干旱背景下土壤酶活性对石砾含量变化的响应  

Response of soil enzyme activity to changes in rock fragment content under drought condition

作　　者：黄龙 胡慧 包维楷[1] 李芳兰[1] 胡斌[1] HUANG Long;HU Hui;BAO Weikai;LI Fanglan;HU Bin(CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院成都生物研究所,中国科学院山地生态恢复与生物资源利用重点实验室,生态恢复与生物多样性保育四川省重点实验室,成都610041 [2]中国科学院大学,北京100049

出　　处：《应用与环境生物学报》2021年第2期294-302,共9页Chinese Journal of Applied and Environmental Biology

基　　金：国家重点研发计划项目(2017YFC0505105);国家自然科学基金面上项目(31470478)资助。

摘　　要：人为活动干扰导致的土壤石砾增加将引起土壤结构及水文过程变化,从而影响土壤生物学特征.土壤酶活性是重要的土壤生物学特征之一,与土壤养分循环紧密相关,然而石质含量变化梯度上土壤酶活性的变化规律与机制不清楚.为探明土壤酶活性对石砾含量变化的响应及机制,在岷江干旱河谷通过半控制试验设置4个石砾体积含量梯度(0%、25%、50%和75%,V/V),比较分析5种土壤酶活性随石砾含量和土层的变化特点,多元统计分析揭示石砾含量梯度上影响胞外酶活性的关键土壤因子.发现所有土壤酶活性在不同石砾含量处理之间存在显著差异,而水解酶在土层之间具有显著差异,但石砾含量与土层交互作用对酶活性无显著影响.土壤中高石砾含量(75%)可抑制水解酶活性,并且降低不同土层之间酶活性的差异.在无石砾(0%)和低石砾(25%)处理下,各土层中水解酶活性具有先增加后减少的变化规律,而在中等(50%)和高石砾含量条件下,不同土层酶活性垂直变化较小.土壤水分和有效磷与所有土壤酶活性呈显著正相关,而pH和铵态氮与部分土壤酶活性呈显著负相关.主成分分析结果显示,前两个轴解释了总变异的70.3%,其中PC1轴解释了59%的变异.本研究结果表明土壤养分和水分是影响土壤酶活性的主要因子,并且低石砾含量土壤中养分、水分与酶活性之间的关联更加紧密;结果可为阐明土壤结构与功能的关系提供新证据以及为石质土壤的生物改良提供科学指导.(图4表3参54)Increased soil rock fragments due to anthropogenic disturbances will cause changes in soil structure and hydrological processes,which may lead to changes in soil biological characteristics.Soil enzyme activity is an important biological characteristic of soil and is closely related to soil nutrient cycling.However,changes in soil enzyme activities with rock fragment content and mechanisms driving these changes remain unclear.To investigate the effect of rock fragments on soil enzyme activity,a semi-controlled experiment with four rock fragment content(RFC)treatments(0%,25%,50%,and 75%,V/V)in the dry valley of the Minjiang River,Sichuan Province,China was conducted.The effect of RFC on the activities of five soil enzymes in different soil layers was compared and analyzed.Multivariate statistical analyses were used to determine key soil factors affecting extracellular enzyme activities across all treatments.We found that RFC significantly affected all soil enzyme activities,whereas soil layer only affected hydrolase activity.However,there was no interactive effect between RFC and soil layer on soil enzyme activities.High RFC decreased the activity of hydrolase and reduced the difference in enzyme activity between the different soil layers.Hydrolase activity first increased and then decreased with soil depth in the 0%and 25%RFC treatments.Soil enzyme activities were not significantly different between the different soil layers in the 50%and 70%RFC treatments.All enzyme activities had a significant positive correlation with soil water content and available phosphorus,whereas certain enzyme activities had a significant negative correlation with pH and ammonium nitrogen.Principal component analysis showed that the first two axes accounted for 70.3%of the total variation,and the PC1 axis accounted for 59%of the variation.The results of this study demonstrate that soil nutrients and soil water were the key factors affecting soil enzyme activity.Moreover,both soil nutrients and soil water were more closely related to soil

关 键 词：石砾含量 胞外酶活性 土壤养分 土壤水分 微生物生物量 干旱河谷 

分 类 号：S154.2[农业科学—土壤学]