Wednesday, December 08, 2004

False Alarms (but good concepts)

Posted by Trent Walters at 11:25 PM
The November 12 issue of Science promised a review of "Biodiversity Conservation and the Eradication of Poverty." At least I thought they might have plans on how this might be done. Nay. They note that often the two are considered at odds (consider, famously, protecting the diverse life of Amazon rainforests vs. feeding Brazilian families). Maybe eco-tourism (however many families that may employ). My brief brain storm included native botanists procuring and documenting new species of plant life. Continue at will, as Geoff might say. You thought that this news item went away? Burning rainforests makes it one of the world's largest polluters, not to mention the loss of a huge sink for carbon and life varieties (not unrelated chemically, but studied separately). Maybe someone might come up with a novel and genius concept in fiction.

The same issue gave a perspective on "How Extinction Patterns Affect Ecosystems." A cool illustration showed the basics:

Traits that increase up the food web (meaning plants->herbivores->carnivores->top dog):
Vulnerability to habitat fragmentation
Home Range Area
Body Size

Traits that decrease going up the food web:
Vulnerability to Stress
Ability to adapt
Species richness (insurance [that the species will survive])

Anyway the article writer goes on to point out two reports in the issue that seem to demonstrate that "most real extinction events are nonrandom [i.e. something caused it] ... [because] impact of nonrandom species extinctions on ecosystems is markedly different from that predicted by scenarios where extinctions are random." Two totally different eco-systems are analyzed in these studies: terrestrial and marine. I didn't quite follow the greater meaning of the terrestrial study in which a new weed was introduced into a population of plants, but one essense of the marine study is that when you lose the keystone species (the largest number of species at the bottom of the food web in an ecosystem, which in this case was the brittlestar), the effect on the ecosystem is significant compared to the loss of a less populous species. I don't think that's really news, though.