Sunday, February 20, 2011

The ecology crisis and shrinking biodiversity in a warming world

I'm putting together a few links on ecology and biodiversity. Most nature lovers will have observed changes in their local flora and fauna in recent years. There will be many more changes over coming years as species are affected by the altered atmosphere and the warming earth, which will have multiple and cascading effects affecting food webs and local habitats. Here is some further reading on the subject.

Jeff Harvey responded to Eli Rabett's request for reading material and suggested places to start learning about the biodiversity crisis. Dr Harvey recommends the Millenium Assessment Reports as a starting point.

Bart has posted some useful links on the topic, and the thread includes some excellent posts by Jeff Harvey and Bernard J, though the thread got hijacked further along the way. There is discussion of the Amazon, on inter-relationships and how broken links will have a cascading effect; and the notion of 'extinction debt' and the lingering inevitable death of species.

My attention was drawn to this observation by Bernard J., because it relates to the mountains I love and look on every day from my window, (although I am not aware of any Gondwanan Nothofagus within walking distance of our place):
In Australia one good example is the remnant Gondwanan Nothofagus forest associations clinging to the tops of the highest mountain peaks along the Great Dividing Range. Whilst they might be able to persist in warm temperatures, they do not thrive as well as the pyrophilic eucalptus associations at lower altitude. Even slight warming increases the frequency of fire, and the capacity for eucalypts to regenerate more quickly than the Nothofagus will see the latter continue to retreat to the apices in the face of advancing eucalyptus forest, and then blink out when there is no more mountain left. This will remove thousands of species unque to the Nothofagus associations, simply because of the vulnerability of one foundation species.

This post on climate change and extinction, from Kate at ClimateSight, is worth reading and reading again. In it she looks at how past extinction events provide ample warning of the disaster we face. has a post about extinctions, written by Barry Brook.

Some biodiversity blogs are listed on the Pimm Group website.

And for those of us who have recently experienced extreme heat, and wondered if we and other species would survive very high temperatures and humidity if it lasted for more than a few days, the answer is probably not, as discussed here.

An illustration of what happens when one part of the food chain is seriously diminished in numbers, is discussed in this recent article about the current reduction in the number of larger fish in the ocean.

Some scientists are proposing intervention by eliminating specific threatened species for the greater good of many more species. A topic that would be highly controversial in the public arena, one imagines.

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