摘要
【目的】通过明晰人工纯林转变为混交林对土壤团聚体稳定性及有机碳含量的影响,为人工林的可持续发展提供数据支撑。【方法】以巨桉纯林皆伐后营建的红叶碧桃+西府海棠混交林(林分类型Ⅰ)、杉木+桢楠+红叶碧桃混交林(林分类型Ⅱ)、香樟+水杉混交林(林分类型Ⅲ)和巨桉纯林(CK)为对象,测定了林分营建4年后0~20 cm和20~40 cm土层的土壤理化性质、团聚体粒径分布、团聚体稳定性指标、团聚体有机碳含量及对其全土有机碳(SOC)的贡献。【结果】①与对照相比,林分类型Ⅲ显著促进了各土层小粒径团聚体向>2 mm大团聚体的转化,显著提高了各土层土壤团聚体平均重量直径(MWD)、几何平均直径(GMD)和水稳性大团聚体比重(R0.25),显著降低了分形维数(D)和团聚体破坏率(PAD);>2 mm大团聚体质量占比是驱动土壤团聚体稳定性变化的关键环境因子。②各林分类型各土层土壤团聚体有机碳含量介于7.54~27.06 g/kg间,>2 mm大团聚体是携带SOC的主要组分,林分类型Ⅲ显著提高了各土层>2 mm大团聚体有机碳含量及其对SOC的贡献率;SOC是驱动土壤团聚体有机碳变化的关键环境因子。③林分类型Ⅰ和Ⅱ对土壤团聚体粒径分布、团聚体稳定性、团聚体有机碳含量及其对SOC的贡献总体上影响不显著。【结论】在混交林营建初期,香樟+水杉混交林在提高土壤结构稳定性和固碳能力方面的作用更加明显,因此可选择香樟+水杉混交林来改造研究区的巨桉纯林。
【Objective】This study provides empirical evidence for the sustainable development of artifi-cial forests by elucidating the impact of converting monoculture plantations into mixed-species forests on soil aggregate stability and organic carbon content.【Method】Three mixed forest types were established following clear-cutting of pure Eucalyptus grandis plantations,namely Amygdalus persica'Atropurpurea'+Malus×micromalus(stand type I),Cunninghamia lanceolata+Phoebe zhennan+Amygdalus persica'Atropurpurea'(stand typeⅡ),Camphora officinarum+Metasequoia glyptostroboides(stand type III),alongside a control group of pure E.grandis forest(CK).Four years after stand establishment,we deter mined soil physical and chemical properties,aggregate size distribution,aggregate stability indices,ag-gregate organic carbon content,and its contribution to total soil organic carbon(SOC)in the 0-20 cm and 20-40 cm soil layers of each stand type.【Result】①Compared to the CK treatment,stand typeⅢsignificantly promoted the conversion of small aggregates into>2 mm macro-aggregates across both soil layers,markedly increasing mean weight diameter(MWD),geometric mean diameter(GMD),and the macroaggregate proportion(R0.25)in each soil layer,while significantly reducing fractal dimension(D)and the percentage of aggregate disruption(PAD).The mass ratio of>2 mm aggregates was identified as the key environmental factor driving changes in soil aggregate stability.②The organic carbon content of soil aggregates in each stand type and each soil layer ranged from 7.54 to 27.06 g/kg,with aggregates larger than 2 mm serving as the main SOC carriers.Stand typeⅢsignificantly enahnced the organic car-bon content of>2 mm aggregates and their contribution to SOC in both soil layers,with SOC identified as the key environmental driver of aggregate organic carbon changes.③Stand typesⅠandⅡhad no sig-nificant effects on aggregate size distribution,aggregate stability,aggregate organic carbon content and its contribution to SOC.【Conclusion】The C.officinarum+M.glyptostroboides mixed forest markedly improves soil structural stability and carbon sequestration during the early stage of mixed forest establish-ment.Therefore,this mix forest type is recommended for transforming E.grandis monocultures in the study area.
作者
蒋明朱
樊戢
李哲
徐晶楠
肖欢
胡峻嶍
周世兴
黄从德
JIANG Mingzhu;FAN Ji;LI Zhe;XU Jingnan;XIAO Huan;HU Junxi;ZHOU Shixing;HUANG Congde(Sichuan Mt.Emei Forest Ecosystem National Observation and Research Station/Forest Ecology and Conservation in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province/College of Forestry,Sichuan Agricultural University,Chengdu 611130,China;Sichuan Provincial Institute of Forestry and Grassland Inventory and Planning,Chengdu 610081,China)
出处
《四川农业大学学报》
北大核心
2025年第4期933-942,958,共11页
Journal of Sichuan Agricultural University
基金
世界银行贷款长江上游森林生态系统恢复项目(510201202038467)。
关键词
巨桉人工林
混交林
土壤团聚体稳定性
土壤团聚体有机碳
Eucalyptus grandis plantation
mixed forest
soil aggregate stability
soil aggregate organic carbon
