* Astronomy

Blobrana · L

RE: Ecosystems

Blobrana · L

Google's algorithm for ranking web pages can be adapted to determine which species are critical for sustaining ecosystems, say researchers.
According to a paper in PLoS Computational Biology, "PageRank" can be applied to the study of food webs.
These are the complex networks of who eats whom in an ecosystem.
The scientists say their version of PageRank could be a simple way of working out which extinctions would lead to ecosystem collapse.

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Blobrana · L

Inventories of living and dead organisms could serve as a relatively fast, simple and inexpensive preliminary means of assessing human impact on ecosystems. The University of Chicagos Susan Kidwell explains how measuring the degree of live-dead mismatch could be used as an ecological tool in the Oct. 26 early online edition of the Proceedings of the National Academy of Sciences.

We affect ecosystems in many different ways, but the effects of our actions are hard to pin down because we rarely have scientific data from before the onset of those impacts - Susan Kidwell, the William Rainey Harper Professor in Geophysical Sciences at Chicago.

Detailed ecological data, when they exist at all, often go back no more than 50 years. But scientists would prefer a deeper historical perspective that covers centuries or even a millennium. Live-dead studies can provide some of the needed perspective, according to Kidwell. In these studies, scientists collect data on the living organisms and the skeletal remains found in a specific ecosystem, then evaluate how closely they match.

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