (2002) and Wikipedia Contributors (2006a).
Some plants may serve as tools for the extraction of minerals (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). Non-Use Value = 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 (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 is a hybrid poplar tree.
Bioremediation – Dependence
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 (Lovejoy 1997) e.g. lichen species serve as indicators of air
quality (Monaci et al. 1997, Vokou et al. 1999). 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 balance
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.
Live Trade
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 posing a major threat to the
survival of some species in the wild (Groombridge 1992, Kunin & Lawton 1996).
As with ornamental plants, most pets were originally taken from the wild. Some species
were domesticated. The existence of certain species in the wild is threatened because of
continued harvesting from the wild (Groombridge 1992, Kunin & Lawton 1996).
Animals for laboratory use (Kunin & Lawton 1996), recreation and ecotourism (Van der
Waal & Dekker 2000) are traded with.
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.
Direct Use – Ecotourism and Recreation
People pay to view biodiversity in the natural environment. This is termed ecotourism
(Lévêque & Mounolou 2001). Ecotourism is a growing industry that needs to be
controlled so that it does not harm the resources it is using (Gaston & Spicer 1998,
Lévêque & Mounolou 2001).
There are various forms of recreational use of biodiversity. It should be noted that some
need not take place in the 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 hunting, fishing (Groombridge 1992, Kunin &
Lawton 1996) and falconry (Groombridge 1992) involve natural or disturbed
environments.
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 has 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.
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 2006d) 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.
Cultural
Direct Use – Cultural
Biodiversity serves as a source of inspiration for art, poetry and literature and influences
philosophy, language and religion in many societies (Groombridge 1992, Lévêque &
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.
Knowledge
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 &
Lawton 1996). Biodiversity provides clues on evolution, past and present (Wikipedia
Contributors 2006a). Biodiversity presents insights into how life functions (Wikipedia
Contributors 2006a).
Knowledge – Dependence
All ecosystem services are needed to develop understanding of biodiversity.
Problems with Monetary Values for Biodiversity
Market values do not reflect the impacts of use on society and biodiversity (Perrings
1995, Lévêque & 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 & 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 & 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).
Ownership. 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). Cumulatively, shared resources are likely to be over utilized because
each individual is considering his/her own interests not the collective interest. To prevent
this, regulations need to be established and enforced (Miller 2002). Who benefits?
Informal vs. formal markets – political hierarchy (Kunin & Lawton 1996, Lévêque &
Mounolou 2001). For example, 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 & Lawton 1996, Lévêque &
Mounolou 2001).
Last slide
I hope that you found chapter 3 informative and that you will enjoy chapter 4.