植物群落和土壤对人工草地恢复演替的协同响应  

The Synergetic Responses of Plant Community and Soil to the Restorative Succession of Cultivated Grassland

作　　者：潘攀 王长庭 胡雷 刘斯莉 李洁 PAN Pan;WANG Changting;HU Lei;LIU Sili;LI Jie(Institute of Qinghai-Tibetan Plateau,Southwest Minzu University,Chengdu 610225,China;College of Life Science&Technology,Southwest Minzu University,Chengdu 610225,China)

机构地区：[1]西南民族大学青藏高原研究院,四川成都610225 [2]西南民族大学生命科学与技术学院,四川成都610225

出　　处：《生态环境学报》2020年第12期2355-2364,共10页Ecology and Environmental Sciences

基　　金：国家重点研发计划(2019YFC0507701);第二次青藏高原综合科学考察研究项目(2019QZKK0302);国家自然科学基金项目(U20A2008,31870407);中央高校基本科研业务费专项资金重点项目(2020NZD03);西南民族大学研究生“创新型科研项目”重点项目(CX2019SZ92)。

摘　　要：建植人工草地是退化高寒草甸恢复与重建的重要措施之一,但随着建植年限的增加,人工草地会出现逆向演替的转变过程。为了验证人工草地逆向转变的过程并揭示其驱动因子,通过野外调查和室内分析相结合的方法探究了三江源区不同建植期(5、6、9、13 a)人工草地植物群落特征、土壤理化性质和酶活性的变化规律。结果表明:(1)人工草地恢复演替过程中,植物地上生物量、盖度、土壤养分、含水量、酶活性响应趋势一致,呈"N"字型的协同变化规律。植物地上生物量、土壤有机质和含水量在建植9年显著低于其他年份,分别为:281.61 g·m^(-2)、75.67 g·kg^(-1)和7.81%;根土比则呈增加趋势,在建植13年达到最大,为3.58;(2)冗余分析表明,在群落演替过程中植物生物量和盖度呈正相关关系,凋落物和根土比显著正相关,土壤速效磷、速效钾、全磷及酶活性对植物群落的影响最显著(P<0.05);(3)相关性分析结果进一步表明,植物地上生物量、土壤蔗糖酶、脲酶、硝酸还原酶和过氧化氢酶活性均与土壤有机质、全氮及含水量显著正相关,凋落物与土壤速效磷、速效钾及全磷显著正相关,土壤酸性磷酸酶和蔗糖酶活性与土壤pH显著正相关(P<0.05)。综上,地上植物群落和土壤环境因子之间的协同响应与草地恢复演替存在明显的关联性。人工草地恢复演替在建植初期主要由土壤养分和水分主导,随着建植年限的增加,草地正向演替的主控因子由土壤养分和水分逐渐转变为植物根系。Grassland cultivation is one of the effective measures for restoring and reconstructing the degraded alpine meadows in Qinghai-Tibetan Plateau.However,with the increase of cultivation ages,cultivated grassland may change in a reverse direction.In this study,the dynamic changes of plant community characteristics,soil physicochemical properties and enzyme activities in cultivated grasslands at different cultivation years(5 a,6 a,9 a and 13 a)in the Three Rivers source region were investigated by field investigation and laboratory studies.The aims were to elucidate the reverse transformation process of cultivated grasslands and the driving factors.The results showed that:(1)During the succession of cultivated grassland,the above-ground biomass,coverage,soil nutrients,soil water content,enzyme activities all showed the“N”type changing pattern,while the root-to-soil ratio showed an increasing trend.The above-ground biomass,soil organic matter and soil water content in 9 a grassland were 281.61 g·m−2,75.67 g·kg−1 and 7.81%,respectively,and they were significantly lower than those in other planting years.The root-to-soil ratio reached the maximum of 3.58 in planting 13 a.(2)Redundancy analysis indicated that during the succession of cultivated grassland,plant above-ground biomass was positively correlated with coverage,and litter was positively correlated with root-to-soil ratio.Soil available phosphorus,available potassium,total phosphorus and enzyme activities showed most significant effects on plant community(P<0.05).And(3)the correlation analysis results further indicated that aboveground biomass,soil sucrase activities,urease activities,nitrate reductase activities and catalase activities were significantly and positively correlated with soil organic matter,total nitrogen and water content.Litter was significantly and positively correlated with soil available phosphorus,available potassium and total phosphorus.Soil acid phosphatase activities and sucrase activities showed significantly positive correlatio

关 键 词：人工草地 建植年限 植物群落 土壤环境 协同响应 

分 类 号：Q948[生物学—植物学] X17[环境科学与工程—环境科学]