秦岭3种天然林细根分布特征及其与土壤理化性质的关系  

Characterization of Fine Roots Distribution in Three Natural Forests of Qinling Mountains and Their Relations with Soil Physical and Chemical Properties

作　　者：祝乐 许晨阳 耿增超 刘莉丽[3] 侯琳[3] 王志康 王强 陈树兰 李倩倩 Zhu Le;Xu Chenyang;Geng Zengchao;Liu Lili;Hou Lin;Wang Zhikang;Wang Qiang;Chen Shulan;Li Qianqian(Key Laboratory of Plant Nutrition and Agri-Environment in Northwest China, Ministry of Agriculture College of Natural Resources and Environment, Northwest A&F University Yangling 712100;Key Laboratory for Agricultural Environment, Ministry of Agriculture ,Beijing 100081;College of Forestry, Northwest A&F University ,Yangling 712100)

机构地区：[1]西北农林科技大学资源环境学院农业部西北植物营养与农业环境重点实验室,杨凌712100 [2]农业部农业环境重点实验室,北京100081 [3]西北农林科技大学林学院,杨凌712100

出　　处：《林业科学》2020年第2期24-31,共8页Scientia Silvae Sinicae

基　　金：国家林业公益性行业科研专项(201304307);农业部农业环境重点实验室开放基金(K4030217149)

摘　　要：【目的】研究秦岭3种天然林细根分布特征及其与土壤理化性质的关系,为秦岭地区生态治理和森林恢复提供科学依据。【方法】采用土柱法对秦岭辛家山林区云杉林、红桦林及云杉+红桦混交林3种天然林进行根系取样,分析细根生物量密度、细根根长密度、细根体积、细根比根长与土壤有机质含量、孔隙度、密度、硝态氮含量、铵态氮含量和湿度的关系。【结果】随土壤深度增加,3种天然林土壤的有机质含量、孔隙度、硝态氮含量、铵态氮含量和湿度均降低,但密度升高;随土壤深度增加,3种天然林各细根指标均降低,其中细根生物量主要集中在腐殖质层,各林分在腐殖质层的占比均大于69%;腐殖质层具有最高的细根根长密度、细根体积和细根比根长,分别是淀积层的3.76~4.85、2.63~3.80和1.26~1.67倍,分别是母质层的11.13~14.98、6.32~16.01和1.76~3.28倍;3种天然林中,混交林各土层的细根根长密度最高(平均值为0.45 cm·cm-3),云杉林各土层的细根根长密度、细根体积和细根比根长最低(平均值分别为0.26 cm·cm-3、0.88 mm-3·cm-3和0.60 cm·g-1);相关性分析表明,3种天然林分各细根指标与土壤的有机质含量、孔隙度、密度、硝态氮含量、铵态氮含量和湿度均呈极显著或显著相关,其中细根生物量密度、细根根长密度、细根体积与土壤有机质含量的正相关性最高(r值分别为0.813、0.795和0.784),与土壤密度的负相关性最高(r值分别为-0.715、-0.658和-0.683);主成分分析表明,影响细根分布的第一主成分因子包括土壤有机质含量、硝态氮含量、密度、孔隙度、湿度和铵态氮含量;通径分析表明,土壤有机质含量对细根生物量密度的直接正效应最高,土壤湿度的间接效应最高且主要是通过有机质含量的间接效应来实现。【结论】秦岭3种天然林的细根指标均随土壤深度增加而减少,土壤腐殖质层为【Objective】To further understand the role of fine roots in forest soil,the distribution of fine roots in three natural forests of Qinling Mountains and their relationships with soil physical and chemical properties were characterized in order to provide a scientific baseis for ecological management and forest restoration in Qinling Mountains.【Method】Soil columns were sampled from three natural forests of Qinling Mountains,namely Picea asperata forest,Betula albo-sinensis forest and mixed forest of P.asperata and B.albo-sinensis.The relations between root parameters(fine root biomass,fine root length density,fine root volume and fine specific root length)and soil properties(soil organic matter,soil porosity,soil density,soil nitrate nitrogen,soil ammonium nitrogen and soil moisture)were studied.【Result】Soil physical and chemical properties of the three natural forests showed vertical stratification along the soil profile.The organic matter content,porosity,nitrate content,ammonium content and moisture all decreased with increasing soil depth.Soil density increased with the increase of soil depth.The fine root indexes of the three natural forests decreased with the increase of soil depth.Fine root biomass mainly concentrated in humus layer,auouating for more than 69%in the humus layer for all the three natural forests,which also had the highest fine root length density,fine root volume and fine specific root length,where was 3.76-4.85,2.63-3.80,1.26-1.67 times as high as that in illuvial layer,and 11.13-14.98,6.32-16.01,1.76-3.28 times as high as that in parent material layer.Among the three forest stands,the fine root length densities in layers of mixed forest were the highest(its mean value was 0.45 cm·cm-3);the fine root length density,fine root volume,and specific fine root length in layers of the P.asperata forest were the lowest(the mean value were 0.26 cm·cm-3,0.88 mm-3·cm-3,0.60 cm·g-1respectively).The result of correlation analyses showed that there were extremely significant or significant

关 键 词：天然林 细根 分布特征 土壤性质 

分 类 号：S714[农业科学—林学]