滇中主要森林类型土壤团聚体稳定性及其变化机制  

Stability and Mechanisms of Soil Aggregates in Major Forest Types in Central Yunnan

作　　者：王平[1] 丁智强 李璐杉 李玉辉[1] Wang Ping;Ding Zhiqiang;Li Lushan;Li Yuhui(Department of Geography,Yunnan Normal University,Kunming 650500,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China;Fujian Sanming Forest Ecosystem National Observation and Research Station,Sanming,Fujian 365002,China;Zixi Middle School Chuxiong,Yunnan Province,Chuxiong,Yunnan 675099,China)

机构地区：[1]云南师范大学地理学部,昆明650500 [2]福建师范大学地理科学学院,福州350007 [3]福建三明森林生态系统国家野外科学观测研究站,福建三明365002 [4]云南省楚雄紫溪中学,云南楚雄675099

出　　处：《水土保持研究》2024年第5期232-242,共11页Research of Soil and Water Conservation

基　　金：云南省科技计划项目“云南山地河谷生物多样性保护及生态安全屏障建设”子课题“河谷绿色发展与生态安全屏障建设体系研究与示范”(202403AC100028)。

摘　　要：[目的]团聚体稳定性是评估退化生态系统植被恢复后土壤质量变化的重要指标,研究滇中地区主要森林类型土壤团聚体稳定性差异及其变化机制,为该地未来植被恢复、改造过程中的树种选择、森林资源管理提供科学支撑。[方法]选择云南松林(PY)、华山松林(PA)、银荆林(AD)、旱冬瓜林(ACF)、针阔混交林(TF)、次生常绿阔叶林(SF)6种主要森林类型作为研究对象,以坡旱地(DSL)作为对照,采集0—20 cm,20—40 cm和40—60 cm土样,利用干、湿筛分法分离测定>5 mm,5~2 mm,2~0.25 mm,<0.25 mm 4个粒级团聚体含量,计算水稳性大团聚体含量(WR_(>0.25))、平均重量直径(MWD)、几何平均直径(GMD)和结构破坏率(PAD)4个稳定性指标,对土壤团聚体稳定性进行研究。[结果](1) 6种森林类型在0—60 cm均以0.25~2 mm的小团聚体为主,而坡旱地随着土层深度的增加,粒级从0.25~2 mm向<0.25 mm转变;(2) 0—60 cm土层中坡旱地平均WR_(>0.25),MWD,GMD和PAD分别为55.40%,1.16 mm,0.52 mm,40.47%,6种森林类型分别为71.61%~78.20%,1.97~2.61 mm,0.93~1.27 mm,12.59%~20.47%,团聚体稳定性总体表现为坡旱地最差,次生常绿阔叶林、针阔混交林最好,其次是云南松林、旱冬瓜林,银荆林和华山松林较差;(3)团聚体稳定性在宏观尺度上受森林类型、土层深度及其交互作用的显著影响(p<0.001),而在微观尺度上主要受土壤容重、非毛管孔隙度、全钾、有机质、砂粒和黏粒含量的显著影响(p<0.05),土壤理化性质、养分、质地解释了团聚体稳定性的90.5%,其中以理化性质、养分及其交互作用的贡献最大,解释率为61.3%,土壤质地往往与其他因子共同影响团聚体稳定性,其独立解释率仅为5.1%。[结论]滇中地区退耕还林可显著提高土壤团聚体稳定性,未来的生态恢复应该以营造云南松林和旱冬瓜林为主,同时避免高强度的人类活动,改善土壤理化性质和增加土壤养分积累,促进人工[Objective] Aggregated stability is an important indicator for assessing changes in soil quality after vegetation restoration in degraded ecosystem.The aims of this study are to investigate the difference of soil aggregate stability and its change mechanism of main forest types in central Yunnan,and to provide scientific support for tree species selection and forest resource scientific management in the process of vegetation restoration and transformation in the future.[Methods] Six primary forest types,including Pinus yunnanensis forest(PY),Pinus armandii forest(PA),Acacia dealbata forest(AD) and Alnus cremastogyne forest(ACF),Theropencedrymion forest(TF),and Secondary evergreen broad-leaved forest(SF),were selected for the study.Dry slope land(DSL) was used as a control.Soil samples were collected from depths of 0—20 cm,20—40 cm,and 40—60 cm.Dry sieving and wet sieving methods were employed to classify aggregates into four size classes:>5 mm,5~2 mm,2~0.25 mm and<0.25 mm.Four stability indices,including WR_(>0.25),mean weight diameter(MWD),geometric mean diameter(GMD) and structural failure rate(PAD),were calculated to investigate soil aggregate stability.[Results](1) Among the six forest types,aggregates with a particle size range of 0.25~2 mm predominated in the 0—60 cm soil layers,while DSL shifted from 0.25~2 mm to<0.25 mm with increasing soil depth.(2) In the 0—60 cm soil layer,WR_(>0.25),MWD,GMD,and PAD values in DSL were 55.40%,1.16 mm,0.52 mm,and 40.47%,respectively.The six forest types exhibited aggregate stability ranging from 71.61% to 78.20% for WR_(>0.25),1.97 mm to 2.61 mm for MWD,0.93 mm to 1.27 mm for GMD,and 12.59% to 20.47% for PAD.Overall,DSL exhibited the poorest aggregate stability,followed by SF and TF,while PY,ACF,AD,and PA showed relatively lower stability.(3) At the macro scale,soil aggregate stability in the study area was significantly influenced by forest type,soil depth,and their interaction(p<0.001).At the micro scale,it was mainly affected by soil bulk density,non-capilla

关 键 词：土壤团聚体 稳定性 影响因素 森林类型 滇中地区 

分 类 号：S157.5[农业科学—土壤学]