广西马尾松林分类、分布和演替的研究

马尾松林是常绿阔叶林演替系列中的一个演替阶段,在广西各个地理区域都有广泛的分布,主要见于海拔1300m以下红、黄壤丘陵山地。本文通过群落分类研究划分出3个群丛纲76个群丛。分析这些群丛的外貌、结构和种类成分的变化,可确定其演替趋向和所处的演替阶段,为其合理经营管理提供科学依据。     

广西拟赫杨林分类和演替的研究

拟赫杨林是亚热带落叶阔叶林的一个群落类型,属于常绿阔叶林演替系列的一个演替阶段,主要见于东部中亚热带地区海拔１３００ｍ以下的红壤和黄壤山地山坡中下部环境比较湿润的地方,本研究划分出３个群丛纲和１３个群丛。它向常绿阔叶林恢复的演替趋向,从１３个群丛之间的群落外貌,结构和种类组成变化的分析可以得到充分的证明。     

广西大穗鹅耳枥林的分类和演替趋向

大穗鹅耳枥林是广西东北部黄壤山地常绿阔叶林遭受砍伐后,在保护较好的情况下迅速发展起来的一个演替阶段。本文通过群落分类的研究,从不同群丛的外貌、结构和种类组成的变化,论证其向常绿阔叶林恢复过程的演替趋向。     

广西拟赤杨林分类和演替的研究

拟赤杨林是亚热带落叶阔叶林的一个群落类型 ,属于常绿阔叶林演替系列的一个演替阶段 ,主要见于东部中亚热带地区海拔 1 30 0m以下的红壤和黄壤山地山坡中下部环境比较湿润的地方 ,本文研究划分出 3个群丛纲和 1 3个群丛。它向常绿阔叶林恢复的演替趋向 ,从 1 3个群丛之间的群落外貌 ,结构和种类组成变化的分析可以得到充分的证明。     

广西拟赤杨林分类和演替的研究

拟赤杨林是亚热带落叶阔叶林的一个群落类型,属于常绿阔叶林演替系列的一个演替阶段,主要见于东部中亚热带地区海拔1300m以下的红壤和黄壤山地山坡中下部环境比较湿润的地方,本文研究划分出3个群丛纲和13个群丛。它向常绿阔叶林恢复的演替趋向,从13个群丛之间的群落外貌,结构和种类组成变化的分析可以得到充分的证明。     

广西拟赤杨林分类和演替的研究

拟赤杨林是亚热带落叶阔叶林的一个群落类型,属于常绿阔叶林演替系列的一个演替阶段,主要邮于东部中亚热带地区海拔１３００ｍ以下的红壤和黄壤山地山坡中下部环境比较湿润的地方,本研究划分出３个群丛纲和１３个群丛。它向常绿阔叶林恢复的演替趋向,从１３个嫩丛之间的群落外貌,结构和种类组成变化的分析可以得到充分的证明。     

广西木荷林的分类和演替

木荷（ＳｃｈｉｍａｓｕｐｅｒｂａＧａｒｄｎ．ｅｔＣｈａｍｐ．）林是原来的常绿阔叶林遭受破坏以后,在保护较好的情况下,从演替系列群落顺向演替恢复为常绿阔叶林的一个早期类型。本文对广西木荷林进行分类,划分和论述７个群丛的种类组成特点和演替方向,可供进一步研究和规划退化生态系统的恢复和重建参考     

广西亚热带落叶阔叶林的分类系统及其管理

广西亚热带落叶阔叶林是亚热带地区几类顶极群落遭受破坏后恢复过程的一个演替阶段,类型多种多样。本文研究制定了它的分类系统,包括２个亚群系纲、１０个群系组、２７个群系和７７个群丛,扼要地阐述了它们的地理分布和生境特点,为其科学的管理提供基本依据。     

广西光皮桦林的分类和演替

光皮桦林是常绿阔叶林或山地常绿落叶阔叶混交林遭受砍伐后,在保护较好的情况下自然恢复起来的一种演替系列群落,属亚热带落叶阔叶林的一种类型。本文通过群落分类研究,划分出３个群丛纲和１１个群丛。从这些群丛的外貌、结构和种类成分的变化,可确定其演替的趋向和所处阶段,是合理经营管理它的科学依据。     

