Tibetan sheep grazing modifies rodent density and their interactions effect on GHG emissions of alpine meadow

Yingxin Wang,Guang Li,Yi Sun,Hang Yuan,Fujiang Hou,Xinglu Zhang,Shenghua Chang

doi:10.1038/s41598-019-53480-z

Yingxin Wang, Guang Li + Show 5 more

Open Access

https://doi.org/10.1038/s41598-019-53480-z

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Abstract

Digging and mound-building by rodents lead to considerable disturbances in the topsoil and may affect plant composition, soil properties. However, little is known about the effects of these activities on GHG emissions, especially under different grazing management. This paper aimed to measure changes in CO2 and CH4 efflux with varying grazing management during the warm and cold seasons and to relate CO2 and CH4 efflux to pika burrow density and zokor mound density with different grazing management. Results of this study showed that CO2 efflux was significantly affected by the grazing season, whereas CH4 efflux was significantly affected by the grazing system. There were significant relationships between GHG efflux and rodent population density which were regulated by grazing management. CO2 efflux increased linearly with rodent density under seasonal continuous grazing in warm season. CO2 and CH4 efflux and rodent population density showed a significant quadratic convex relationship under rotational grazing at 24 SM/ha in warm and cold seasons and rotational grazing at 48 SM/ha in cold season. Under rotational grazing at light stocking rate (24 SM/ha), appropriate populations of rodents were beneficial for decreasing GHG emissions. This results also used to help drive a best-practices model for grazing practices of local herders.

Highlights

Rodents tend to live in large populations and are widely distributed throughout the world; they play a major role in the structure and function of many ecosystems[1,2]
The hypotheses were i) GHG emissions and rodent density were both effected by grazing management; ii) relationship between GHG emissions and rodent density were complex and these relationships were regulated by grazing management
The RDA analysis in this study indicated that aboveground biomass and soil moisture are good explanations for variations in GHG emissions

Summary

Introduction

Rodents tend to live in large populations and are widely distributed throughout the world; they play a major role in the structure and function of many ecosystems[1,2]. The chamber method was used to measure CO2 and CH4 efflux in alpine meadow of the QTP with different plateau pika and zokor densities (as determined by burrow and mound numbers) and under different grazing practices during both the warm and cold seasons in 2010 and 2011. To our knowledge, this is the first pastoral study on the QTP to attempt a complete and controlled assessment of GHG emissions taking into account populations of both livestock and native rodents. The hypotheses were i) GHG emissions and rodent density were both effected by grazing management; ii) relationship between GHG emissions and rodent density were complex and these relationships were regulated by grazing management

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