A 16-year long study demonstrates the importance of animal grazing in combating climate change

While maintaining soil cover is crucial for maintaining the health of hills, grazing by animals also plays a crucial role in stabilising the ecosystem’s soil carbon pool. Herbivores are essential to the environment, according to a 16-year research, and the loss of grazing could have a severe impact on the global carbon cycle.

According to a study done by scientists at the Indian Institute of Science’s (IISc) Centre for Ecological Sciences (CES) and Divecha Centre for Climate Change (DCCC), experimentally ending grazing caused soil carbon levels to fluctuate more frequently.

The research began in 2005 when Sumanta Bagchi, Associate Professor at CES began studying the impact of grazing animals on Himalayan ecosystems during his PhD. He, along with his team, established fenced plots (where animals were excluded) as well as plots in which animals like yak and ibex grazed.

The scientists tracked and compared the levels of carbon and nitrogen in each plot year after year while collecting soil samples from various locations over the course of a decade. They discovered that, compared to the grazed plots where it was more constant year after year, soil carbon levels fluctuated 30–40% higher from year to year in the enclosed plots where animals weren’t present.

According to a study that was published in the journal Proceedings of the National Academy of Sciences, protecting large mammalian herbivores in grazing ecosystems must continue to be a top priority to maintain soil carbon levels and implement natural climate solutions. ‘Grazing by mammalian herbivores can be a climate mitigation strategy as it influences the size and stability of a large soil carbon (soil-C) pool,’ the paper reads.

Nitrogen, which may stabilise or destabilise the carbon pool depending on the soil conditions, was discovered by researchers to be a major contributor underpinning the carbon variations. ‘Assuming that the accumulation or removal of carbon is a gradual process, many earlier research concentrated on measuring the quantities of carbon and nitrogen over extended time periods. But their data’s interannual changes reveal a totally different picture,’ GT Naidu, a PhD candidate at DCCC and the study’s first author, remarked.