摘要
【目的】揭示国内外单树种纯林经营,特别是单树种针叶纯林经营和连作经营,所引起的土壤质量退化和林木生长量下降的状况及其作用机制,阐明发展有群落结构混交林是维护、恢复和提高森林土壤功能的机制及其经营技术途径。【方法】依据多年来研究我国主要造林树种人工林土壤质量退化的状况与机制,及其防治技术的实践,广泛查阅国内外有关资料,深入研究国内外单树种纯林经营、特别是针叶纯林经营、连作经营引起土壤质量下降及其防治措施的进展。通过对比的方法,即比较单树种纯林与相似立地条件、不同林分类型混交林土壤的理化性质及生物学活性变化的差异,揭示单树种纯林、特别是针叶纯林经营和连作经营引起土壤质量下降的机制,阐明混交林维护、恢复和提高土壤功能的机制及其技术途径。【结果】相似立地条件下,单树种纯林、特别是单树种针叶纯林经营和连作经营,与不同林分类型的混交林比较,其凋落物量下降,土壤有机质的量和质下降、有效磷含量下降、交换性阳离子含量下降、pH值下降、土壤生物化学活性下降、土壤肥力下降,病虫害严重,林木生长量下降。研究也阐明了发展我国主要造林树种混交林可选择的混交树种、混交比例和混交模式,指出了改造现有的单树种纯林、特别是长势差的单树种针叶人工林,使之成为不同林分类型有群落结构的混交林的经营技术途径。【结论】发展有群落结构混交林是维护、恢复和提高森林土壤功能,提高森林土壤生产力,实现可持续经营的关键技术。
【Objective】To reveal the mechanism of soil quality degradation and forest tree growth decline caused by mono culture of single species especially single conifer species,and consecutive cropping and to illustrate the mechanism and technical approach of the development of mixed forest with community structure in maintaining,restoring and improving the functions of forest soil.【Method】Based on many years of studies on conditions and mechanisms of soil quality degradation of major forest plantations in China and practices of degradation control,and on an extensive literature study,both home and abroad,paper in-depth explore advance of the soil quality degradation and prevention and treatment caused by domestic and foreign single tree pure forest management especially management of single species coniferous pure forest,continuous cropping.A comprehensive comparison of physical and chemical properties of soil and biological activities between the single conifer species forest and different stand types of the mixed forests under similar site conditions was conducted to reveal the mechanisms of soil degradation due to mono culture of single species especially single conifer species and consecutive cropping,and to illustrate the mechanisms of and technical approaches to maintaining,restoring and improving soil functions of mixed forest.【Result】Under similar site conditions,the monoculture of single species forest especially single conifer speciesforest and consecutive cropping in comparison with different stand types of the mixed forests showed decreases in the amount of litter,the quality and quantity of soil organic matter,the contents of available phosphorus,exchangeable cation,pH value,soil biochemical activities,soil fertility and tree growth,as well as the increase of severity of diseases and pests.Alternative species,proportions and models for mixed forests is clearly illustrated for the development of mixed forests with main afforestation tree species,technical approaches to improve existing single species forest especially the single conifer species plantations with poor growth into mixed forest with community structure is thoroughly elaborated.【Conclusion】The development of mixed forest with community structure is the key technology to maintain,restore and improve forest soil functions,to improve forest soil productivity and to achieve sustainable management of forest plantations.
作者
杨承栋
Yang Chengdong(Research Institute of Forestry,CAF,Beijing 100091)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2022年第8期26-40,共15页
Scientia Silvae Sinicae
关键词
针叶林
阔叶林
混交林
土壤质量
土壤生物化学活性
coniferous forest
broad-leaved forest
mixed forest
soil quality
soil biochemical activity
