Tree leaves impacted by drought may, in turn, adversely affect the availability of soil nutrients when they fall to the ground, U.S. researchers say.
Scientists at Purdue University found that red maple leaves accumulate about twice as much tannin when exposed to hot, drought-like conditions and those tannins, which are a leaf's defense against herbivores and pathogens, can interfere with the function of common enzymes in soil, a Purdue release reported Tuesday.
Drought not only makes the leave produce more tannin but changes the chemistry of the tannins, Jeff Dukes, a professor of forestry and natural resources, said.
"This suggests that when these leaves fall, they may slow down soil processes such as decomposition and nutrient cycling," he said. "This could, in turn, affect plant growth and nutrient uptake."
Duke directs a National Science Foundation-funded project, the Boston Area Climate Experiment, where plants on several field plots are exposed to different possible future climate conditions using heaters and other means to control their environment.
"We've basically built a big time machine that moves different plots of land into different possible futures by changing temperatures and precipitation levels," Dukes said.
The increase in leaf tannins observed in his experiment could cause leaves to decompose more slowly and also interfere with critical soil enzymes, leaving fewer nutrients for plants, Dukes said.
Share This Article With Planet Earth
