辽东栎林次生演替过程中土壤酶化学计量特征变化  

Changes of soil enzyme activity and their stoichiometric characteristics during secondary succession of Quercus liaotungensis forests

作　　者：闫本帅 孙利鹏 李晶晶 高利强 乔占国 高小峰 吴春晓 王国梁 YAN Ben-shuai;SUN Li-peng;LI Jing-jing;GAO Li-qiang;QIAO Zhan-guo;GAO Xiao-feng;WU Chun-xiao;WANG Guo-liang(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,Shaanxi,China;Yulin University,Yulin 7190Q0,Shaanxi,China;Yulin Institute of Forestry,Yulin 719000,Shaanxi,China)

机构地区：[1]西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]榆林学院,陕西杨凌712100 [3]榆林市林业科学研究所,陕西杨凌719000 [4]中国科学院水利部水土保持研究所,陕西杨凌719000

出　　处：《生态学杂志》2022年第4期641-647,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金专项项目(42041005-3B);国家自然科学基金项目(42077456)资助。

摘　　要：土壤胞外酶驱动地下生态系统的养分循环等过程,而目前土壤酶活性随着植被次生演替的变化机制尚不明确。本文采用空间代替时间的方法,选取陕西富县的农田为对照,研究了30、60和120年生辽东栎林土壤酶活性及其化学计量的变化以及驱动因子(植被特征、土壤物理化学特征、微生物生物量)。结果表明:随着演替的进行,β-1,4-葡萄糖苷酶(BG)、β-N-乙酰氨基葡萄糖苷酶(NAG)及亮氨酸氨肽酶(LAP)活性显著增加,而碱性磷酸酶(AP)活性先增加后减小然后再增加,在120年生林地达到最大值,BG、LAP+NAG及AP酶活性分别为25.96~40.96、57.10~128.05、65.41~126.60 nmol·g^(-1)·h^(-1)。农田土壤的BG/(LAP+NAG)和BG/AP大于30年生林地,而(LAP+NAG)/AP呈相反的趋势。农田土壤微生物代谢主要受C和P养分的限制;而随着演替的进行,BG/(LAP+NAG)逐渐增加,(LAP+NAG)/AP和BG/AP先增加而后减小,从而缓解C和P养分对微生物代谢的限制,但造成N养分限制。冗余分析表明,土壤微生物量P、铵态氮及根系生物量是植被次生演替过程中土壤酶活性及其化学计量比变化的主要驱动因子。总之,植被演替通过影响土壤养分含量改变微生物代谢,并对土壤养分循环过程产生影响。Soil extracellular enzymes play an important role in soil nutrient cycling.However,the mechanism underlying the changes of soil enzymes during vegetation succession is not clear.In this study,on the basis of substituting space for time,cropland and Quercus liaotungensis forests after 30,60 and 120 years restoration were selected as research objects to examine the changes and driving factors(vegetation and soil physicochemical characteristics,and microbial biomass)of soil enzyme activities and their stoichiometry in the process of secondary succession in Fuxian County,Shaanxi Province.Across the chronosequence,the activities ofβ-1,4-glucosidase(BG),β-1,4-N-acetylglucosaminidase(NAG),and leucine aminopeptidase(LAP)showed an increasing trend,that of alkaline phosphatase(AP)first increased,then decreased and then increased,reaching a maximum value after 120 years of vegetation restoration.The activities of BG,LAP+NAG and AP ranged 25.96-40.96,57.10-128.05,65.41-126.60 nmol·g^(-1)·h^(-1),respectively.BG/(LAP+NAG)and BG/AP in the cropland were higher than those in the 30-year-old forest,while(LAP+NAG)/AP showed an opposite trend.In the cropland,soil microbial metabolism was mainly limited by C and P.With vegetation succession,BG/(LAP+NAG)increased gradually,and(LAP+NAG)/AP and BG/AP increased first and then decreased,indicating that the limitation of C and P on microbial metabolism was alleviated and shifted to N limitation.RDA results showed that soil enzyme activities and their stoichiometry were mainly affected by soil microbial biomass,ammonium nitrogen,and root biomass during the secondary succession.In conclusion,vegetation succession alters microbial metabolism by affecting soil nutrient content,with consequences on soil nutrient cycling.

关 键 词：土壤酶活性 酶化学计量比 养分限制 向量分析 

分 类 号：S714.3[农业科学—林学]