New study finds grazing animals play key role in long-term soil carbon stability

A new study has found benefits of animals grazing in a particular region It has seen that the experimental removal of grazing by herbivores in grazing ecosystems of Spiti region in the Himalayas leads to an increase the fluctuations in the level of soil carbon possibly leading to unintended negative consequences for the global carbon cycleThe study spread over 16 years was carried out by researchers at the Centre for Ecological Sciences CES and the Divecha Centre for Climate Change DCCC Indian Institute of Science IIScLarge mammalian herbivores like the yak and ibex play a crucial role in stabilising the pool of soil carbon in grazing ecosystems such as the Spiti region in the Himalayas according to the studySince soil contains more carbon than all plants and the atmosphere combined it is important to ensure its persistence When plants and animals die dead organic matter remains in the soil for a long duration before microbes break it down and release carbon into the atmosphere as carbon dioxide aceThe soil pool is a reliable sink for trapping carbon explains Sumanta Bagchi associate professor at CES and senior author of the study published in the Proceedings of the National Academy of SciencesMaintaining stable levels of carbon in the soil is therefore key to offsetting the effects of climate change the IISc release statesBagchi began studying the impact of grazing animals on Himalayan ecosystems during his PhD back in 2005 With support from the Himachal Pradesh state government local authorities and the people of the Kibber village in Spiti he and his team established fenced plots where animals were excluded as well as plots in which animals like yak and ibex grazed Over the following decade he and his students collected soil samples from the region and analysed their chemical composition tracking and comparing the levels of carbon and nitrogen in each plot year after yearFrom one year to the next soil carbon was found to fluctuate 3040 per cent more in the fenced plots where animals were absent compared to the grazed plots where it remained more stable each year A key factor underlying these fluctuations was nitrogen Depending on the soil conditions nitrogen can either stabilise or destabilise the carbon pool Grazing by herbivores however changes their interactions in ways that tip the balance in favour of the former the researchers foundMany previous studies have focused on measuring carbon and nitrogen levels at long time intervals assuming that the accumulation or loss of carbon is a slow process explains Dilip GT Naidu PhD student at DCCC and first author of the study But the interannual fluctuations they noticed in their data paint a very different picture he adds These fluctuations can be consequential for climate as they are linked to how large mammalian herbivores influence soil the IISc release statedBecause grazing ecosystems make up about 40 per cent of the Earths land surface protecting the herbivores that keep the soil carbon stable should remain a key priority for mitigating climate change the researchers suggestBoth domestic and wild herbivores influence climate via their effects on soil carbon explains Shamik Roy a former PhD student at CES and another author of the study In ongoing research Bagchi and his team are also assessing why domestic herbivores such as goat and sheep differ from their wild relatives in how they impact ecosystems Domestic and wild herbivores are very similar in many respects but they differ in how they influence plants and soil Understanding why they are not alike can lead us toward more effective stewardship of soil carbon Roy addsAlso Read 60 million years of climate change triggered rise of reptiles StudyThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever