Saturday, March 28, 2015

Disturbed ecosystems are more sensitive to climate change and its risks

Science World Report: When it comes to climate change, disturbed ecosystems may be at risk. Scientists have found that an ecosystem's resistance to changing climatic conditions is reduced when it's exposed to natural or human-caused disturbances.

The findings actually come from one of the world's longest running climate change experiments. Two of the studies were actually situated in Danish heathland ecosystems, which were studied over the period of several years. The scientists found that climate change impacts on the vegetation were minimal in undisturbed heathland. But that wasn't the case in heathland that was disturbed.

"After a heather beetle outbreak heather plants re-established in control plots, but not in plots subject to extended summer drought," said Inger Kappel Schmidt, one of the researchers, in a news release. "The combination of disturbance and drought caused a shift from heathland to grassland." Results from the experimental sites in other countries also showed similar results. It appeared that ecosystems that were more disturbed were less likely to recover.

"The long-term impact of climate change on plant communities is more dependent on short periods where plants are relatively vulnerable, like regeneration phases, than on the longer periods between disturbances where established vegetation is relatively robust," said Johannes Ransiin, one of the lead authors of the new article. "The higher sensitivity after disturbance should also be considered by land managers. Reducing disturbance intensity and frequency in ecosystems could help making them less vulnerable to climatic change."...

Gillis d'Hondecoeter (circa 1575/1580–1638) painted this image of "Paradise" after 1615

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