湘中丘陵区4个树种人工纯林土壤-微生物-胞外酶C∶N∶P化学计量特征  

Soil-microbe-exoenzyme C∶N∶P Stoichiometric Characteristics in Artificial Pure Forests of Four Tree Species in the Hilly Region of Central Hunan

作　　者：卢巧露 方晰[1,2] 范世才 孙龙 孙百慧 梁婷婷 李毅 LU Qiaolu;FANG Xi;FAN Shicai;SUN Long;SUN Baihui;LIANG Tingting;LI Yi(College of Life and Environmental Sciences,Central South University of Forestry and Technology,Changsha 410004,China;Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province,Huitong,Hunan 438107,China)

机构地区：[1]中南林业科技大学生命与环境科学学院,长沙410004 [2]湖南会同杉木林生态系统国家野外科学观测研究站,湖南会同438107

出　　处：《水土保持学报》2025年第1期239-248,共10页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(U23A20154)。

摘　　要：[目的]不同树种人工林因养分吸收利用策略的差异,导致土壤碳(C)、氮(N)、磷(P)质量分数及其化学计量比的改变显著影响土壤微生物活性,土壤微生物是否通过调整自身生物量和胞外酶化学计量比适应土壤的变化仍不明确。为探究不同树种人工林对土壤微生物生物量和胞外酶活性的影响,研究土壤-微生物-胞外酶C∶N∶P化学计量比之间的协变性。[方法]以湘中丘陵区土壤发育、经营历史一致,不同生活型的4个树种[针叶树马尾松(Pinus massoniana)、落叶阔叶树枫香(Liquidaar formosana)、常绿阔叶树木荷(Schima superba)和杜英(Elaeocarpus decipiens)]人工林作为研究对象,测定0~40 cm土层C、N、P质量分数,微生物生物量碳(C_(mic))、氮(N_(mic))、磷(P_(mic))和微生物获取C(β-1,4-葡萄糖苷酶+β-纤维二糖苷酶,BG+CBH)、N(β-1,4-N-乙酰氨基葡萄糖苷酶,NAG)、P(酸性磷酸酶,ACP)资源的相关胞外酶活性(EEA)。[结果]1)不同树种人工林显著影响土壤C、N、P质量分数,微生物生物量,胞外酶活性及C_(mic)∶N_(mic)∶P_(mic)和EEAC∶N∶P;马尾松林、枫香林C_(mic)∶P_(mic)显著高于木荷林和杜英林,微生物与植物竞争土壤有效P,土壤P利用率低,特别是枫香林;木荷林NAG及EEAN∶P最高,微生物受N限制明显;杜英林ACP较高,且EEAC∶N、EEAC∶P也高于其他树种人工林,而EEAN∶P最低,微生物受C、P限制最为严重。2)土壤C∶N∶P与微生物生物量、胞外酶C∶N∶P相关性不显著,仅有C_(mic)∶N_(mic)与EEAC∶N、C_(mic)∶P_(mic)与EEAC∶P呈显著负相关,表明土壤C∶N∶P与微生物生物量C∶N∶P不存在协变性;而土壤C∶N∶P与C∶P_(imb)呈显著正相关,C_(mic)∶N_(mic)∶P_(mic)与C∶N∶P_(imb)呈显著负相关,C∶N_(imb)和EEAC∶N呈显著正相关,证实土壤与微生物间C、N、P的差异对胞外酶化学计量比的影响。3)凋落物层现存量对土壤C、N、P质量分数及P_(mic)、C_(mic)∶P_(mic)�[Objective]The contents of soil carbon(C),nitrogen(N)and phosphorus(P)along with their stoichiometric ratios are varied due to the varying nutrient uptake and utilization strategies among plantations of various tree species,which in turn can affect soil microbial activity.However,whether soil microorganisms adapt to these changes by adjusting their biomass and extracellular enzyme stoichiometric ratios remains uncertain.This study aims to explore the effects of plantations of various tree species on soil-microbe-exoenzyme C∶N∶P stoichiometric ratios and to investigate the correlations among soil-microbe-exoenzyme stoichiometry.[Methods]An investigation into the contents of C,N and P,as well as microbial biomass C(C_(mic)),N(N_(mic)),and P(P mic)was conducted,and the activities of C-(β-1,4-glucosidase+β-D-cellosidase,BG+CBH),N-(β-1,4-N-acetylglucosaminidase,NAG),and P-(acid phosphatase,ACP)acquiring extracellular enzymes for microorganisms at 0—40 cm depth in four native tree species plantations were determined.These plantations included conifers Pinus massoniana,deciduous broad-leaved Liquidambar formosana,Devergreen broad-leaved Schima superba and Elaeocarpus decipiens located in the hilly region of central Hunan Province and shared a common soil development and management history.[Results]1)Plantations of different tree species significantly affected soil C,N,P contents,microbial biomass,extracellular enzyme activity;C_(mic)∶N_(mic)∶P mic and EEA C∶N∶P.C_(mic)∶P mic ratios in P.massoniana plantations and L.formosana plantations were significantly higher than those in S.superba plantations and E.decipiens plantations,indicating that microorganisms competed with plants for soil available P.The utilization rate of soil P was low,especially in L.formosana plantations.NAG and EEA N∶P in S.superba plantations were the highest,suggesting that microorganism were obviously limited by N there.ACP in E.decipiens plantations was higher,EEA C∶N and EEA C∶P were also higher than those in plantations

关 键 词：化学计量比 微生物生物量 胞外酶活性 针叶树 落叶阔叶树 常绿阔叶树 

分 类 号：S714.1[农业科学—林学]