[目的] 分析湖北七姊妹山6 hm2亚热带常绿落叶阔叶混交次生林动态监测样地中优势物种的空间分布格局,阐明群落恢复过程中物种共存机制,为森林生态系统恢复和多样性保护提供理论依据.[方法] 通过空间点格局分析法,将川陕鹅耳枥和多脉青冈按胸径(DBH)划分4个径级: 幼树(1 cm ≤ DBH ＜ 2. 5 cm)、小树(2. 5 cm≤DBH ＜ 5 cm)、中树(5 cm≤DBH ＜10 cm)和成年树(DBH≥10 cm),分析2个优势种不同径级的个体数量、空间分布、种内及种间相关性.[结果] 在4个径级段上,川陕鹅耳枥个体数量基本相同,多脉青冈为倒" J"型分布,但2个物种各径级内的个体均具有相似的生境偏好;川陕鹅耳枥与多脉青冈各径级个体主要表现为聚集分布,随着径级增加聚集程度逐渐减弱;随空间尺度增大,川陕鹅耳枥中树对幼树种内相关性表现出由显著正相关(P＜0. 05)向无显著相关性的递减趋势,成年树对幼树表现出由无明显相关性向显著负相关性(P＜0. 05)递减的趋势,小树对幼树、中树对小树、成年树对中树、成年树对小树均表现出显著( P＜0. 05)正相关; 多脉青冈各径级个体间均表现为显著正相关性(P＜0. 05),且随着空间尺度的增大而减弱; 不同径级的川陕鹅耳枥对多脉青冈各径级个体均表现为显著正相关性(P＜0. 05),并随着空间尺度的增大而减弱;随空间尺度增大,较大径级(中树和成年树)的多脉青冈个体对川陕鹅耳枥幼树和小树表现出由无明显相关性向显著负相关( P＜0. 05)的变化趋势,并且径级差距越大,负相关性越强.[结论] 湖北七姊妹山亚热带常绿落叶阔叶混交林次生林中优势种(川陕鹅耳枥与多脉青冈)具有相似的生境偏好,演替后期种(多脉青冈)对前期种(川陕鹅耳枥)具有显著的抑制作用,而前期种促进后期种的定居与生长.随着群落恢复,次生林样地将逐步成为后期种占优势的森林群落.本研究结果通过展现物种间关联性的变化也表明,物种关联性的变化过程驱动森林群落构建过程.

This article studied the community structure,species composition, species richness and species diversity of the woody plants in Xingdoushan nature reserve.The results show that ① The woody plant species are rich,and the dominant species are clear in Xingdoushan;② The pantropic and north temperate distribution types are the most abundant in terms of the plant community composition in Xingdoushan;③ Two community types have high species richness in Xingdoushan,Shannon-Weiner index is positively correlated with Simpson index in each layer in community Ⅰ,and tree layer has the biggest diversity index and dominance index.In community Ⅱ,Pielou evenness index is positively correlated with Shannon-Wiener diversity index,but negatively correlated with Simpson dominance index in all layers,and the tree layer has the biggest species richness and dominance,low evenness and diversity index.

为定量分析不同海拔梯度上马尾松(Pinus massoniana)天然群落的结构特征,采用物种丰富度R、Simpson指数和Shannon-Wiener指数对马尾松天然群落生物多样性进行了测定,并对群落垂直结构、主要优势种重要值、群落生活型等进行了探讨.结果表明:①马尾松天然群落有植物11746株,分属51科97属116种,物种随海拔梯度上升而增加.其中,中海拔梯度(Ⅱ、Ⅲ)的物种多样性最丰富,山杜英(Elaeocarpus sylvestris)在低海拔梯度和高海拔梯度中均有分布;②随海拔梯度上升,4个海拔梯度乔木层主要优势种的种类依次为5种、13种、6种、8种.其中每个海拔梯度中均有马尾松分布,其重要值随海拔梯度上升呈现"下降-上升-下降"趋势;③随海拔梯度上升,群落物种丰富度呈"上升-下降-上升"趋势;群落物种多样性随海拔上升呈线性增长;④群落树高随海拔梯度上升而增高,其中群落平均树高多在9m以上,主要分布在5~10m区间.⑤群落中落叶型植物多于常绿型.随海拔梯度上升,落叶乔木呈"下降-上升"趋势,常绿乔木呈"上升-下降-上升"趋势;常绿灌木呈上升趋势,落叶灌木呈"下降-上升"趋势.海拔梯度的变化使马尾松天然群落的结构特征存在一定差异,这为马尾松天然林的经营管理、生物多样性保护等方面提供了指导意义,也为揭示此类森林群落结构特征变化规律提供了重要的参考价值.

在双向指示种分析(TWINSPAN)的基础上,采用Levins和Pianka生态位测度公式以及总体相关性VR检验、Pearson相关系数和Spearman秩相关系数,定量分析木林子川陕鹅耳枥+青冈-水马桑(Carpinus fargesiana+Cyclobalanopsis glauca-Weigela japonica)群落10个优势种群的生态位和种间关联特征.结果表明:①川陕鹅耳枥(Carpinus fargesiana)、青冈(Cyclobalanopsis glauca)、四照花(Dendrobenthamia japonica)的重要值和生态位宽度较大,资源利用谱宽,属泛化种;小叶青冈(Cyclobalanopsis myrsinifolia)与其他优势种生态位重叠的均值最小,资源利用特化程度高,属特化种.②优势种群种对的生态位重叠平均值为0.59,资源利用方式分化较小.③优势种的种对正负关联比为0.73∶1且均为不显著关联,群落物种间总体显著正关联.④种间关联系数Pearson、Spearman的值均与Pianka生态位重叠值呈极显著正相关.

