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October 27, 2006

Which species should we preserve?

Earlier this year I asked my students to write a short essay to answer the question, which species should we preserve? I explicitly told them not to argue that we should preserve all species, as many species as possible, or no species at all, and we later discussed why any of those answers would lead nowhere. A few weeks ago George M. Woodwell argued that we should preserve all species. Now Bradley J. Cardinale and collaborators state "that a precautionary approach to preserving as much biodiversity as possible is warranted." And they do that after finding evidence that biomass production in local ecosystems does not decrease when all but the single most productive species disappear. I will keep my eyes open to see who argues that we should preserve no species.

3 comments:

  1. I would be interested in what background reading you gave your students: I am embarking on an investigation of this question, to see if (1) evolutionary distinctiveness has traction as one (of several) currencies and (2) how these currencies can be made fungible. This necessitates a discussion of 'value' more generally.

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  2. In the summary of the paper I linked to in my post Bradley J. Cardinale and coauthors state that "the standing stock of, and resource depletion by, the most species-rich polyculture tends to be no different from that of the single most productive species used in an experiment." In the discussion they say that "theory predicts that diverse polycultures will produce more biomass and capture a greater fraction of limited resources than even the 'best' species monoculture. The balance of evidence from experiments does not seem to support this."

    I don't know whether their results and conclusions are correct or not. But I do know that arguing that we should preserve "as much biodiversity as possible" is useless. What is "possible?"

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  3. "Your HTML tags don't show in blogger beta." Oops, I have no clue about that. Should I fix anything?

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