文献类型： 外文期刊

作者： Rong, Yuping ¹ ; Monaco, Thomas A. ² ; Liu, Zhongkuan ³ ; Zhao, Mengli ⁴ ; Han, Guodang ⁴ ;

作者机构： 1.China Agr Univ, Coll Grassland Sci & Technol, Beijing 100193, Peoples R China

2.Utah State Univ, ARS, USDA, Forage & Range Res Lab, Logan, UT 84322 USA

3.Hebei Acad Agr & Forestry Sci, Inst Agroresource & Environm, Shijiazhuang, Hebei, Peoples R China

4.Inner Mongolia Agr Univ, Minist Educ, Key Lab Grassland Resources, Hohhot 010021, Peoples R China

关键词： Grazing intensity; Plant species richness; Microbial biomass; Microbial communities

期刊名称：EUROPEAN JOURNAL OF SOIL BIOLOGY （ 影响因子：3.232； 五年影响因子：4.009 ）

ISSN： 1164-5563

年卷期： 2022 年 110 卷

页码：

收录情况： SCI

摘要： Grazing intensity influences the productivity and sustainability of grassland systems through modifying aboveground biomass, soil microbes, and nutrient dynamics. Although heavy grazing is a key factor associated with grassland degradation in China and alleviating grazing intensity can assist grassland vegetation restoration, the influence of variable grazing intensity on belowground processes is less understood. We examined the effects of four grazing intensities (0, 1.00, 1.43 and 2.33 sheep-units ha- 1 year -1) applied during five growing seasons on soil microbial biomass and community structure of a grassland ecosystem in Hebei Province, China. Within each grazing intensity, vegetation and soil were sampled in three patch types: low and high plant species richness and one composed of the dominant species (i.e., Leymus chinensis [Trin.], Tzvel. and Carex duriuscula C. A. Mey.). We sought to clarify whether soil microbial communities are influenced by an interaction between grazing intensity and patch type. Grazing significantly (P < 0.05) decreased soil microbial biomass and increased the ratio of bacterial-to-fungal biomass relative to the non-grazed control, but differences were not significant among the grazing intensities. Patch type did not significantly impact microbial biomass (P = 0.12), but the interaction between patch type and grazing intensity was significant (P < 0.05). The highest microbial biomass value (19.20 +/- 0.51 mu g.g(-1)) was found in non-grazed, low diversity patches. In addition, principal components analysis revealed that grazing intensity explained 25.42 and 54.53% of the variation among bacterial and fungi communities, respectively. Grazing, regardless of intensity, also resulted in bacterial communities distinct from the non-grazed control. Redundancy analysis also revealed that soil pH and organic carbon had the strongest influence on bacterial community structure, soil electrical conductivity and NO3--N primarily influenced fungi community structure. Collectively our results indicate that microbial communities in semiarid grasslands can remain structurally stable even when subjected to persistent environmental change imposed by grazing pressure.