增温对长江源区高寒沼泽草甸优势植物根系分泌物碳输入的影响  

Effects of warming on root exudative carbon inputs of dominant plants in alpine swamp meadows in the headwaters region of the Changjiang River

作　　者：王子龙 白炜[1,2] 房佳辰 马群 牟国旭 WANG Zi-long;BAI Wei;FANG Jia-chen;MA Qun;MOU Guo-xu(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Ministry of Education Engineering Research Center of Water Resource Comprehensive Utilization in Cold and Arid Regions,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070 [2]兰州交通大学寒旱地区水资源综合利用教育部工程研究中心,兰州730070

出　　处：《兰州大学学报（自然科学版）》2024年第6期808-815,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(41877149,41563005);甘肃省自然科学基金项目(21JR7RA319);甘肃省教育厅高校科研创新平台重大培育项目(2024CXPT-14)。

摘　　要：为探究高寒沼泽草甸植物根系分泌物碳输入速率对气候变暖的响应规律,以青藏高原风火山地区高寒沼泽草甸为研究对象,在生长旺季分析增温2.7℃的低增温处理(T_(1))和增温5.1℃的高增温处理(T_(2))对根系分泌物输入速率的动态变化的影响.结果表明,增温促进了优势物种单位根生物量、根长及根表面积碳分泌速率,不同处理间均存在显著差异,3种优势物种单位根生物量与根表面积分泌速率变化趋势一致,表现为T_(2)>T_(1)>对照组;增温显著影响了优势物种根系抗氧化酶的活性,不同物种根系抗氧化酶活性对增温的响应不同,总体而言增温使超氧化物歧化酶活性升高,过氧化氢酶活性降低,且二者均在T_(2)处理下达到峰值;T_(1)和T_(2)处理下高寒沼泽草甸生物量与对照组相比分别提升了72.39%和81.81%;增温显著促进了根系分泌物碳输入及土壤养分转化过程,并且这种影响随增温幅度的升高而增强.增温对3种优势物种根系的碳分泌速率表现出显著的促进作用,加快养分循环过程.To explore the response patterns of root exudation carbon input rates in alpine swamp meadows to climate warming,we focused on the alpine swamp meadows in the Fenghuoshan region of the Qinghai-Xizang Plateau.During the peak growing season,the dynamic effects of different warming gradients(control group(CK);low warming treatment:2.7℃warming(T_(1));high warming treatment:5.1℃warming(T_(2)))on the root exudation carbon input rates were analyzed,and the results indicated that warming promoted the carbon secretion rate of unit root biomass,root length,and root surface area in dominant species,with significant differences existing among the treatments.The trend of unit root biomass and root surface area secretion rate was consistent for the three dominant species,specifically with T_(2)>T_(1)>CK.Warming significantly influenced the antioxidant enzyme activity in the roots of dominant species,which exhibited varied responses in root antioxidant enzyme activity to warming,generally enhancing super oxide dismutase activity and reducing catalase activity,while both reaching maximum or minimum values under high warming conditions.Under the T_(1)and T_(2)treatments,the biomass of the alpine marsh meadow increased by 72.39%and 81.81%,respectively,compared to CK.Warming significantly promoted the carbon input of root exudates and the transformation of soil nutrients.This effect intensified with the increasing magnitude of warming,with the conclusion that warming enhances the carbon secretion rate of the roots of three dominant species,thereby accelerating the nutrient cycling process in the region.

关 键 词：高寒沼泽草甸 增温 根系分泌物 抗氧化酶活性 土壤养分 

分 类 号：S812.2[农业科学—草业科学]