Different grassland managements significantly change carbon fluxes in an alpine meadow

Ganjun Xu; Xiaoming Kang; Wei Li; Yong Li; Yongyu Chai; Shengyi Wu; Xiaodong Zhang; Zhongqing Yan; Enze Kang; Ao Yang; Yuechuan Niu; Xiaodong Wang; Liang Yan

doi:10.3389/fpls.2022.1000558

Different grassland managements significantly change carbon fluxes in an alpine meadow

Front Plant Sci. 2022 Oct 13:13:1000558. doi: 10.3389/fpls.2022.1000558. eCollection 2022.

Authors

Ganjun Xu¹, Xiaoming Kang^{2

3

4}, Wei Li^{2

3

4}, Yong Li^{2

3

4}, Yongyu Chai¹, Shengyi Wu¹, Xiaodong Zhang^{2

3

4}, Zhongqing Yan^{2

3

4}, Enze Kang^{5

6}, Ao Yang^{2

3

4}, Yuechuan Niu⁷, Xiaodong Wang^{2

3

4}, Liang Yan^{2

3

4}

Affiliations

¹ Institute of Northwest Surveying and Planning, National Forestry and Grassland Administration, Xi'an, China.
² Wetland Research Center, Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing, China.
³ Sichuan Zoige Wetland Ecosystem Research Station, Tibetan Autonomous Prefecture of Aba, Sichuan, China.
⁴ Beijing Key Laboratory of Wetland Services and Restoration, Chinese Academy of Forestry, Beijing, China.
⁵ Institute of Botany, Chinese Academy of Sciences, Beijing, China.
⁶ University of Chinese Academy of Sciences, Beijing, China.
⁷ College of Life Sciences, University of the Chinese Academy of Sciences, Beijing, China.

Abstract

Alpine meadow plays vital roles in regional animal husbandry and the ecological environment. However, different grassland managements affect the structure and function of the alpine meadow. In this study, we selected three typical grassland managements including free grazing, enclosure, and artificial grass planting and conducted a field survey to study the effects of grassland managements on carbon fluxes in an alpine meadow. The carbon fluxes were observed by static chamber and environmental factors including vegetation and soil characteristics were measured simultaneously. Our results show that the alpine meadow was a CO₂ and CH₄ sink, and grassland managements had a significant effect on all CO₂ fluxes, including gross ecosystem production (GEP, P< 0.001), net ecosystem production (NEP, P< 0.001) and ecosystem respiration (ER, P< 0.001) but had no significant effect on CH₄ fluxes (P > 0.05). The ranking of GEP under the different grassland managements was enclosure > free grazing > artificial grass planting. Furthermore, NEP and ER at enclosure plots were significantly higher than those of the free grazing and artificial grass planting plots. In addition, different grassland managements also affected the vegetation and soil characteristics of the alpine meadow. The aboveground biomass of artificial grass planting was significantly higher than that of the free grazing and enclosure plots. The vegetation coverage under three different grassland managements was ranked in the order of enclosure > artificial grass planting > free grazing and significant differences were observed among them. Moreover, significant differences in the number of species (P< 0.01) and the Margalef richness index (P< 0.05) were detected under three different grassland managements. Further analysis of the relationship between environmental factors and carbon fluxes revealed that GEP and NEP of the alpine meadow were positively correlated with vegetation coverage, the number of species, and the Margalef richness index. Therefore, grassland restoration should be configured with multiple species, which could improve carbon sink capacity while considering the functions of grassland restoration and production.

Keywords: alpine meadow; artificial grass planting; carbon fluxes; enclosure; grazing.