摘要
微生物对环境变化十分敏感,能快速对土壤生态变化作出反应。分析微生物对不同碳源利用能力的差异,明确三江源区高寒草甸土壤微生物群落在不同退化演替阶段的季节变化规律,对草地健康状况评价及可持续利用具有重要意义。采用Biolog-ECO法分析了返青期、生长期和枯黄期不同退化程度(未退化ND,轻度退化LD,中度退化MD,重度退化SD和极重度退化-黑土滩ED)高寒草甸0～10 cm和10～20 cm土层土壤微生物群落对31种碳源的利用特征。结果表明,(1)不同生育期各试验地0～10 cm土壤微生物AWCD值均高于10～20 cm。U指数在返青期0～10 cm和10～20 cm土层间差异不显著,在生长期中度退化和黑土滩草地0～10 cm和10～20 cm土层间均表现显著差异,枯黄期中度退化草地0～10 cm显著高于10～20cm。(2)同一生育期,在0～10cm和10～20cm土层,AWCD值和U指数均以中度退化草地最低。高寒草甸返青期和枯黄期0～10cm土壤微生物AWCD值和U指数均显著低于生长期;而在10～20cm土层,不同生育期间差异不显著。季节和土层交互作用对土壤微生物群落影响显著。(3)微生物群落对6类碳源的相对利用能力表明,同一生育期,随草地退化程度加重,0～10 cm和10～20 cm土壤微生物群落对碳源的相对利用率变化趋势不同。同一时期不同草地相同土层土壤微生物对单一碳源利用率因草地退化程度的不同而表现差异。不同生育期0～10 cm土层土壤微生物群落对6类碳源的利用率差异主要体现在酯类和醇类碳源,而10～20 cm主要体现在糖类和胺类。(4)主成分分析结果表明,在0～10 cm和10～20 cm土层,未退化草地土壤微生物群落对碳源具有较好的利用能力,重度和黑土滩退化草地对碳源的利用能力较为相似,中度退化草地与其他草地相比分异较大;氨基酸类、糖类和胺类碳源对土壤微生物群落起主要分异作用。生长期土壤微生物群落对碳源的利用能力较强,其中糖类、氨基酸类、醇类、羧酸类和胺类具有较大载荷。
Microbes are very sensitive to the environment and can quickly respond to the changes in soil environment.Analyzing the utilization differences of microbes to diverse carbon sources,and clarifying the seasonal variation of soil microbial communities at the alpine meadow in the Three-River-Source area,is crucial to assess the health status of alpine meadow and maintain its sustainable utilization.The utilization of soil microbes in two depth(0~10 cm and 10~20 cm)to 31 carbon sources were examined at three phenological periods(regreening,growing and withering)from alpine meadows under five different degradation degree(non-degradation,ND;light degradation,LD;moderate degradation,MD;severe degradation,SD and extreme degradation-black soil beach,ED).The results showed that:(1)the average color change rate(AWCD)at 0~10 cm was higher than that at 10~20 cm in all meadows at three phenological periods.There was no difference between 0~10 cm and 10~20 cm in Mcintosh index(U)at regreening stage,whereas the differences between two soil layers both in MD and ED at growing stage were significant,and the U index at the soil depth of 0~10 cm in MD was dramatically higher than that at 10~20 cm in withering stage.(2)Within the same phenological period,AWCD and U indexes were the lowest in MD.Soil AWCD and U indexes at the soil depth of 0~10 cm of the regreening and withering periods were significantly lower than those of the growing period,and there was no significant difference among different phenological periods for soil depth of 10~20 cm.Seasons and soil layers had great interacted influence on soil microbial communities.(3)The analysis of relative utilization ability of microbes to six groups carbon sources showed that:in the same growth period soil microbes at 0~10 cm and 10~20 cm had different trends in the carbon sources utilization rate,along degradation stages of alpine meadows.The single carbon source utilization rate in the same period at the same soil layer also varied along the degradation stages.The utilization difference of soil microbes to six groups carbon sources at 0~10 cm in various growth stages was mainly manifested in esters and alcohols carbon sources,while they were mainly affected by carbohydrates and amines at 10~20 cm.And(4)the principal component analysis results showed that:the soil microbes had higher utilization rate for carbon sources at the soil depth of 0~10 cm and 10~20 cm in the ND meadow,and it was similar for the SD and ED meadows.Soil microbial composition in MD meadow was quite different from the other meadows.The amino acids and carboxyl carbon sources may play a major role in the soil microbial differentiation.Soil microbes has strong ability to use carbon sources in the growing period,and sugar,amino acids,alcohols,carboxylic acids and amines had larger loads.
作者
尹亚丽
王玉琴
李世雄
刘燕
赵文
马玉寿
王宏生
温灏宇
YIN Yali;WANG Yuqin;LI Shixiong;LIU Yan;ZHAO Wen;MA Yushou;WANG Hongsheng;WEN Haoyu(State Key Laboratory of Plateau Ecology and Agriculture/Qinghai University Xining 810016,China;Academy of Animal and Veterinary Science,Qinghai University,Xining 810016,China;Qinghai Academy of Animal and Veterinary Science,Xining 810016,China;Northwest A&F University,Yangling 712100,China)
出处
《生态环境学报》
CSCD
北大核心
2018年第10期1791-1800,共10页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(31560660)
青海省科技厅项目(2016-ZJ-729)
关键词
土壤微生物群落多样性
退化高寒草甸
季节变化
碳源利用
soil microbial community diversity
degraded alpine meadow
seasonal variation
carbon sources utilization rate
