Effect of grazing on methane uptake from Eurasian steppe of China

Shiming Tang,Xiajie Zhai,Chengjie Wang,Kun Wang,Yujuan Zhang,Andreas Wilkes

doi:10.1186/s12898-018-0168-x

Shiming Tang, Xiajie Zhai + Show 4 more

Open Access

https://doi.org/10.1186/s12898-018-0168-x

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Abstract

BackgroundThe effects of grazing on soil methane (CH4) uptake in steppe ecosystems are important for understanding carbon sequestration and cycling because the role of grassland soil for CH4 uptake can have major impacts at the global level. Here, a meta-analysis of 27 individual studies was carried out to assess the response patterns of soil CH4 uptake to grazing in steppe ecosystems of China. The weighted log response ratio was used to assess the effect size.ResultsWe found that heavy grazing significantly depressed soil CH4 uptake by 36.47%, but light and moderate grazing had no significant effects in grassland ecosystem. The response of grassland soil CH4 uptake to grazing also was found to depend upon grazing intensity, grazing duration and climatic types. The increase in soil temperature and reduced aboveground biomass and soil moisture induced by heavy grazing may be the major regulators of the soil CH4 uptake.ConclusionsThese findings imply that grazing effects on soil CH4 uptake are highly context-specific and that grazing in different grasslands might be managed differently to help mitigate greenhouse gas emissions.

Highlights

The effects of grazing on soil methane (CH4) uptake in steppe ecosystems are important for understanding carbon sequestration and cycling because the role of grassland soil for C H4 uptake can have major impacts at the global level
The data suggest that soil C H4 uptake decrease as the grazing intensity increases, the effect is significant only under heavy grazing (− 36.47%, p < 0.05) (Fig. 1)
The results of our study indicate that overgrazing has significant negative effects on the C H4 uptake of grassland soils in China, which would most likely cause a large decrease in soil CH4 uptake and a decrease in carbon sequestration of grassland in China

Summary

Introduction

The effects of grazing on soil methane (CH4) uptake in steppe ecosystems are important for understanding carbon sequestration and cycling because the role of grassland soil for C H4 uptake can have major impacts at the global level. The concentration of atmospheric CH4 has been increasing because of anthropogenic activities over the last 150 years [3], reaching 1813 ppb in 2011, which is 159% higher than the preindustrial level [4]. These changes can exert strong effects on terrestrial carbon cycles and global warming. There is clear evidence that grazing in grassland ecosystems alters the activity or community composition

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