WHY WE NEED TO CONSERVE BIODIVERSITY
Ecological Reasons
Individual species, populations and ecosystems have evolved over millions of
years into a complex interdependent entities. The ecological arguments for conserving
biodiversity are therefore based on the premise that there is need to preserve
biodiversity in order to maintain life support systems. Two interconnected issues currently of great ecological concern are world-wide deforestation and global climate
change. 
Forests hold large numbers of different species and also play a critical role in regulating
climate.
Deforestation, particularly by
burning, results in great increases in the amount of carbon in the atmosphere. Burning releases huge quantities of carbon
dioxide, one of the main greenhouse gases implicated in
the current global warming, into the atmosphere. Average global temperatures have been showing a steadily
increasing trend. Snow and ice cover have decreased, deep ocean temperatures
have increased and global sea levels have risen by 100 - 200 mm over the last
century. If current trends continue, scientific predictions say that the earth could be
on average 1oC warmer by 2025 and 3oC warmer by 2100.
Although these changes are small, they could have drastic effects. As an example, average
temperature during the last Ice Age was a mere 5oC colder than current
temperature. In
addition to this, rising
sea levels which could drown many major cities, extreme weather
conditions resulting in drought, flooding and hurricanes, together with changes
in the distribution of disease-bearing organisms are all effects of climate
change as previously predicted. Forests also affect rainfall patterns through
transpiration losses and protect the watershed of vast areas. Deforestation
therefore results in local changes in the amount and distribution of rainfall.
It often also results in erosion and loss of soil and often to flooding. These
are only some of the ecological effects of deforestation. The effects described
translate directly into economic effects on human populations.
Economic Reasons
Environmental disasters such as floods, forest
fires and hurricanes indirectly or directly caused by human activities, all
have dire economic consequences for the regions afflicted. Large-scale habitat
and biodiversity losses mean that species with potentially great economic
importance may become extinct before they are even discovered. In the event of extinction, the vast, largely untapped resource of medicines
and useful chemicals contained in wild species may disappear forever. The
wealth of species contained in tropical rain forests may harbour untold numbers
of chemically or medically useful species. Many marine species defend
themselves chemically and this also represents a rich potential source of new
economically important medicines. Additionally, the wild relatives of our
cultivated crop plants provide an invaluable reservoir of genetic material to
aid in the production of new varieties of crops. If all these are lost, then
our crop plants also become more vulnerable to extinction.
Ethical Reasons
It
is very pertinent to ask some salient questions here. For instance, Do we have the right to decide which species
should survive and which should die out? Do we have the right to cause a mass
extinction? Most people would instinctively answer 'No!'. However, we have to
realise that most biodiversity losses are now arising as a result of natural
competition between humans and all other species for limited space and
resources.
Aesthetic Reasons
Most people would agree
that areas of vegetation, with all their attendant life forms, are inherently
more attractive than burnt, scarred landscapes, or acres of concrete and
buildings. Who wouldn't prefer to see butterflies dancing above coloured
flowers, rather than an industrial complex belching smoke? Human well-being is inextricably linked to the
natural world. In the western world, huge numbers of people confined to large
urban areas derive great pleasure from visiting the countryside. The ability to
do so is regarded not so much as a need, but as a right. National governments
must therefore juggle the conflicting requirements for more housing, industry
and higher standards of living with demands for countryside for recreational
purposes.
Follow these links for further reading:
Also
read from this book:
Ayodele,
I A and Lameed, G. A. (1999). Essentials of Biodiversity Management. Powerhouse
Press and Publishers, Ibadan, Nigeria. 73pp.
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