Species survival and carbon retention in commercially exploited tropical rainforest
There have been many recent attempts to place a value on areas of tropical forest. Costanza et al . (1997) attempted to place a value on the whole world’s ecosystem and natural capital. They based their estimate on 17 diﬀerent ecosystem services of 16 biomes and calculated a value of $16-$54 trillion (1012) per year, with an average of $33 trillion. This compares with a global gross national product of $18 trillion. Estimates like this that fall outside the market are hard to calculate, but it is appropriate to consider this vital aspect of value of ecosystem services before looking at a few, in comparison, very minor market-driven approaches to forest conservation. The ecosystems services used by Costanza et al . to make their calculations included gas regulation such as carbon dioxide/oxygen (CO2/O2) balance, as well as climate regulation and control of greenhouse gas. We should not underestimate the value of rainforest for the services as well as for the enormous genetic resources of its biodiversity. There might be more forest standing if an accounting had been made of the value of ecosystem beneﬁts before alteration. Purely on ecosystem service value, a non-use option is often more beneﬁcial than the alternative use to which forest land has been put. The total economic value of ecosystems is discussed well in Pearce et al . (1989) and that of rainforests in Pearce (1990). In the latter, Pearce estimated that the indirect carbon credit due to a single hectare of conserved forest was $1300 in 1990. This was based on a value of $13.00 per tonne of carbon. Many aspects of nature’s services are summed up in Daily (1997).