放牧强度对高寒草地土壤微生物胞外酶化学计量的影响  

Effect of Grazing Intensities on Extracellular Enzyme Stoichiometry of Soil Microorganisms in Alpine Grassland

作　　者：潘森 卜嘉玮 甘安琪 尚振艳[1] 郭丁[1] 杨晓霞 董全民[2] 牛得草[1] PAN Sen;BU Jia-wei;GAN An-qi;SHANG Zhen-yan;GUO Ding;YANG Xiao-xia;DONG Quan-min;NIU De-cao(State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems,Key Laboratory of Grassland Livestock Industry Innovation,Ministry of Agriculture and Rural Affairs,Engineering Research Center of Grassland Industry,Ministry of Education,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou,Gansu Province 730020,China;Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland,Qinghai Academy of Animal Science and Veterinary Medicine,Qinghai University,Xining,Qinghai Province 810016,China)

机构地区：[1]兰州大学草种创新与草地农业生态系统全国重点实验室,兰州大学农业农村部草牧业创新重点实验室,兰州大学草地农业教育部工程研究中心,兰州大学草地农业科技学院,甘肃兰州730020 [2]青海大学畜牧兽医科学院/青海省畜牧兽医学院,青海省高寒草地适应性管理重点实验室,青海西宁810016

出　　处：《草地学报》2023年第6期1780-1787,共8页Acta Agrestia Sinica

基　　金：青海省自然基金创新团队项目(2021-ZJ-901);国家自然科学基金面上项目(41671106,32171867);高等学校学科创新引智计划(B12002)资助。

摘　　要：土壤微生物是土壤养分释放或固持的重要调节者。本实验以青藏高原高寒草原为研究对象,以藏羊放牧强度控制实验为平台(对照(CK,0),轻度放牧(LG,2 sheep·hm^(-2)),中度放牧(MG,4 sheep·hm^(-2)),重度放牧(HG,6 sheep·hm^(-2))),开展不同放牧强度下高寒草地土壤和微生物养分变化特征及其对土壤微生物养分代谢的影响研究。结果显示:总体上,土壤碳氮磷含量在放牧干扰下呈减少趋势,而微生物碳氮磷含量及其化学计量的变化幅度较小;重牧的碳获取酶(β-葡萄糖苷酶)活性及化学计量显著高于其余处理。此外,中牧和重牧的C∶P不平衡和N∶P不平衡高于CK,而C∶N不平衡低于CK,这表示在中度或重度放牧下高寒草地主要受到碳、磷的限制。当面对自身与资源之间的养分不匹配时,高寒草地土壤微生物主要通过增加碳获取酶的分泌,来缓解在重牧下的养分限制。Soil microorganisms are important regulators of soil nutrient release and retention.The differences in soil physicochemical properties and soil microorganisms under four grazing intensities of sheep grazing(control blank CK:0,light grazing LG:2 sheep·hm^(-2),moderate grazing MG:4 sheep·hm^(-2),heavy grazing HG:6 sheep·hm^(-2))were investigated,and the effects of different grazing intensities on soil microbial nutrient metabolism were analyzed.The results showed that:in general,the soil carbon(C),nitrogen(N)and phosphorus(P)contents decreased under grazing interference,while the microbial C,N and P contents and their stoichiometry changed a little.The activity and stoichiometry of C-acquiring enzyme(β-glucosidase)in heavy grazing treatment were significantly higher than those in other treatments.In addition,the C∶P imbalance and N∶P imbalance in the moderate and heavy grazing were higher than those of CK,while the C∶N imbalance was lower than that of CK,indicating that moderate or heavy grazing can lead to alpine grassland be relatively limited by carbon and phosphorus.The soil microorganisms mainly balanced the nutrients mismatch between themselves and resources by increasing the C-acquiring enzyme secretion under heavy grazing in alpine grassland.

关 键 词：放牧强度 土壤养分 土壤微生物生物量 土壤酶活性 生态化学计量学 

分 类 号：S812[农业科学—草业科学]