放牧干扰下天山北坡中段植物功能群特征及其与土壤环境因子的关系  

Characteristics of plant functional groups and the relationships with soil environmental factors in middle part of northern slope of Tianshan Mountains under different grazing intensities

作　　者：江康威 张青青 王亚菲 李宏[1] 丁雨 杨永强 吐尔逊娜依·热依木[2] JIANG Kang-Wei;ZHANG Qing-Qing;WANG Ya-Fei;LI Hong;DING Yu;YANG Yong-Qiang;Tuerxunnayi REYIMU(Grass Industry College,Xinjiang Agricultural University,Urumqi,830052,China;College of Life Sciences,Xinjiang Agricultural University,Urumqi,830052,China;College of Resource and Environment,Xinjiang Agricultural University,Urumqi,830052,China)

机构地区：[1]新疆农业大学草业学院,乌鲁木齐830052 [2]新疆农业大学生命科学学院,乌鲁木齐830052 [3]新疆农业大学资源与环境学院,乌鲁木齐830052

出　　处：《植物生态学报》2024年第6期701-718,共18页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(2522GZRJJ和41561103)。

摘　　要：放牧是导致草地生态系统发生变化的重要驱动因素,然而在不同放牧强度下草地植物群落与功能群对土壤因子的响应是否一致目前仍不明确。该研究以天山北坡中段草地为研究对象,基于野外植物群落调查和室内土壤分析,分析放牧对植物群落与功能群的影响,以此为基础进一步揭示在放牧干扰下植物群落和功能群对土壤因子响应的差异。结果表明,轻度放牧和未放牧草地的主要优势功能群为多年生禾草和莎草,重度放牧样地中的主要优势功能群为毒害草,优势种为醉马草(Achnatherum inebrians)。相较于重度放牧,轻度放牧显著提高多年生禾草、豆科植物、莎草和杂类草功能群的地上生物量,显著降低了毒害草地上生物量。轻度放牧的物种多样性指数显著高于重度放牧;而在功能群多样性中,轻度放牧的Shannon-Wiener指数、Margalef指数和Pielou指数显著高于重度放牧,Simpson指数在不同放牧强度间无显著差异。冗余分析、Mantel检验以及结构方程模型的结果显示,植物群落特征、功能群和群落多样性与土壤有机碳含量、速效氮含量、速效钾含量、全磷含量、全钾含量、土壤密度和土壤含水量均存在显著相关关系;放牧直接对草地植物高度、盖度、密度、地上生物量、植物群落和功能群多样性产生显著的负向影响,也可通过提高土壤密度和降低土壤养分含量从而对群落高度、盖度、密度、地上生物量、植物群落和功能群多样性产生间接的负向影响。综上,在放牧干扰下,土壤因子对维持天山北坡中段草地植物群落的稳定生长起到至关重要的作用,该结果为新疆草地植物资源的合理利用提供科学依据。Aims Despite grazing being a significant driving factor for grassland ecosystems,it remains uncertain whether the responses of grassland plant communities and functional groups to soil variables remain consistent across grazing intensity gradients.Methods This study conducted field plant community surveys in the middle part of the northern slope of Tianshan Mountains,and lab soil analysis.It aimed to analyze the impact of grazing on plant communities and functional groups,as well as reveal differences in their responses to soil factors under grazing intensity.Important findings The results indicated that perennial grasses and sedges were the main dominant functional groups in light grazing and no grazing sites.However,heavy grazing sites had poisonous grasses as dominant functional groups,with Achnatherum inebrians being the dominant species.Light grazing significantly increased above-ground biomass for functional groups such as perennial grasses,legumes,sedges,and forbs while notably decreased for poison grasses compared to heavy grazing along the gradient.In terms of functional group diversity,Shannon-Wiener index,Margalef index,and Pielou index were significantly higher under light grazing than heavy grazing;however,Simpson index did not show significant differences between different levels of grazing intensity.Results from redundancy analysis,Mantel test,and structural equation models demonstrated significant correlations between plant community characteristics(including functional groups),community diversity indices(Shannon-Wiener index),and various soil factors such as organic carbon content,available nitrogen content,available potassium content,total phosphorus content,total potassium content,soil density,soil water content.Grazing directly exerted a significant negative impact on grassland height,coverage,density,aboveground biomass,diversity within both plant communities and functional groups.The soil density increase and soil nutrient reduction caused by grazing can also impact community height,coverage

关 键 词：放牧 植物功能群 土壤因子 Mantel检验 结构方程模型 天山北坡 

分 类 号：Q948[生物学—植物学]