湘中丘陵区4种森林类型土壤微生物生物量碳氮含量  

Soil Microbial Biomass Carbon and Nitrogen Concentrations in Four Subtropical Forests in Hilly Region of Central Hunan Province,China

作　　者：李胜蓝[1,2] 方晰[1,2] 项文化[1,2] 孙伟军[1,2] 张仕吉[1] 

机构地区：[1]中南林业科技大学生命科学与技术学院,长沙410004 [2]南方林业生态应用技术国家工程实验室,长沙410004

出　　处：《林业科学》2014年第5期8-16,共9页Scientia Silvae Sinicae

基　　金：国家林业局林业公益性行业科研专项项目(201304317);国家自然科学基金项目(31170426);湖南省科技厅项目(2011SK3120)

摘　　要：采用氯仿熏蒸浸提法,比较湘中丘陵区4种不同森林类型（杉木人工林、马尾松＋石栎针阔混交林、南酸枣落叶阔叶林、石栎＋青冈常绿阔叶林）土壤微生物生物量碳和氮含量及其季节动态变化,分析土壤微生物生物量碳氮含量与土壤养分含量、含水率的相关性.结果表明：4种森林各层土壤总有机碳、全氮平均含量的变化趋势基本一致,呈现出随着林分组成树种数量的增加而增大;南酸枣落叶阔叶林和青冈＋石栎常绿阔叶林各土层土壤微生物生物量碳和氮含量均高于马尾松＋石栎针阔混交林和杉木人工林,且以南酸枣落叶阔叶林最高,杉木人工林最低;土壤微生物生物量碳含量占土壤总有机碳含量的2.3％ ～2.9％,土壤微生物生物量氮含量占全氮含量的4.5％ ～6.4％,均以南酸枣落叶阔叶林最高,马尾松＋石栎针阔混交林最低;4种森林土壤微生物生物量碳和氮含量的季节变化均表现为“单峰曲线型”,呈现出“夏高冬低”型或“秋高春低”型,杉木人工林、马尾松＋石栎针阔混交林土壤微生物生物量碳含量季节波动幅度较其他2种森林明显,但其土壤微生物生物量氮含量季节波动幅度没有其他2种森林明显;土壤微生物生物量碳、氮含量与土壤总有机碳、全氮、碱解氮含量之间均极显著正相关（P＜o.o1）,但与土壤含水率不存在显著的相关性（P＞0.05）,初步揭示该地区4种森林土壤微生物生物量碳和氮含量的季节变化不直接受控于土壤自然含水率,4种森林与环境因子长期共同作用导致土壤总有机碳和全氮含量的差异是影响不同森林土壤微生物生物量碳和氮含量差异及其季节动态变化的主要因素之一.A chloroform fumigation extraction method was used to investigate seasonal variations in microbial biomass carbon and microbial biomass nitrogen concentration in four forests （i.e.Cunninghamia lanceolata plantation,Pinus massoniana ＋ Lithocarpus glaber mixed forest,Choerospondias axillaris deciduous broad-leaved forest,and L.glaber ＋ Cyclobalanopsis glauca evergreen broad-leaved forest） in middle hilly region of Hunan Province.Correlation analyses were performed on soil microbial biomass carbon and nitrogen concentration against soil nutrients and moisture.The results showed that the average concentration of total soil organic carbon and total nitrogen in all soil layers were similar and increased with increase in the tree species richness in stands.The concentrations of microbial biomass carbon and nitrogen were higher in C.axillaris deciduous stand and L.glaber ＋ C.glauca evergreen broad-leaved stand than that in P.massoniana ＋ L.glaber mixed stands and C.lanceolata plantations.The highest concentrations of microbial biomass carbon and nitrogen occurred in C.axillaries deciduous stand while the lowest concentrations occurred in C.lanceolata plantation.The ratios of microbial biomass carbon to total organic carbon and microbial biomass nitrogen to total nitrogen were highest in C.axillaris deciduous stand,and lowest in P.massoniana ＋ L.glaber mixed stand,ranging from 2.3％-2.9％ and 4.5％-6.4％,respectively.The seasonal variations in concentrations of microbial biomass carbon and nitrogen displayed a single peak （the highest value was in summer while the lowest value was in winter,or the highest value was in autumn while the lowest value was in spring）.The seasonal fluctuation amplitude of microbial biomass carbon in P.massoniana ＋ L.glaber mixed forest,C.lanceolata plantation were significantly different compared with other two forests,but there was no significant difference in microbial biomass nitrogen; There were positive and significant （P ＜ 0.05） correlations between soil micr

关 键 词：湘中丘陵区 杉木人工林 演替阶段 天然次生林 土壤微生物生物量碳氮含量 

分 类 号：S718.5[农业科学—林学]