By Richard Romano on June 22nd, 2012
Here’s an interesting study that shows how something seemingly small, inconsequential and, on the surface of it, silly to say, can lead to major changes in an ecosystem. That seemingly small, silly something? Grasshoppers that are afraid of spiders.
Yes, I chuckled a bit (but then I am not particularly afraid of spiders, but I do know people who may be siding with the grasshoppers here), but bear with me…
As anyone who has lived in a state of fear or stress can tell you, that heightened state can affect what we eat. So just as we may down a whole pint of Ben & Jerry’s, so, too, will a frightened grasshopper consume more carbs—in its case, plants. (It doesn’t have to be a spider; any potential attacker will do, maybe even Peter Graves.) And then the process begins:
When the scared grasshopper dies, its carcass, now containing less nitrogen as a result of its diet change, will have an effect on the microbes in the ground, which are responsible for breaking down animals and plants.
With less nitrogen available, the microbes will be decomposing the hard-to-break-down plant materials in the soil at a slower rate. Thus, the fear of predation may slow down degradation of complex organic materials to the simpler compounds required for plant growth.
The researchers, from the Hebrew University of Jerusalem, taking up with colleagues at Yale University, compared a test group of grasshoppers they “scared” against a control group of non-scared grasshoppers, and found that the former group had higher carbon-to-nitrogen levels in their bodies than the latter group.
“We are dealing here with an absolutely new kind of mechanism whereby every small chemical change in a creature can regulate the natural cycle, thus in effect affecting the ecology in total, such as the amount of carbon dioxide released into the atmosphere (through decomposition) and field crop productivity. This has tremendous consequences for our ecological understanding of the living world,” said [Dr. Dror Halwena of the Department of Ecology, Evolution and Behavior at the Alexander Silberman Institute of Life Sciences at the Hebrew University of Jerusalem].
The study appears in the latest issue of Science.