Loss of Biodiversity Part II: Does the extinction of species really matter?
You’ve probably heard several times that we are at the brink of the largest massive extinction of species since the disappearance of dinosaurs and that we are experiencing the greatest threat to biodiversity. We’re losing about 3 species an hour, or about 50,000 species a year.
Does extinction of species really matter?
I’ve met a few people to whom losing the giant panda in China, or the orangutans in Borneo, or the “unknown and undiscovered” creepy crawlies on the forest floor of a tropical rainforest, or a fish species in the ocean deep, don’t really matter..after all, species extinction is a routine part and parcel of evolution. Agreed, but what is unprecedented in the 3 ½ billion years of so of evolution is the rapidity of the rate of extinction, almost entirely due to human activities, and this rapidity of extinction is bound to have repercussions.
Interdependence of species
Species are interdependent in many ways and don’t live in isolation. An extreme form of vulnerability is a one-to-one dependency, where one species is entirely and exclusively dependent on the other for survival .
Can you recognise this? This is a fruiting fig tree. There are about 800 species of fig trees all over the world, but what is an absolute ecological marvel is that each species of fig tree is pollinated by a unique species of wasp, tiny ones about 2mm only! If for some reason, the species of wasp, or the fig tree species were to be affected, the other dependant species would also disappear.
Nature abounds in such interdependencies, and if any one species disappears, it causes a chain reaction in which other species of animals, birds, insects and plants are also affected. When such links are cut, eventually ecosystems collapse, and humans who are dependent on them for food, for fibre and products will also be severely affected.
Biodiversity holds immense pharmaceutical interests, and this is one of the main economic reasons why it is so important. Only 1% of the rainforests have been studied. As someone said, losing biodiversity is like burning down an ancient library after reading only 1% of the books.
What is the value of Biodiversity and Nature’s services?
This is a really interesting concept because we know the value of economic goods, or for example, a country’s output of goods and services. Like many things of genuine value to society, like happiness, a homemaker’s contribution to the family, or for the wonderful services that Nature provides, there is no economic value.
However, Costanza et al in 1997 impute an economic value of all of Nature’s services and it worked out to be US $33 trillion per year, much more than the value of the gross national products of all nations at the time of US $18 trillion. That really tells us something, doesn’t it!
Dr. Gretchen Daily in her famous study lists the following “ecosystem services” which contribute to to human welfare:
• purification of air and water
• mitigation of floods and droughts
• detoxification and decomposition of wastes
• generation and renewal of soil and fertility
• pollination of crops and natural vegetation
• control of the vast majority of potential agricultural pests
• dispersal of seeds and translocation of nutrients
• sources of crop varieties, medicines and industrial enterprise
• protection from the sun’s harmful ultraviolet rays
• partial stabilization of climate
• moderation of temperature extremes and the force of wind and waves
• support of diverse human cultures
• provision of aesthetic beauty and intellectual stimulation that lift the human spirit
To this list we could add an important function in an era of global warming, the “storage of carbon” as ecosystems remove carbon from the atmosphere, release oxygen, and store carbon in biomass (such as wood)
Extinction isn’t just a loss for science and scientists; it’s a real loss for all of us. Yet wittingly or unwittingly, we are steadily impoverishing a rich and varied form of life with our economic activities. What a dull and monotonous world it would be indeed, if all we had left to show of the planet to our descendants were a few predictable species of plant and animals in monoculture plantations and animal farms, craftily selected by us humans to serve our need and greed…a planet with no surprises, nothing left to discover and marvel.
Short URL: http://www.ecowalkthetalk.com/blog/?p=100
Subscribe by RSS Subscribe by email
|Connect with us on|