Polar bears have become an icon of the endangered species caused by climate change; but new research indicates that the creatures of the tropics may also be impacted.
As temperatures continue to rise world-wide, much of the attention has gone to the creatures of the Arctic. While there is no doubt that these animals are in danger, the problem spans far beyond the Northern Hemisphere. It is strange to think that the tropics, of all places, could be influenced by an increase in global temperature , but this rise is in fact having a negative impact specifically on reptiles and amphibians of tropic regions.
A study executed by Michael Dillon from the University of Wyoming, spotlights the metabolic effects of climate change. He and his team chose to focus their inquiries on cold-blooded animals, or ectotherms. An ectotherm’s body temperature varies with the temperature of its surroundings, making it a perfect model of the effects of ecological impact. The team compared temperature to metabolic rates at many sites around the world for the past 30 years. The results were fascinating. Although the arctic is warming at a much faster rate than the rest of the world, the metabolic changes due to the warming were not as high as the tropics or even areas just slightly south of the arctic.
“Large effects of recent climate warming on metabolic rates are predicted for invertibrates, amphibians and reptiles in equatorial West Africa, the Caribbean and Central America, Ecuador, eastern equatorial Brazil, and the Persian Gulf region,” claim Dillon, and his collegues, George Wang and Raymond B. Huey.
The warming of tropic regions is less noticeable because of its high baseline temperature, but the impacts of climate change are modelled through physiology and metabolic rate, and are increasing not linearly, but exponentially! The temperature change in the tropics is reasonably small, but considering that it represents most of the earth’s biodiversity, the organisms will be largely affected by climate change. It has been determined that a change in temperature is more impactful at a high temperature rather than at low.
As the ectotherms metabolisms rise, the probable outcome is an increased need for food (and possibly starvation if food is unavailable); more water lost through evaporation, and reduced energy for reproduction.
In the journal Nature, the scientists say, “We assume that surface air temperatures approximate ectotherm body temperatures; therefore, our metabolic estimates apply to thermoconforming and exposed ectotherms. This is reasonable for small ectotherms living in shaded environments, but less so for large ectotherms that live in thermally heterogeneous environments, where behavioural thermoregulation is possible, or for organisms that spend extensive periods in retreats.”
For sufficient data, Dillon and his team went back to 1961 for global temperatures, but the most significant information is from 1980 to today. There is no way to predict what the future will hold without blindly guessing weather patterns, but if this trend continues there is definite potential to lose many species to extinction.
The journal concludes that “...metabolic increases should alter food web dynamics, leading to elevated rates of herbivory and predation, as well as changes in the spread of insect-borne tropical diseases. Because the tropics are the centre of Earth’s biodiversity and its chief engine of primary productivity, the relatively large effects of temperature change on the metabolism of tropical ectotherms may have profound local and global consequences.”
References:
Dillon, Michael, George Wang, and Raymond B. Huey. "Global metabolic impacts of recent climate warming." Nature (2010): n. pag. Web. 10 Oct 2010.
“Large effects of recent climate warming on metabolic rates are predicted for invertibrates, amphibians and reptiles in equatorial West Africa, the Caribbean and Central America, Ecuador, eastern equatorial Brazil, and the Persian Gulf region,” claim Dillon, and his collegues, George Wang and Raymond B. Huey.
The warming of tropic regions is less noticeable because of its high baseline temperature, but the impacts of climate change are modelled through physiology and metabolic rate, and are increasing not linearly, but exponentially! The temperature change in the tropics is reasonably small, but considering that it represents most of the earth’s biodiversity, the organisms will be largely affected by climate change. It has been determined that a change in temperature is more impactful at a high temperature rather than at low.
As the ectotherms metabolisms rise, the probable outcome is an increased need for food (and possibly starvation if food is unavailable); more water lost through evaporation, and reduced energy for reproduction.
In the journal Nature, the scientists say, “We assume that surface air temperatures approximate ectotherm body temperatures; therefore, our metabolic estimates apply to thermoconforming and exposed ectotherms. This is reasonable for small ectotherms living in shaded environments, but less so for large ectotherms that live in thermally heterogeneous environments, where behavioural thermoregulation is possible, or for organisms that spend extensive periods in retreats.”
For sufficient data, Dillon and his team went back to 1961 for global temperatures, but the most significant information is from 1980 to today. There is no way to predict what the future will hold without blindly guessing weather patterns, but if this trend continues there is definite potential to lose many species to extinction.
The journal concludes that “...metabolic increases should alter food web dynamics, leading to elevated rates of herbivory and predation, as well as changes in the spread of insect-borne tropical diseases. Because the tropics are the centre of Earth’s biodiversity and its chief engine of primary productivity, the relatively large effects of temperature change on the metabolism of tropical ectotherms may have profound local and global consequences.”
References:
Dillon, Michael, George Wang, and Raymond B. Huey. "Global metabolic impacts of recent climate warming." Nature (2010): n. pag. Web. 10 Oct 2010.
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