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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.”. Level of Biodiversity. 3 level of biodiversity are considered:
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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.” BBA3(Gajaseni)
Level of Biodiversity 3 level of biodiversity are considered: 1. Genetics diversity 2. Species diversity 3. Ecosystem diversity BBA3(Gajaseni)
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. BBA3(Gajaseni)
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. BBA3(Gajaseni)
But, these species currently used are only a tiny fraction of total species diversity. ???? BBA3(Gajaseni)
Species diversity values • Species have use values such as: • raw materials • foods • fiber plants • medicines • bioenergy • natural pesticides • scientific and educational materials BBA3(Gajaseni)
Table 18-2 Modern Drugs from Traditional Medicines. These Drugs Were Discovered by Traditional Healers and Developed by Pharmaceutical Researec. BBA3(Gajaseni)
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. BBA3(Gajaseni)
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. BBA3(Gajaseni)
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) BBA3(Gajaseni)
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. BBA3(Gajaseni)
What is different between deforestation, reforestation and afforestation? BBA3(Gajaseni)
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. BBA3(Gajaseni)
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). BBA3(Gajaseni)
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 BBA3(Gajaseni)
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 BBA3(Gajaseni)
