机构地区:[1]北京林业大学国家林业和草原局森林经营工程技术研究中心
出 处:《生态学报》2020年第4期1195-1206,共12页Acta Ecologica Sinica
基 金:国家重点研发计划重点专项项目(2017YFC050400103);国家自然科学基金项目(31670643)
摘 要:长白山次生针阔混交林是东北地区典型的次生林类型之一,处于向地带性顶级植被阔叶红松林方向演替的重要阶段。全面分析长白山次生针阔混交林群落动态,能为东北地区森林保护、恢复和可持续经营提供理论支撑。基于长白山地区5.2 hm^2次生针阔混交林动态监测样地,以2005和2017年样地内所有胸径(DBH)≥5cm的木本植物为研究对象,分析了12年间群落的物种组成、物种多样性、胸径结构和密度结构等非空间结构,以及林木空间分布格局、树种混交和林木竞争等空间结构的变化。结果表明:群落个体数量由6614株降至5884株,2017年调查到木本植物13科25属42种,较2005年增加2属2种,群落物种组成和多样性变化较小。平均胸径由14.4 cm增加至15.5 cm;径级结构在两次调查中均呈倒"J"型,虽然群落保持稳定的更新态势,但是各径级的个体数量显著下降。胸径变异系数和基尼系数分别由0.77和0.37增至0.79和0.38,群落复杂程度提高。群落株数密度由1272株/hm^2降至1132株/hm^2,林分密度由33.12 m^2/hm^2增至34.74m^2/hm^2。群落空间结构在两次调查中没有变化,群落水平分布格局为随机分布(U=0.51),大小分化程度为中庸分布(U=0.50),混交度为强度混交(U=0.76),空间结构稳定。研究还比较了样地和20m×20m样方尺度上的群落结构变化趋势,发现大部分指标在两个尺度上变化一致。综上所述,本研究中的长白山次生针阔混交林的群落非空间结构呈现正向演替趋势,而空间结构保持相对稳定,群落整体在12年内并未发生本质性改变。在未来经营中,可适当伐除假色槭和色木槭等林下层树种,为红松、蒙古栎和紫椴等顶级树种的生长和更新提供空间。The secondary coniferous and broad-leaved mixed forest in Changbai Mountains is one of the typical secondary forest types in northeast China.It is in an important stage of succession to the climax vegetation,i.e.broad-leaved Korean pine forest.Through a comprehensive analysis of community dynamics in the secondary coniferous and broad-leaved mixed forest in Changbai Mountains,we can provide the scientific support for forest conservation,restoration and sustainable management.Based on a 5.2 hm^2 dynamic monitoring plot in Changbai Mountains in 2005 and 2017,all woody plants with DBH≥5 cm were investigated as study objects.The non-spatial structure dynamics including species composition,species diversity,DBH structure and density structure,and the spatial structure dynamics including the spatial distribution pattern,tree species mixed and trees competition were analyzed.The results showed that the total number of individuals in the community decreased from 6614 to 5884.Forty-two species of the plants belonging to 25 genera and 13 families were found in 2017,which increased by 2 genera and 2 species compared with those in 2005.These indicated that the variation of species composition and diversity was small.The average DBH increased from 14.4 cm to 15.5 cm.Although the community maintains an inverted"J"type of DBH structure and a positive regeneration,the number of individuals at each diameter level was significantly reduced.The coefficient of DBH variation and DBH Gini index increased from 0.77 and 0.37 to 0.79 and 0.38,respectively,indicating the complexity of the community increased.The stem density of community individuals decreased from 1272 to 1132 per hectare,and the stand density increased from 33.12 m^2/hm^2 to 34.74 m^2/hm^2.The spatial structure of the community did not change during the two censuses.The horizontal distribution pattern of the community was randomly distributed(U=0.51).The degree of size differentiation was moderate(U=0.50).The mingling degree was strong(U=0.76).Those indicated that the
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