SYDNEY, Nov. 25 (Xinhua) -- An international team has found that while grazing can have positive effects on ecosystem services, changing climates may turn it to negative in some drylands.
Published in Science on Thursday, the study conducted surveys in 326 drylands around the world, collecting information of plants and soils at sites spanning low to high grazing pressure.
The research found grazing pressure was critical for driving ecosystem services, particularly for carbon storage, organic matter decomposition, soil fertility, and the quality and amount of forage produced.
However, due to climate change, the responses of some ecosystem services varied with local grazing pressure, said senior author of the paper, Prof. David Eldridge from the University of New South Wales (UNSW Sydney).
"For example, stocks of soil carbon declined and soil erosion increased as the climate became warmer, but only under high grazing pressure," said Eldridge.
The researcher said effects of increased grazing are different across the globe. Colder drylands with less seasonal rainfall and greater plant diversity would see more positive effects, but warmer, species-poor drylands may become more vulnerable.
The team also observed that a greater diversity of herbivore types was positively linked to some services such as carbon storage, which is critically important as a climate regulator.
Eldridge added that the response of drylands to ongoing climate change may depend on how we managed them locally as the climate heats up.
"There is no one-size-fits-all when it comes to grazing in drylands. Any effects of grazing, particularly overgrazing, will vary across the globe, making it important to consider local conditions and the type and number of livestock and wild herbivores," he said. ■