摘要
东灵山暖温带落叶阔叶次生林,是保存较完整的落叶阔叶次生林,其物种组成、群落结构是次生林演替过程的重要体现,也是下一步演替发生的基础。为了更好地研究其演替动态、生物多样性维持机制,以东灵山20hm^2样地为固定监测平台,分析了暖温带落叶阔叶次生林的活立木、枯立木物种组成、径级结构、空间格局。结果表明:(1)样地中DBH≥1 cm的活立木共有103702株,植株密度为5185.1株/hm^2;枯立木共有4543株,植株密度为204.9/hm^2二者均包括了分枝和萌枝的个体数。样地内DBH≥1 cm的活立木共有58种,分属于33属18科,DBH≥1 cm的枯立木共有33种,分属于23属15科。(2)活立木与枯立木整体分布随径级增大,均表现出先增大后减小的趋势,小径级个体多度在分布中优势显著。(3)活立木空间分布随径级增大,聚集强度减小,10 cm≤DBH<20 cm、DBH≥40 cm此趋势明显,而20 cm≤DBH<40 cm在0—50 m的尺度范围内,规则、随机、聚集分布均出现。枯立木的空间格局,DBH<5 cm,DBH≥40 cm,尺度接近30 m时,随机分布;5 cm≤DBH<40 cm,0—50m尺度范围内,聚集分布。空间分布格局显示了径级大小在空间分布上互补,不同径级的个体占据了样地内不同的生态位。(4)不同径级活立木与枯立木关联性分析表明,小径级小尺度,关联显著,大径级大尺度空间关联性逐渐减弱。枯立木的产生,是活立木受密度制约调控、演替地位及演替阶段、生境异质性等因素调控的结果,影响机制有待进一步研究。
The warm temperate deciduous broad-leaved secondary forest in Dongling Mountain is relatively well-preserved. Species compositions and community structures are important in the process of secondary forest succession and are also the basis for the next succession. To further study the secondary forest dynamics of biodiversity succession and conservation mechanisms, a relatively large 20 hm^2 experimental forest fixed monitoring sample plot in Dongling Mountain was chosen, and the species composition, diameter class structures, and spatial patterns of live standing trees and snags of the warm temperate deciduous broad-leaved secondary forest were analyzed. The results showed that (1) there were 103702 live standing trees with DBH ≥ 1 cm, and a density of 5185.1/hm^2 in the plot; there were 4543 snags with a density of 204.9/hm^2, both of which included the quantities of branches and sprouted branches. There were 58 species of live standing trees with DBH ≥ 1 cm in the plot, belonging to 33 genera and 18 families; and 33 species of snags with DBH ≥ 1 cm belonging to 23 genera and 15 families; (2) in terms of overall distribution, the diameters of live standing trees and snags fluctuated, showing a trend of first increasing and then decreasing, and the individual abundance of smaller sized trees had significant advantages in distribution; (3) for live standing trees, as the diameter increased, the aggregation intensity decreased, with 10 cm ≤ DBH 〈 20 cm and DBH ≥ 40 cm, whereas regular, random and aggregate distributions occurred with 20 cm ≤ DBH 〈40 cm in a scale of 0-50 m. For snags, when DBH 〈 5 cm and the scale was close to 30 m, a random distribution appeared; moreover, when DBH ≥ 40 cm and the scale was close to 30 m, there was a continuous random distribution, and a clumped distribution occurred when 5 cm ≤ DBH 〈 40 cm. The spatial distribution patterns showed that sizes of diameters were complementary in spatial structures, and individuals with different diameters occupied different niches in the sample plot; (4) the correlation analysis between different sizes of live standing trees and snags showed that the smaller the diameters and scales, the more obvious relevance, whereas the spatial correlation of large sizes and scales were gradually weakened. Snag production was affected by the density dependence, status and stages of succession of live trees, and habitat heterogeneity; however, the mechanisms involved still need to be studied further.
作者
马芳
王顺忠
冯金朝
桑卫国
MA Fang;WANG Shunzhong;FENG Jinchao;SANG Weiguo(College of Life and Environmental Sciences,Minzu University of China,Beijing 100081,China;State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China)
出处
《生态学报》
CAS
CSCD
北大核心
2018年第16期5717-5725,共9页
Acta Ecologica Sinica
基金
国家自然科学基金项目(31570630)
关键词
点格局分析
密度制约
聚集
生态位
树木死亡
point pattern analysis
density dependence
aggregation
niche
tree death