秦岭天然林凋落物去除对土壤团聚体稳定性及细根分布的影响  

Effects of litter removal on soil aggregate stability and distribution of fine roots in natural forests of Qinling Mountains

作　　者：王志康 祝乐 许晨阳 李艳 耿增超 王强 刘莉丽[4] 秦一郎 杜旭光 WANG Zhikang;ZHU Le;XU Chenyang;LI Yan;GENG Zengchao;WANG Qiang;LIU Lili;QIN Yilang;DU Xuguang(College of Natural Resources and Environment,Northwest Agriculture and Forestry University,Key Laboratory of Plant Nutrition and Agri-environment in Northwest China,Ministry of Agriculture,Yangling 712100,China;Cultivated land Quality and Agri-environment Protection Workstation,Department of Agriculture and Rural Affairs of Shaanxi Province,Xi′an 710000,China;Key Laboratory for Agricultural Environment,Ministry of Agriculture,Beijing 100081,China;College of Forestry,Northwest Agriculture and Forestry University,Yangling 712100,China;Agrotechnical Promotion Station in Mianxian Country,Hanzhong 724200,China;Qingdao Greensum Ecology Co.,LTD,Qingdao 266102,China;Agriculture and Animal Husbandry Ecological Resources Protection Center of Ulanqab,Ulanqab 012000,China)

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,杨陵712100 [2]陕西省耕地质量与农业环境保护工作站,西安710000 [3]农业部农业环境重点实验室,北京100081 [4]西北农林科技大学林学院,杨凌712100 [5]汉中市勉县农业技术推广站,汉中724200 [6]青岛冠中生态股份有限公司,青岛266102 [7]乌兰察布市农牧业生态资源保护中心,乌兰察布012000

出　　处：《生态学报》2022年第13期5493-5503,共11页Acta Ecologica Sinica

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

摘　　要：研究凋落物去除对秦岭天然林土壤团聚体稳定性及细根分布特征的影响机制,为森林生态治理提供理论依据。结果表明:(1)凋落物去除导致云杉林10—40 cm土层土壤中粒径大于0.25 mm水稳性团聚体含量(WR_(0.25))较对照显著降低(P<0.05);混交林10—40 cm土层的大于0.25 mm机械稳定性团聚体含量(DR_(0.25))显著降低(P<0.05);红桦林表层0—10 cm土壤团聚体的平均质量直径(MWD)显著降低(P<0.05);(2)凋落物去除导致三种天然林0—20 cm土层的细根生物量密度(FRBD)较对照显著降低44.18%—57.24%,细根体积(FRV)显著降低24.64%—60.41%;三种天然林中红桦林0—40 cm各土层的FRV最高;(3)凋落物去除导致云杉林0—40 cm土层的土壤容重较对照显著增加5.24%—13.04%,三种天然林0—40 cm土层的土壤有机碳含量显著降低7.92%—25.21%,全氮含量显著降低10.17%—18.10%;(4)相关分析表明,云杉林土壤的团聚体破坏率(PAD)和土壤不稳定团粒指数(E_(LT))与FRBD、细根根长密度(FRLD)和FRV均呈极显著负相关,混交林土壤的PAD与FRBD呈极显著负相关关系(r=-0.814),红桦林土壤团聚体MWD与FRBD、FRLD和细根比根长(FSRL)均呈显著负相关关系(r=-0.777、-0.771和-0.786)。综上,凋落物去除在总体上降低了天然林土壤团聚体的稳定性及有机碳和全氮含量,并且不利于林木细根的生长。The objective of this study is to investigate the effects of litter removal on the characteristics of soil aggregates stability and fine root distribution so as to provide theoretical bases for vegetation restoration and ecological protection in Qinling Mountains.Results indicated that(1)the litter removal significantly decreased the percentages of>0.25 mm water⁃stable aggregates(WR_(0.25))in 10—40 cm soil layer(P<0.05).The percentage of>0.25 mm mechanical⁃stable aggregates(DR_(0.25))in 10—40 cm soil layer of mixed forest was also decreased significantly(P<0.05).The mean weight diameter(MWD)of aggregates in 0—10 cm soil layer of Betula albosinensis forest was decreased(P<0.05)by litter removal.(2)By litter removal,the fine root biomass density(FRBD)in 0—20 cm soil layer of the three forests significantly decreased by 44.18%—57.24%;the fine root volume(FRV)significantly decreased by 24.64%to 60.41%.The FRV in 0—40 cm soil layer of Betula albosinensis forest was the highest among the three forests.(3)After 3⁃year litter removal,the soil bulk density in 0—40 cm soil layer of Picea asperata forest significantly decreased by 5.24%—13.04%.The soil organic carbon contents in 0—40 cm soil layer of the three forests significantly decreased by 7.92%—25.21%,and the contents of total nitrogen significantly decreased by 10.17%—18.10%.(4)The results of correlation analysis showed that percentage of aggregate destruction(PAD)and unstable soil aggregate index(E_(LT))of Picea asperata forest soil had significantly negative correlations(P<0.01)with FRBD,fine root length density(FRLD),and FRV.The PAD of mixed forest soil showed a significantly negative correlation(P<0.01)with FRBD(r=-0.814).The aggregate MWD of Betula albosinensis forest soil had significantly negative correlations(P<0.01)with FRBD,FRLD and fine specific root length(FSRL)(r=-0.777,-0.771 and-0.786).Overall,the litter removal decreased the stability of soil aggregates,the contents of soil organic carbon and total nitrogen in soils of natu

关 键 词：天然林 凋落物去除 团聚体稳定性 细根分布 

分 类 号：S718.5[农业科学—林学]