岷江源区高山林草交错带土壤碳、氮、磷生态化学计量关系的时空变化  

Spatial and temporal variations in soil C,N,and P ecological stoichiometry across the alpine forests and grassland ecotone at the Minjiang Headwaters

作　　者：何家莉 宋怡珂 王金牛[1] 周俊[3] 王春雅 查琳 石凝 吴彦[1] 白景文 HE Jiali;SONG Yike;WANG Jinniu;ZHOU Jun;WANG Chunya;ZHA Lin;SHI Ning;WU Yan;BAI Jingwen(Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;College of Life Science,Sichuan Normal University,Chengdu 610101,China;Chengdu Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China;College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou 730070,China;College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China;College of Forestory,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]中国科学院成都生物研究所,成都610041 [2]四川师范大学生命科学学院,成都610101 [3]中国科学院水利部成都山地灾害与环境研究所,成都610041 [4]甘肃农业大学资源与环境学院,兰州730070 [5]成都理工大学地球科学学院,成都610059 [6]四川农业大学林学院,成都611130

出　　处：《应用与环境生物学报》2021年第4期869-877,共9页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(41661144045,31971436);中国科学院西北生态环境与资源研究院冰冻圈国家重点实验室开放课题(SKLCSOP-2018-07)资助。

摘　　要：高山林草交错带(alpine forest-grassland ecotone)作为响应气候变化极为敏感剧烈的地带之一,研究该区域短暂生长季内土壤养分的时空动态变化,有助于理解高山植物生长发育过程中的土壤-植物界面互作过程以及植被分布格局.选取岷江源3处高山林草交错带植物生长季内的土壤样品,分析其养分的动态变化以了解该区域土壤养分对植物生长的供给状况.通过生物地理界线沿海拔从高到低将交错带划分为树种线、树线和密闭森林,并分别于植物生长初期、生长盛期和生长末期在相同样点采集0-20 cm土样.比较分析土壤中总碳、总氮、总磷、有机碳以及水分含量,结果表明土壤养分受生长期阶段和生物地理界线及其交互作用的显著影响.植物从生长初期进入到生长末期,土壤养分含量逐渐减少,其中密闭森林区养分吸收消耗最多.生长季交错带内土壤理化指标变化范围为TC含量15-195 g/kg,TN含量2-11g/kg,TP含量0.2-1.0g/kg,SOC含量5-96g/kg,SWC含量16-64%.土壤化学计量比的值随时间增大,C/N为25-75,C/P为25-90,N/P为5-75.土壤养分和水分在生长盛期有显著相关关系,且该时期各养分间的相关系数最大.上述研究表明,植被类型和植物生长速率对下方土壤养分含量有极显著影响;土壤生态化学计量比在植物生长季具有很大波动;高温、高降水及快速的植物生长可以提高土壤养分间的正相关关系.The alpine forest-grassland ecotone is one of the zones most sensitive in response to climate change.Understanding the temporal and spatial distribution of soil nutrients in this area is helpful for understanding the biogeochemical cycle processes at the soil-plant interface.This study aimed to determine the relationship between soil C,N,and P levels and other physical and chemical indicators as well as ecological stoichiometric ratios under different biogeographic boundaries in an alpine ecosystem.The temporal and spatial distribution patterns of soil total carbon(TC),total nitrogen(TN),total phosphorus(TP),organic carbon(SOC),and soil water content(SWC)in the 0-20 cm soil layer were evaluated at the early growth stage,peak growth stage,and end of the growth stage of three alpine forest-grassland ecotones in the Minjiang Headwaters region.From the beginning to the end of the growing season,the soil nutrient content decreased gradually.In the growing season,the TC,TN,TP,SOC,and SWC levels in the alpine forest-grassland were 15-195 g/kg,2-11 g/kg,0.2-1.0 g/kg,5-94 g/kg,and 16%-64%,respectively,whereas the range of soil ecological stoichiometric ratios increased,that is,C/N,25-75;C/P,25-90;and N/P,5-75.There were significant correlations between soil nutrients and water content at the peak growth stage,with the highest correlation coefficient.Vegetation type and plant growth have a significant effect on soil physical and chemical indicators.The stoichiometric ratio of soil ecology fluctuated greatly during the growing season.The coupling between temperature,precipitation,and plant growth can improve the positive effects of biogeochemical cycling.

关 键 词：高山树线 生长季 养分含量 生物地理界线 生物地化循环 

分 类 号：S714[农业科学—林学]