青藏高原高寒草甸微地形对土壤胞外酶活性及生态化学计量比的影响  

Effects of microtopography on enzyme activities and ecological stoichiometry in an alpine meadow on the Qinghai-Tibet Plateau

作　　者：李欣蔚 肖元明 李春丽 高永恒[5] 周国英[3,4] LI Xinwei;XIAO Yuanming;LI Chunli;GAO Yongheng;ZHOU Guoying(College of Ecol-Environmental Engineering,Qinghai University,Xining 810016,China;State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China;Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810008,China;Key Laboratory of Tibetan Medicine Research,Chinese Academy of Sciences,Xining 810008,China;Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610213,China)

机构地区：[1]青海大学生态环境工程学院,西宁810016 [2]青海大学省部共建三江源生态与高原农牧业国家重点实验室,西宁810016 [3]中国科学院西北高原生物研究所,西宁810008 [4]中国科学院藏药研究重点实验室,西宁810008 [5]中国科学院成都生物研究所,成都610213

出　　处：《应用与环境生物学报》2024年第2期212-219,共8页Chinese Journal of Applied and Environmental Biology

基　　金：中国科学院战略性先导科技专项(XDA26020201-2);青海省自然科学基金团队项目(2023ZJ902T);青海大学生态环境工程学院研究生三江源生态一流学科科技创新项目(2022stxy Y7)资助。

摘　　要：高寒草甸的生态化学计量特征是当前生态学研究的热点问题之一.以青藏高原高寒草甸为研究对象,测定3种微地形(阴坡、阳坡和沟底)的土壤养分含量以及与碳、氮、磷循环相关的酶活性;同时,调查植物群落特征、土壤pH和含水量(SWC),计算植物物种多样性指数、土壤关键元素及相应胞外酶的生态化学计量比,探究小尺度高寒草甸上微地形对土壤关键元素、胞外酶活性及相应生态化学计量比的影响因素.结果表明:(1)不同微地形条件下,植物群落组成和多样性差异极显著,阳坡植物多样性最高,阴坡最低(P<0.001).(2)在测定的所有指标中,土壤pH和酸性磷酸酶(AP)在阴坡最高,阳坡的土壤总磷(TP)含量最高,其余指标无显著变化.(3)微地形造成的植物多样性的改变是影响土壤C:N的重要原因,物种多样性与土壤C:N存在极显著的负相关性(P<0.01).(4)地下生物量与土壤C:N具有显著的正相关关系(P<0.05),说明生物量差异是主导土壤C:N变化的关键因素之一.(5)植被因素、土壤pH和土壤TP含量共同调控土壤关键元素和相应胞外酶的生态化学计量在微地形中的变化.本研究表明微地形导致的植物群落特征和土壤理化性质的差异对胞外酶活性及生态化学计量比变化具有重要影响,结果可为厘清未来气候变化背景下青藏高原高寒草甸关键元素循环过程提供重要的理论支持.(图4表5参50)The ecological stoichiometric characteristics of soil and enzymes are important in alpine meadows.This study focused on the critical parameters of soil,extracellular enzymes,and vegetation to explore the effects of microtopography shady slope,sunny slope,and ravine)on soil and extracellular enzyme stoichiometry,along with the influencing factors in a small-scale alpine meadow on the Qinghai-Tibet Plateau.We determined the levels and activities ofβ-1,4-glucosidase(BG),cellulose disaccharide hydrolase(CBH),β-1,4-acetyl-glucosaminidase(NAG),leucine aminopeptidase(LAP)and acid,phosphatase(AP)in the soil.Next,the ecological stoichiometric ratios of the soil and extracellular enzymes were calculated.Additionally,we investigated plant community characteristics and below-ground biomass to calculate the vegetation species diversity index,as well as measured soil pH and water content(SWC).The results showed that:(1)Microtopography had significant effects on soil total phosphorus,acid phosphatase,and pH(P<0.05),but did not affect the other soil indicators(P>0.05).(2)Microtopography had a significant effect on plant community composition and diversity,with the highest plant diversity on sunny slopes and the lowest on shady slopes(P<0.001).(3)Variations in vegetation diversity caused by microtopography were essential factors affecting soil C:N,and plant species presented a significantly negative effect on soil C:N(P<0.01).(4)A significant positive correlation was found between root biomass and soil C:N ratio,indicating that vegetation productivity is a key factor leading to soil C:N change.(5)Vegetation factors and soil pH and soil total phosphorus content jointly regulate soil enzyme activities and the ecological stoichiometry of soil enzymes in the microtopography.Generally,the variations in plant community characteristics and soil properties caused by microtopography significantly affected soil enzyme activities and soil-enzyme ecological stoichiometry in alpine meadows.The results of this study provide the necessary the

关 键 词：土壤酶活 生态化学计量 微地形 高寒草甸 物种多样性 

分 类 号：G63[文化科学—教育学]