东太湖水生植物群落结构的演变及其沼泽化

2002年东太湖水生植被调查结果表明,沉水植被和浮叶植被是该湖水生植被的主要生态类型,分布面积分别占全湖总面积73.6%和18.3%。东太湖水生植被主要有9个群丛,其中沉水植被主要的5个群丛是伊乐藻(外来种)群丛、金鱼藻群丛、伊乐藻 微齿眼子菜群丛、菜-伊乐藻 微齿眼子菜群丛、苦草 竹叶眼子菜 黑藻群丛,其分布面积分别占东太湖植被总面积的30.7%、17.2%、16.7%、15.8%、9.3%。随着对东太湖的不断改造和资源的不断利用,20世纪60年代东太湖人工种植沼泽植被菰群丛,20世纪80年代初环湖水陆交错带被围垦而芦苇群丛消失,微齿眼子菜替代竹叶眼子菜而占据东太湖40%的水面。近10a来,东太湖网围养蟹迅速发展,占全湖总植被面积25.6%的沼泽植物——菰群丛及其占40%的微齿眼子菜群丛被清除,外来种伊乐藻和无根植物金鱼藻分布面积达90%的湖区。东太湖水生植被由20世纪50年代的原生演替到现在的次生演替,群落演变激烈,同时东太湖沼泽化进程加剧。     

深圳湾福田红树林群落演替

对深圳湾福田凤塘河红树林演替过程中的群落结构、物种组成、多样性变化及演替趋势的研究结果表明:(1)演替各阶段群落均由秋茄(Kandelia candel)、木榄(Bruguiera gymnorrhiza)、桐花树(Aegiceras corniculatum)、白骨壤(Avicennia marina)及老鼠簕(Acanthus ilicifolius)5个种类组成。(2)演替早期(4 a)群落高度增长较快,之后继续保持较快增长,至17 a时趋于稳定,之后增长速度缓慢。(3)4 a和17 a的群落立木级均分布在Ⅱ级—Ⅳ级,56 a和73 a的群落立木均达到最高级Ⅴ级,该两群落立木在Ⅱ级—Ⅴ级均有分布。(4)随着演替的进展,除了73 a群落盖度较56 a群落稍有下降外,其它演替群落盖度逐渐增加;群落胸高断面积表现出与盖度一致的变化趋势;群落个体密度则逐渐下降;群落物种多样性和均匀度不断提高,群落优势度则逐渐下降;群落相似性系数的变化表明在演替过程中群落物种组成结构没有发生明显变化。(5)群落变化及演替为:秋茄+桐花树群落→秋茄群落→白骨壤+秋茄群落→白骨壤群落。     

Forest Structure and Biomass of a Tropical Seasonal Rain Forest in Xishuangbanna,Southwest China1

Xishuangbanna is a region located at the northern edge of tropical Asia. Biomass estimates of its tropical rain forest have not been published in English literature. We estimated forest biomass and its allocation patterns in five 0.185–1.0 ha plots in tropical seasonal rain forests of Xishuangbanna. Forest biomass ranged from 362.1 to 692.6 Mg/ha. Biomass of trees with diameter at 1.3 m breast height (DBH) ≥ 5 cm accounted for 98.2 percent of the rain forest biomass, followed by shrubs (0.9%), woody lianas (0.8%), and herbs (0.2%). Biomass allocation to different tree components was 68.4–70.0 percent to stems, 19.8–21.8 percent to roots, 7.4–10.6 percent to branches, and 0.7–1.3 percent to leaves. Biomass allocation to the tree sublayers was 55.3–62.2 percent to the A layer (upper layer), 30.6–37.1 percent to the B layer (middle), and 2.7–7.6 percent to the C layer (lower). Biomass of Pometia tomentosa, a dominant species, accounted for 19.7–21.1 percent of the total tree biomass. The average density of large trees (DBH ≥100 cm) was 9.4 stems/ha on two small plots and 3.5 stems/ha on two large plots, illustrating the potential to overestimate biomass on a landscape scale if only small plots are sampled. Biomass estimations are similar to typical tropical rain forests in Southeast Asia and the Neotropics.     

Ecosystem recovery in terra firme forests after cutting and burning: a comparison on species richness, floristic composition and forest structure in the Jaú National Park, Amazonia

