Global warming to impact species in the tropics more acutely.

PHOTO OF THE DAY: Filtered sunlight gives of a blue aura inside an ice fumarole (an ice tube formed around a volcanic steam vent) atop Mount Erebus, the Earth’s southernmost active volcano.

Ice fumerole Mount Erebus

Photograph by: Aaron Spitzer, National Science Foundation. Date Taken: December 9, 1999.

An interesting study was released recently that has implications for species in tropical areas. Scientists from UCLA and the University of Washington reported on May 6 in Proceedings of the National Academy of Sciences that global warming will have more impact on tropical species than those at higher latitudes. “At least for the short term, the impact of global warming will have opposing effects. In the tropics, warming will reduce insects’ ability to reproduce; in the high latitudes, the ability of organisms to reproduce will increase slightly,” said Curtis Deutsch, UCLA Assistant Professor of Atmospheric and Oceanic Sciences and co-author of the study. If warming continues, the insects in the high latitudes would eventually be adversely affected as well.

In addition to losses in areas of concentration of biodiversity there are further important effects highlighted by Professor Deutsch:

“what hurts the insects hurts the ecosystem. Insects carry out essential functions for humans and ecosystems — such as pollinating our crops and breaking down organic matter back into its nutrients so other organisms can use them. Insects are essential to the ecosystem.”

He also posits that in the tropics, warming will reduce insects’ ability to reproduce but they may adapt by migrating toward higher elevations. It seems this will not be restricted to insects but will include other species like turtles, lizards, frogs and toads. They will do much worse in the tropics than in the high latitudes.

In fact, Professor Deutsch argues that small temperature changes in the tropics will be felt more acutely than at the poles. “A 1-degree temperature change in Panama will not be felt the same way by an organism as a 1-degree temperature change in Alaska.” It will have a greater impact in Panama. He explains it in this way:

“The range of temperature tolerance that an organism has is largely dependent on how much temperature variability it experiences. In the tropics, the amount of temperature variability is very small; there is little difference between summer and winter, while in Alaska, the seasons are dramatically different.

To live in their environments, organisms in the tropics should have a relatively narrow tolerance for temperature change, while in the high latitudes, organisms should be able to tolerate a much wider variation in temperature.”

Reports recently show that warming is already affecting forests in Canada and Europe by enabling insects that threaten trees to survive winter periods. And in yet another scientists found that birds can adjust their behaviour in the face of climate change. A population of birds in Wytham Woods, near Oxford, are now laying their eggs, two weeks earlier than half a century ago. This lets them to feed on caterpillars that now also occur around two weeks earlier due to warmer spring temperatures.

All this points to major changes for the ecology of the Earth with some species disappearing while others may adapt and move into new areas. Insect life has a history of adaptability to change but populations other species like amphibians, reptiles and the forests of the planet may change drastically or disappear altogether.

~ by abstraktbiblos on Tuesday, 13 May, 2008.

One Response to “Global warming to impact species in the tropics more acutely.”

  1. […] State University Global warming to impact species in the tropics more acutely. » This Summary is from an article posted at Green Icebergs – a look at the world from a different […]

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