Mediterranean, semi-arid ecosystems prove resistant to climate change

Mediterranean, semi-arid ecosystems prove resistant to climate change

Climate change predictions for the Middle East, like other arid regions of the world, are alarming. In an area known for its water scarcity, rainfall is expected to decrease even further in the near future, spelling disaster for the functioning of unique ecosystems—hotspots of biodiversity and rich genetic fodder for essential crops.

To test these dire predictions, Prof. Marcelo Sternberg of the Department of Molecular Biology and Ecology of Plants at Tel Aviv University's Faculty of Life Sciences, together with ecologists from the University of Tübingen in Germany, subjected natural ecosystems to an experimental drought over the course of nine years, simulating predicted future climate scenarios.

In the course of their experiment, conducted in four different ecosystems ranging from desert (3.5 inches of annual rainfall) to moist Mediterranean woodland (30.7 inches of annual rainfall), the researchers found that, contrary to predictions, no measurable changes in annual vegetation could be seen. None of the crucial vegetation characteristics—neither species richness and composition, nor density and biomass (particularly important for ecosystems traditionally used as rangelands)—had changed appreciably in the course of the rainfall manipulations.

"Based on our study, the going hypothesis that all semiarid regions will react strongly to climate change needs to be revised," states Prof. Sternberg. The surprising results of the study were recently published in Nature Communications.

A natural comfort zone

The affected ecosystems proved resilient, likely due to the highly variable amounts of for which the regions are known. The experimental climate changes, which simulated a decrease of about 30 percent of current rainfall, seem to fall within the natural "comfort zone" of wild plants.

In their experiment, the scientists were intent on testing one of the basic assumptions of climate change—that an affected plant species will migrate to more hospitable areas in order to survive. The researchers tested for two possible alternatives: first, a species dying off due to its inability to migrate to new and more suitable areas, and second, other varieties of the same species adapting to the new conditions created by the climate change.

"This second option has been overlooked by most researchers," said Prof. Sternberg, who found local adaptation to be the primary course of action for the plant communities that were tested.

Broad and extensive study

"Our experiment is likely the most extensive climate change study ever done, because of the number of sites involved, the long duration of experimental manipulations, and the immense species richness," said Prof. Sternberg.

According to Prof. Sternberg, the Mediterranean and semi-arid annual plant communities would be little affected by , at least in the short to medium term. However, it cannot be ruled out that species composition could change after 20-30 years, because natural short-term climatic variations impose a different selection regime on organisms than a long-term trend of changing climate conditions.

Prof. Sternberg is currently searching for a new collaboration and funding to maintain the long-term experiment and expand its breadth and scope.

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Journal information: Nature Communications

Citation: Mediterranean, semi-arid ecosystems prove resistant to climate change (2014, October 20) retrieved 17 October 2019 from
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Oct 20, 2014
Excellent news. But good luck with that: "Prof. Sternberg is currently searching for a new collaboration and funding to maintain the long-term experiment and expand its breadth and scope."

Oct 20, 2014
Another nail in the AGW Cult's coffin of CO2 lies.
Only in the AGW Cult's dogma, is there doom and gloom.

The "science" is settled??????

Oct 20, 2014
Why do we still have Deniers? I think they do it for the attention.

Oct 20, 2014
Why do we still have AGW religionists? I Know..... progressives don't think for themselves, then there are the Paid Progressive Government Trolls, then there are government folks who want even bigger government, then there are researchers who couldn't get funding unless they claim somehow their research is related to AGW, then there are the fortune makers like Al Gore who make a killing out of using dumb AGW Progressive fools,

Oct 20, 2014
And then, there are the liberals and the monsters under his bed!

Oct 21, 2014
Why do we still have Deniers? I think they do it for the attention.

Ah, the very definition of stupid, opens it's mouth to confirm it.
Hey gkam, eat switchgrass much?

Oct 25, 2014
it is unfortunate that israel, of all place with so many brains, is falling under the corruption of financialization which is ruining the capacity of the country to fix its environmental problem, it's ONE and ONLY environmental problem ; WATER.

there is one obvious solution. 'emek yisrael' a valley in the north going from the bay of haifa across 30 miles to the jordan river used to be under water millions of years ago, completing an open channel from the meditteranean to the red sea.

opening this channel once again , crreating a major water way and a small inland sea lane would not only dramatically increase the productivity of the israel and transjordan areas , both in terms of geographical benefits ( more coastline) and biological benefits ( helping reverse dessertification ) but it would inevitably help improve the delivery of moisture to the farms in israel's southern desserts.

jordan would benefit similarly. and yet similar plans are stalled due to entrenched interes

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