Six hectares, three in a primary forest and three in a 40 year old secondary forest were inventoried for all trees with Diameter at Breast Height (DNH) of 10 cm or greater in a terra firme forest 200 km north-east of Manaus, central Amazonia in order to compare the difference between structure, species richness and floristic composition. Both species richness and tree density were significantly higher in the upland forest than in the secondary forest. The forest structure pattern analysed (DBH, basal area and estimated dry biomass) did not differ significantly between the two forest types. Similarity indices at species level were only 14%. In the 3 ha of primary forest the number of species varied from 137 to 159, the number of individuals from 639 to 713, total basal area from 32.8 to 40.2 m² and estimate total of above-ground dry biomass (AGBM) from 405 to 560 tons per ha. In the 3 ha of secondary forest, the number of species varied from 86 to 90, the number of individuals from 611 to 653, total basal area from 28.8 to 39.9 m² and estimated total AGBM from 340 to 586 tons per ha. Family Importance Value (FIV) is the sum of relative density, dominance and richness of a family. The most important families in relation to FIV were Burseraceae, Chrysobalanaceae, Lecythidaceae, Myristicaceae, Bombacaceae, Fabaceae and Mimosaceae in the 3 ha of primary forest, while Burseraceae, Lecythidaceae, Sapotaceae, Arecaceae and Cecropiaceae were the most important families in the 3 ha of secondary forest. Importance Value Index (IVI) is the sum of relative density, dominance and frequency of a species. Alexa grandiflora (Caesalpiniaceae), Sckronema micranthum (Bombacaceae) and Pourouma guianensis (Cecropiaceae) were the most important species in relation IVI, in the primary forest, while Eschweilera grandiflora (Lecythidaceae), Protium apiculatum (Burseraceae) and Bertholletia excelsa (Lecythidaceae) were the most important species in the secondary forest. We conclude that species richness was significandy different between the two forests, but that forest structure patterns analysed in this study (DBH, basal area and dry biomass) were similar. This demonstrates that 40 years was sufficient time for the secondary forest to recover the original structure of the primary forest, but not the original species richness. The low species similarity between the two forests indicates that the floristic composition was quite distinct and that the mixture of primary forest and disturbed forest has led to an increase in total species diversity.     

Floristic composition,structure and regeneration status of Masha forest,south‐west Ethiopia

The natural forest of Masha was studied to determine the species composition and population structure of woody species in the area. A total of 130 plant species belonging 61 families were recorded, in which family Acanthaceae was represented by 11 species followed by Rubiaceae (10) and Asteraceae (9). The composition and population structure of woody species, with diameter at breast height (DBH) >2.5 cm and height >2 m, and their regeneration were assessed in 65 sample plots of 400 m² each. The density for trees and shrubs with DBH >2.5 cm was 1681 ind.ha^?1, and the basal area of the study area was 142.6 m² ha^?1. Four community types were recognized. This forest is of international and national conservation importance given its high biodiversity. Managing the remaining forest would be an appropriate option for sustainable management of biodiversity.     

川西亚高山森林不同恢复途径物种组成和群落结构动态变化

川西亚高山森林作为西南林区主体,是长江上游的生态屏障,该区域植被恢复方式主要为人工恢复和自然恢复,比较不同恢复方式下森林的物种组成和群落结构动态变化,对于川西亚高山森林恢复与重建有重要的意义,可以为制定合理的森林管理策略提供科学依据。基于茂县山地生态系统定位研究站不同恢复模式形成的的华山松人工林、油松人工林和自然恢复的次生林野外调查数据,分析了2005-2020年乔、灌、草三个层次的群落结构特征和多样性。结果表明:(1)不同恢复途径下,乔木层物种数都呈现增加趋势,华山松人工林、油松人工林、自然恢复的次生林乔木层物种数分别增加了11种、7种、8种;(2)华山松人工林中华山松重要值从48.06%降低到31.1%,乡土阔叶树种四川蜡瓣花进入乔木层,2020年重要值增大至21.62%,油松人工林中油松重要值逐渐降低,从43.59%降至29.76%;自然恢复的次生林中,乡土树种锐齿槲栎逐渐成为第一优势种,2020年重要值增至19.9%。(3) 华山松人工林、油松人工林和自然恢复的次生林中,温带区系成分分别占总属数的71.43%,80.77%和84%,温带区系特征明显。(4)华山松人工林和油松人工林乔木层径级结构均为偏正态分布;而自然恢复的次生林径级分布呈倒"J"形,以小径级个体为主。(5)不同林型的乔木层高度在15年间呈现增加的趋势,具体表现为油松人工林>华山松人工林>自然恢复的次生林。(6)乔木层Shannon-wiener指数和 Simpson指数均表现为自然恢复的次生林显著大于两个人工林,丰富度指数和均匀度指数表现为油松人工林最大;灌木层4个多样性指数均表现为油松人工林最大;草本层的丰富度指数、Shannon-wiener 指数和 Simpson 指数均表现为油松人工林较大,均匀度指数没有显著差异。结论:人工林恢复速度大于自然恢复的次生林,但自然恢复的次生林更新能力更强,且更有利于多样性的保存。两个人工林逐渐由常绿针叶林演替为以常绿针叶树为主的针阔混交林,自然恢复的次生林演替为以常绿阔叶树为主的针阔混交林。     

