Jumat, 01 Juli 2016

#149 The need to maintain biodiversity

For some people, the safety of biodiversity is simply a moral or ethical issue. For others it may be for ecological reasons, aesthetic reasons, social and commercial reasons or for other services.







Ecological reasons

  • the higher the diversity of an ecosystem, the less likely it is to be unbalanced by changes in conditions or threats such as pollution
  • ecosystems are of direct value to humans
                  e.g.: - antibiotics from fungi, bacteria
                          - anti-cancer drugs isolated from plants
Aesthetic reasons
  • people gain pleasure from studying or just appreciating the natural work (inspiration to artists, poets, photographers,...)
  • ecotourism: wildlife = source of income --> provides employment; contributes to economies

Social and commercial reasons
  • wild plants species that are resistant to large numbers of disease of rice known as bacterial blight --> interbreed with cultivated rice (crop plants don't hae much genetic diversity as their wild relatives, because it has been lost by selective breeding for uniform, high-yielding crops)
  • microorganisms = source of useful products
                  e.g.: Taq polymerase used for PCR in forensic and DNA analysis

Other services
  • forests absorb CO2 --> lowers the effect of high CO2 concentration in the atmosphere
  • organic waste added in water gets broken down by mircroorganisms
  • transpiration of plants: contribute to the water cycle - provides water for drinking and irrigation
  • termites, ants, fungi, bacteria recycle elements (C,H,O,N,...)




  Syllabus 2016-2018

18.3 Conservation

Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels. 

 It is important to conserve ecosystems as well as individual species.

a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b) 

b) discuss the reasons for the need to maintain biodiversity 

c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks 

d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals 

e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species 

f) use examples to explain the reasons for controlling alien species 

g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation 

h) outline how degraded habitats may be restored with reference to local or regional examples