Climate crisis is changing grasslands across world: study

PTI, Sep 7, 2019, 4:07 PM IST

Washington: Grasslands across the world are transforming due to the climate crisis factors such as rising carbon dioxide levels, hotter temperatures, extra nutrient pollution, or drought, a study says.

Looking at 105 grassland experiments across the world, the plant species in these places began to shift after 10 years of exposure to one of the factors linked to climate change, according to a study by researchers at the Michigan State University in the US.

The scientists found that the identity of grasslands can change drastically, without altering the number of species. In nearly half the plots examined, individual plant species had changed, with the total number of species remaining the same.

However, in some plots, there was a transformation of the grasslands with entirely new species, the study, published in the journal Proceedings of the National Academy of Sciences, noted.

Each of the 105 experiments tested at least one climate crisis factor, and some looked at two or more of the factors.

Meghan Avolio, co-author and assistant professor of ecology at Johns Hopkins University said that grasslands are highly resilient but added that when altering conditions arrive, the change can be very important.

Half of the experiments lasting 10 years or more found a change in the total number of plant species, and nearly three-fourths found changes in the types of species, according to the study.

By contrast, the study noted, only 20 per cent of the experiments that lasted less than 10 years picked up any species changes at all.

The researchers note that grasslands are critical allies in the fight against climate change as they make up more than 40 per cent of the world’s ice-free land, and also hold up to 30 per cent of the world’s carbon.

The study provides evidence that human activities may have widespread global impacts on plant community composition, becoming increasingly prevalent with time, and more severe in areas where communities face multiple climate crisis factors simultaneously.