深圳南山区天然森林群落多样性及演替现状

对南山区5个主要天然森林群落(铁榄群落、鼠刺 降真香群落、鸭脚木群落、假苹婆群落、水翁 假苹婆群落)的组成结构及物种多样性进行分析,并与相邻的香港地区地带性森林群落(黄桐群落)作比较。结果表明,依照亚热带及南亚热带森林群落演替规律,南山区天然林处于不同的演替发育阶段：铁榄群落处于演替第3阶段;鼠刺 降真香群落处于第4阶段;其它3个群落处于第5阶段,均未达到稳定的顶极群落阶段。随着铁榄群落、鼠刺 降真香群落、鸭脚木群落、假苹婆群落、水翁 假苹婆群落这个演替序列,物种丰富度的变化规律是：先逐渐上升,到达一个峰值,再缓慢下降。Shannon-Wiener指数和Pielous均匀度指数的变化规律与物种丰富度相同,Simpson指数变化曲线与这些指数相反。但这些指数反映的结果是一致的。综合多个指数分析,鸭脚木群落物种多样性最大,即当群落中阳生性树种与中生性树种优势度相差不大时。群落具有最大的物种多样性。多样性比较结果显示,南山森林群落物种多样性大大低于香港黄桐群落。5个群落的Shannon—Wiener指数在2．04～2．953之间,明显低于黄桐群落,其Shannon—Wiener指数为4．74;Simpson指数0．1～0．268,黄桐群落为0．05;Pielous均匀度指数64．2％～74％,黄桐群落为79％。南山森林群落物种多样性水平低下的状况与长期的人类干扰有关,必须尽快采取“封山育林”等相应措施来促进群落的保护和恢复。     

Measuring the local community's participation in the management of community forests in Cameroon

Cameroon revised its forestry policy and included the legal concept of community forests, a concept difficult to develop. This study aims to resolve this difficulty by understanding the concept as it is designed by the Cameroon Ministry of Environment and Forestry (MINEF). To this end, two formulae, the second simpler than the first, were developed to measure the percentage of involvement of the local community in the process of implementing a community forest. A questionnaire constructed to assess the importance of the activities in this process provided the coefficients for the first formula. The questionnaire was administered to five groups representing the possible participants in the implementation process. There are statistically significant differences among the mean ratings of importance by the five groups and for the various activities. Despite the latter differences, the numerical difference between the two formulae is negligible. Correlations of the ranking of the importance of the activities predict successful collaboration among MINEF, conservation project officials, and members of non-governmental organizations (NGOs). In contrast, the local communities are less likely to collaborate with the first three groups. There is a gulf between the communities and outside organizations (Ministry, conservation project officials and NGOs). Strategies for facilitating the process of implementing the community forest are suggested.     

海南岛热带低地雨林刀耕火种弃耕地自然恢复过程中的群落构建

研究群落构建机制是群落生态学的一个重要目标, 群落动态过程中的构建规律对于了解群落演替机理有重要的作用。该文以海南岛刀耕火种干扰后自然恢复的10 hm ²热带低地雨林为研究对象, 通过比较不同恢复阶段的次生林(15年、30年和60年)和老龄林在幼苗、幼树和成年树群落的物种组成, 揭示次生演替过程中的群落构建规律。研究结果表明, 老龄林中不同径级群落的物种多样性及不同径级间的物种相似度显著高于各恢复阶段的次生林, 但优势种在群落中的比例低于各恢复阶段的次生林。随着自然恢复过程的进行, 次生林群落物种组成与老龄林的相似性也逐渐增大, 支持演替平衡理论。所有恢复阶段样地中幼苗的个体、物种丰富度和基于多度涵盖估计量(ACE)都低于幼树和成年树群落, 幼苗层物种组成与幼树、成年树也有较大差异, 说明新增到幼苗群落可能是一个难于预测的过程。研究结果说明了确定过程和随机过程共同决定了次生演替的群落构建。     

山西庞泉沟自然保护区森林群落物种多样性

在对山西庞泉沟自然保护区森林群落进行数量分类的基础上,运用丰富度指数、物种多样性指数和均匀度指数对保护区内森林群落的物种多样性进行了研究,并对森林群落各层片之间的物种多样性进行了相关性分析.结果表明:(1)森林群落15个群丛的丰富度指数、物种多样性指数和均匀度指数能很好地反映各群丛多样性变化规律.(2)各群丛的丰富度指数和物种多样性指数总体上呈现草本层＞灌木层＞乔木层,草本层的均匀度最小,大多数森林群落乔木层和灌木层的均匀度比较接近.(3) Patrick指数、Simpson指数、Shannon指数以及Pielou指数和Alatalo指数之间表现极显著差异性(P＜0.01).(4)群丛3(华北落叶松-土庄绣线菊+美蔷薇-东方草莓群丛)灌木层和草本层之间呈显著负相关(r=-0.643,P＜0.05);群丛8(白桦+山杨-灰栒子+美蔷薇-中亚苔草群丛)乔木层和灌木层呈显著负相关(r=-0.458,P＜0.05),灌木层和草本层则呈显著正相关(r=0.404,P＜0.05);群丛11(白杄-中亚苔草+烟管头草)的乔木层和草本层之间呈显著负相关(r=-0.949,P＜0.05).