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Biodiversity

McNeely (1988) defined

“Biodiversity is a comprehensive word for the degree of nature’s variety, including both the number and frequency of ecosystem, species and genes in a given assemblage.”

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Level of Biodiversity

• 3 level of biodiversity are considered:

1. Genetics diversity

2. Species diversity

3. Ecosystem diversity

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• 1.4 million species of flora, fauna and microbes have been examined, named and classified.

• Scientists estimate total species diversity 5-30 million species on earth that have not yet been explored.

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Value of Biodiversity

• Biodiversity at all levels contribute and sustain human life and economic activity

• Biodiversity provides ‘biological wealth’

• Species is directly useful to humans, such as food, medicines, fuel, construction materials, and other utilitarian needs.

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But, these species currently used are only a tiny fraction of

total species diversity.

????

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Species diversity values

• Species have use values such as:– raw materials– foods– fiber plants– medicines– bioenergy– natural pesticides– scientific and educational materials

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-182Table Modern Drugs from Traditional Medici

nes. These DrugsWere Discovered by Traditional Healers and Developed by

Pharmaceutical Researec.

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Genetic diversity value

• It is focusing on:– Genetic resources– Commercial products (Agricultural or

pharmaceutical products)– Genetic modification– Genetic engineering

• It is difficult to provide the monetary values.

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Ecosystem diversity value

• It provides lots of services to the whole earth which might be valued relative to its services:

– food production

– energy supply

– water supply

– aesthetics

– etc.

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Biodiversity in Thailand

• In 1961, forest covered more than half of Thailand’s land area.

• The forest cover dropped to 28% after 3 decades.

• Thailand located between the Indo-Malayan and Asian continental biogeographical region.

• Thailand has been rich in biodiversity (genetics, species and ecosystems)

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Biodiversity loss in Thailand

• The significant biodiversity loss is related to the loss of: – Terrestrial forests– Coastal mangrove forests– wetlands

• Even 16% of total land area of the country will be declared as ‘Protected area’ but still have pressure of deforestation.

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• What is different between deforestation, reforestatio

n and afforestation?

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• Deforestation = the act/process of changing forest land to non-forest land.

• Reforestation = the act/process of changing previously deforested lands back to forest land.

• Afforestation = the act/process of creating forest land where it ‘historically’ did not exist.

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• Reforestation programs are being implemented but the rate of reforestation is far below the deforestation rate.

• Deforestation rate has slowed from 0.9% per year before 1989 to 0.4% per year just after ban logging.

• Thailand lost >50%of mangrove forest between 1961 (372,000 ha) and 1993 (168,000 ha).

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• The decline of mangrove is due to the combined effect of aquaculture (32%), timber and firewood clear-felling, salt ponds, etc.

• Marine biodiversity (sea grass and coral reefs) are affected by...– Household & industrial wastes– Sedimentation

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• Fisheries catch increases at a rate of 4.3% per year.

• Fishing yields decline because of – over-harvesting of marine fisheries

about tenfold.

– over-capitalisation of fisheries sector stimulated by open access

– poor enforcement of regulations

– input subsidies on fuel and fishing gear

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