不同放牧强度对典型草原区河谷湿地土壤碳氮磷生态化学计量特征的影响  

Effects of Different Grazing Intensities on Ecological Stoichiometric Characteristics of Soil Carbon,Nitrogen and Phosphorus in Typical Grassland Valley Wetlands

作　　者：褚少杰 王怡璇 段利民[1,2] 孙金 张桂馨 刘廷玺 CHU Shaojie;WANG Yixuan;DUAN Limin;SUN Jin;ZHANG Guixin;LIU Tingxi(The College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;Inner Mongolia Water Resource Protection and Utilization Key Laboratory,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018 [2]内蒙古自治区水资源保护与重点实验室,内蒙古呼和浩特010018

出　　处：《中国草地学报》2023年第10期12-21,共10页Chinese Journal of Grassland

基　　金：国家自然科学基金(51939006);内蒙古自治区科技计划项目(2021GG0072);内蒙古自治区水资源保护与利用重点实验室建设项目(2020PT0001);内蒙古自治区高校青年科技英才项目(NJYT22037);内蒙古农业大学青年教师科研能力提升专项(BR220104);内蒙古自治区研究生科研创新项目(S202110226Z)。

摘　　要：为了探究半干旱草原区河谷湿地土壤碳氮磷生态化学计量特征对放牧干扰的响应,明确限制其土壤养分循环的关键因子,以内蒙古典型草原区的锡林河河谷湿地为研究对象,在轻度、中度、重度3种放牧情境下开展野外观测试验,测定0~50 cm土层的土壤基本理化性质、碳氮磷含量及其生态化学计量特征。结果表明:(1)湿地0~40 cm土壤的理化性质对放牧干扰响应较为敏感,适当放牧可以促进土壤养分积累,但重度放牧导致土壤碳氮磷含量及其生态化学计量比显著降低。(2)放牧活动通过影响植被生长及土壤理化性质对养分循环产生影响,在轻度和中度放牧条件下土壤磷元素可能是限制湿地土壤养分元素循环的关键因子,而在重度放牧条件下磷元素的限制作用减小,氮元素的限制作用增加。(3)过度放牧可能会破坏土壤原有的养分循环和物质平衡,随放牧强度的增加,湿地土壤生态化学计量特征与土壤理化性质间的相互作用总体呈减弱趋势,而土壤容重可能是影响其生态化学计量特征的关键环境因子。This study aimed to investigate the impact of grazing disturbance on the ecological stoichiometry characteristics of soil carbon,nitrogen,and phosphorus in a semi-arid grassland valley wetland.The research also aimed to elucidate the primary factors influencing soil nutrient cycle.Field observation experiments involving three grazing intensities(mild,moderate,and severe)were conducted.The study focused on assessing the fundamental physical and chemical properties,as well as the carbon(C),nitrogen(N)and phosphorus(P)contents,and ecological stoichiometry characteristics of the 0~50 cm soil layer in the Xilin River Valley wetland,located within the typical grassland area of Inner Mongolia.The results showed the following key findings:1)Grazing disturbance significantly influenced the physical and chemical properties of the 0~40 cm soil in the wetland.Appropriate grazing practices were found to enhance soil nutrient accumulation,whereas heavy grazing resulted in a substancial decline in soil carbon,nitrogen,and phosphorus contents,as well as their ecological stoichiometric ratios.2)Grazing activities exerted an impact on nutrient cycling through their effects on vegetation growth and soil physicochemical properties.In case of mild and moderate grazing,soil P appeared to be the primary limiting factor for nutrient cycling in wetland soil,although its influence diminished under heavy grazing conditions,with N limitations becoming more prominent.3)Overgrazing had the potential to disrupt the original nutrient cycle and soil equilibrium.As grazing intensity increased,the interaction between ecological stoichiometric characteristics of wetland soil and its physicochemical properties generally weakened.Notably,soil bulk density emerged as a key environmental factor affecting these ecological stoichiometric characteristics.

关 键 词：草原区河谷湿地 生态化学计量学 放牧强度 土壤理化性质 

分 类 号：S812.2[农业科学—草业科学]