In this paper, ethnology investigation method and community ecology conventional survey method were used to study the niche breadth and niche overlap of tree layer main species in the original Metasequoia glyptostroboides mother trees communities.Metasequoia glyptostroboides which was most adaptable to the environment in the community and occupied the dominant position in the community had the biggest important value and niche breadth value.The most niche overlap value of Metasequoia glyptostroboides and Cryptomeria fortune was 0.819.The niche overlap value of Metasequoia glyptostroboides and Cunninghamia lanceolata was 0.807.There was a big competition among these spieces.The niche overlap value between Cryptomeria fortunei and Cunninghamia lanceolata was 0.729, which were on the same level in the community vertical structure and had a fierce competition in sunlight and space.In order to better adapt to the internal environment in the community, there was differentiation among the location of each species in the community.

用双向指示种分析法(TWINSPAN)将星斗山自然保护区常绿落叶阔叶混交林划分为两个群落类型,即亮叶水青冈+多脉青冈-翅柃(Fagus lucida+Cyclobalanopsis multinervis-Eurya alata)群落(群落Ⅰ)和川陕鹅耳枥+交让木+包槲柯-翅柃(Carpinus fargesiana+Daphniphyllum macropodum+Lithocarpus cleistocarpus-Eurya alata)群落(群落Ⅱ),以重要值(Ⅳ)为资源位,分析群落乔木层优势种的生态位宽度和生态位重叠.结果显示:群落Ⅰ中交让木(Daphniphyllum macropodum)与川陕鹅耳枥(Carpinus fargesiana)之间的生态位重叠值较大,为了更好的适应群落内部环境和利用种间资源,它们在垂直结构上发生了分化;齿缘吊钟花(Enkianthus serrulatus)与长蕊杜鹃(Rhododendron stamineum)之间的生态位重叠值为0.898,由于在乔木层中占据同一个层次,为了争夺群落间共有的营养和空间资源发生了激烈的竞争;群落Ⅱ中交让木与亮叶桦(Betula luminifera)之间的生态位重叠值最大,它们在垂直结构上发生了分化;交让木与多脉青冈(Cyclobalanopsis multinervis)之间的生态位重叠较大,它们在乔木层中占据同一个层次,竞争较激烈.

The Dendrobenthamia japonica (DC.) Fang population, the dominant species of the forest dy-namics plot in Mulinzi National Nature Reserve of Hubei Province,was studied in this article. Its point pattern and pearson correlation with some environmental factors around it was researched and calculated. The results are as follows:This population obeys an aggregated distribution in meso-and micro-scale and its aggregation intensity fluctuates to a certain degree,but its spatial pattern changes from a random distri-bution to an regular distribution.The positive correlation property between the individuals declines with the age of the population, which leads to the declining of the aggregation intensity.What′s more,the bigger the age gap is,the more outstanding the negative correlation is. The spatial correlation between the Den-drobenthamia japonica (DC.) Fang population with the Carpinus fargesiana H. Winkl. population and the Sorbus folgneri ( Schneid.) Rehd. Population is positive and outsanding, while with the Cyclobalanopsis myrsinaefolia (Blume) Oerst. population is negative and outsanding.Finally,we also find that the distribu-tion of the Dendrobenthamia japonica (DC.) Fang population is influenced by some environmental factors including the elevation,the convexity,the gradient,the pH of soil,but not by the slope aspect.

Mixed evergreen and deciduous broad-leaved forest is a typical natural vegetation type and natural forest type in China. In order to study the dominant and associated population structure and its dy-namicst and reveal the mechanism of the formation and maintenance of biodiversity,we rely on the con-struction of National Forest Ecosystem Research Station of Hubei Enshi, to investigate the plant communi-ty of mixed evergreen and deciduous broad-leaved forest in different stages of natural recovery in Mulinzi Nature Reserve, and we analyzed the community characteristics of dominant and associated populations from the aspects of species composition, the areal-types, the diameter class structure and the vertical structure. The results show that: Among the dominant and associatedpopulations in different recovery communities, the species number of woody plants at breast height ( DBH)≥1 cm is 148,176,149 and the plant number is 6 970,4 533,4 048.They belong to 23 genera of 14 families,26 genera of 19 families and 25 genera of 16 families.Overall, the species richness of the dominant species showed the″unimodal type″with the vertical layer drops in the 3 stages of natural recovery,the individual abundance increases with the decrease of the vertical layer.The average tree height is 5.94,5.21 and 4.61 m respectively. The spe-cies richness of different recovery communities decreases with the increase of the diameter class in differ-ent recovery communities,individual multi degree is inverted ″J″ type distribution. The number of small diameter class is large,the average tree DBH is 4.18,4.35 and 4.48 cm respectively. In short, the species composition of the forest communities is rich in the mixed evergreen and deciduous broad-leaved forest in different stages of natural recovery in Mulinzi Nature Reserve. Most of the population naturally updates well and the whole community is in a positive succession.

小叶青冈是我国亚热带常绿落叶阔叶混交林的主要优势树种之一,也是良好的用材树种和园林树种.本文采用胸径代替年龄和点格局分析(Ripley's K-Function)法对湖北木林子15 hm2大样地内小叶青冈种群的年龄结构和空间点格局进行了分析.结果显示:大样地内小叶青冈种群属增长型种群,其种群的存活曲线特征属DeeveyⅡ型,种群在幼树阶段死亡率较高,之后趋于稳定;种群整体及幼树、小树、中树和大树四个年龄段的个体在空间分布格局上随研究尺度的变化均呈集群分布,而老树年龄段的个体,其空间分布格局随研究尺度的增加由均匀分布向集群分布递变;在呈集群分布的尺度范围内,都存在随研究尺度的增加,聚集强度先减小后增大的规律.