黄土高原刺槐林土壤化学计量特征和微生物元素利用效率的季节差异  

Seasonal differences of soil stoichiometric characteristics and microbial element utilization efficiency in Robinia pseudoacacia forest on the Loess Plateau

作　　者：段露露 乔芷瑛 袁艳红 汪莉 吴铎 赵发珠 任成杰[3] 郭垚鑫 王俊[1,2,5] DUAN Lulu;QIAO Zhiying;YUAN Yanhong;WANG Li;WU Duo;ZHAO Fazhu;REN Chengjie;GUO Yaoxin;WANG Jun(Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Northwest University,Xi′an 710127,China;College of Urban and Environment Science,Northwest University,Xi′an 710127,China;Northwest Agriculture and Forestry University,Yangling 712100,China;College of Life Science,Northwest University,Xi′an 710127,China;Shaanxi Key Laboratory for Carbon Neutral Technology,Xi′an 710127,China)

机构地区：[1]陕西省地表系统与环境承载力重点实验室,西安710127 [2]西北大学城市与环境学院,西安710127 [3]西北农林科技大学,杨凌712100 [4]西北大学生命科学学院,西安710127 [5]陕西省碳中和技术重点实验室,西安710127

出　　处：《生态学报》2024年第15期6584-6596,共13页Acta Ecologica Sinica

基　　金：国家自然科学基金面上项目(42377345);西北大学大学生创新创业项目(202310697075)。

摘　　要：为探究刺槐人工林根际和非根际土壤微生物元素利用效率的季节差异及其影响因素,在黄土高原选取3个季节(春季、夏季、秋季)人工林根际和非根际土壤为研究对象,测定土壤理化性质、微生物生物量和酶活性等指标,计算化学计量失衡、矢量特征及元素利用效率。结果表明,季节动态显著影响化学计量失衡,根际和非根际C∶N失衡在季节上均表现为先增加后降低的趋势,而C∶P和N∶P失衡则相反。矢量长度和矢量角度的变化表明根际与非根际土壤微生物均在夏季受到较强的碳、氮限制,而在春、秋季受到较强的磷限制。季节动态对微生物元素利用效率有显著影响,其中碳利用效率在夏季最低,而氮、磷利用效率在夏季最高。偏最小二乘路径模型结果表明,根际和非根际土壤微生物均通过矢量特征和胞外酶活性间接地影响元素利用效率,而非根际土壤微生物化学计量失衡对元素利用效率有直接影响。研究结果有助于深入理解人工林根际和非根际土壤微生物的养分利用机制,为生态脆弱地区的人工林管理提供理论依据。To investigate the seasonal dynamics and influencing factors of soil stoichiometric characteristics and microbial elements use efficiency in the rhizosphere and bulk soils,the rhizosphere and bulk soils of Robinia pseudoacacia plantations in three seasons(Spring,Summer,and Autumn)were selected as the study objects on the Loess Plateau.Soil physicochemical properties,microbial biomass,and enzyme activity were determined,and stoichiometric imbalance,vector characteristics,and element use efficiency were calculated.Combined with Partial least squares path model analysis of various related environmental factors,this study investigates the seasonal variation mechanism of microbial element utilization efficiency in rhizosphere and bulk soils.The results showed that the seasonal dynamics significantly influenced stoichiometric imbalance,with both rhizosphere and bulk soils C∶N imbalance showing an increase trend followed by decrease across seasons,reaching its maximum value in summer(0.91,3.22).While C∶P and N∶P imbalances exhibited the opposite pattern.The VL of rhizosphere and bulk soils are highest in summer,while VA are greater than 45°in spring and autumn,and less than 45°in summer.Changes in VL and VA indicated that soil microorganisms in both rhizosphere and bulk soils experienced stronger carbon and nitrogen limitations in summer,and stronger phosphorus limitation in spring and autumn.The seasonal dynamics have a significant impact on the utilization efficiency of microbial elements,with carbon utilization efficiency being the lowest in summer,with an average of about 0.33,and nitrogen and phosphorus utilization efficiency being the highest in summer.This indicates that rhizosphere soils microorganisms have a stronger contribution to carbon fixation in spring and autumn,while bulk soils microorganisms have a stronger contribution to nitrogen and phosphorus fixation in summer.The results of the partial least squares path model indicate that the factors affecting soil element utilization efficiency include

关 键 词：根际和非根际 化学计量失衡 胞外酶 资源限制 元素利用效率 黄土高原 

分 类 号：S714[农业科学—林学] S792.27