三工河流域不同植物群落细根对盐碱化的响应  

Response of the fine roots of different plant communities to salinity in the Sangong River basin

作　　者：汪依妮 柳鑫 王健健[2] 田思惠 田晓龙 赵学春 WANG Yini;LIU Xin;WANG Jianjian;TIAN Sihui;TIAN Xiaolong;ZHAO Xuechun(College of Animal Science of Guizhou University,Guiyang 550025,China;College of Life Science of Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学动物科学学院,贵阳550025 [2]贵州大学生命科学学院,贵阳550025

出　　处：《应用与环境生物学报》2018年第6期1229-1235,共7页Chinese Journal of Applied and Environmental Biology

基　　金：贵州省科技厅-贵州大学联合基金项目(黔科合LH字[2017] 7288号);国家自然科学基金地区项目(31560670);贵州大学人才引进项目(贵大人基合字[2014] 13号)资助~~

摘　　要：采用连续土钻取样和分解袋分解法,对三工河流域5个不同盐碱化植物群落(琵琶柴群落、骆驼刺群落、沙枣群落、多枝柽柳群落、芦苇群落)整个生长季节的细根垂直分布、季节变化、分解动态、周转规律及其与土壤因子的关系进行研究.结果表明,细根生物量随土层深度的增加均呈现先增加后逐渐降低的趋势,除芦苇群落外,均在10-20cm土层达到最大值;5个群落的细根生物量分别为51.55、93.09、146.24、57.95、419.34 g/m2,随季节变化均呈现先增加后降低的趋势,在8月或9月达到峰值;在5个月的细根分解试验中,5个群落的细根分解速率呈现快、慢、快3个明显的阶段,分解速率属Peterson划分的慢组;不同群落的细根死亡量、年分解量和净生产力差异显著,三者均表现为芦苇群落>沙枣群落>骆驼刺群落>多枝柽柳群落>琵琶柴群落;5个群落的细根周转速率范围为1.41-1.98次/年,高于陆地生态系统细根的周转速率0.56次/年;逐步回归分析表明土壤pH、土壤电导率、土壤容重、土壤含水量是影响各变量的主要因子或共同主要因子,土壤pH是影响根系分布、分解和周转的最主要因素.因此,盐碱植物群落细根生物量小,分解慢而周转快,土壤水盐特征决定了细根的分布和动态.Throughout the whole growing season (from May to October 2010), sequential soil coring and ingrowth bag methods were adopted to investigate the vertical distribution, seasonal changes, decomposition dynamics, and turnover of fine roots, and their relationship with soil factors of five saline-alkali plant communities (Reaumuria songonica community, Alhagi sparsifolia community, Elaeagnus angustifolia community, Tamarix ramosissima community, and Phragmites australis community) in the Sangong River basin. Results showed that the fine root biomass increased initially, and decreased thereafter as soil layers deepened in the five studied communities. The fine root biomass reached its maximum in the 10–20-cm soil layer in all communities, except for P. australis. The fine root biomass of all five communities initially increased, but decreased thereafter from May to October, reaching its maximum in August or September, with values of 51.55, 93.09, 146.24, 57.95, and 419.34 g/m2, respectively. The fine root decomposition rate presented three distinct “fast-slow-fast” phases over the five-month long decomposition experiment, and all five decomposition rates were divided into the “slow group” of Peterson. The amount of fine root death, fine root decomposition, and fine root productivity were significantly different between communities: P. australis community > E. angustifolia community > A. sparsifolia community > T. ramosissima community > R. soongonica community. The range of fine root turnover rate was 1.41–1.98 times/a in the five communities, higher than the average value of 0.56 times/a observed in terrestrial ecosystems. Stepwise regression analysis showed that the soil pH, soil electrical conductivity, soil bulk density, and soil water content were the dominant factors or common dominant factors, and that the soil pH was the most important factor influencing the fine root distribution, decomposition, and turnover. Saline communities have a small fine root biomass, a slow decomposition rate, and a fast t

关 键 词：荒漠植物群落 盐碱化 细根动态 土壤容重 土壤含水量 

分 类 号：Q948.113[生物学—植物学]