Predators have outsized influence over habitats | Science Codex

Predators have outsized influence over habitats | Science Codex
http://www.sciencecodex.com/predators_have_outsized_influence_over_habitats-93424

A grasshopper's change in diet to high-energy carbohydrates while
being hunted by spiders may affect the way soil releases carbon
dioxide into the atmosphere, according to research results published
this week in the journal Science.

Grasshoppers like to munch on nitrogen-rich grass because it
stimulates their growth and reproduction.

But when spiders enter the picture, grasshoppers cope with the stress
from fear of predation by shifting to carbohydrate-rich plants,
setting in motion dynamic changes to the ecosystem they inhabit,
scientists have found.

"Under stressful conditions they go to different parts of the 'grocery
store' and choose different foods, changing the makeup of the plant
community," said Oswald Schmitz, a co-author of the paper and an
ecologist at Yale University.

The high-energy, carbohydrate diet also tilts a grasshopper's body
chemistry toward carbon at the expense of nitrogen.

So when a grasshopper dies, its carcass breaks down more slowly, thus
depriving the soil of high-quality fertilizer and slowing the
decomposition of uneaten plants.

Grasshoppers' diets while being hunted may affect how soil releases
carbon dioxide.