海南岛霸王岭不同热带森林类型的种-个体关系

 比较分析了海南岛霸王岭自然保护区核心区热带低山雨林、山地雨林、云雾林、山地矮林等4种热带森林类型中不同大小径级树木的物种—个体关系。结果表明：各种植被类型中物种数与个体数对数成线性关系是一种普遍现象,且不受调查树木的径木级影响。在相同个体数的条件下,累积物种数随海拔增高而逐渐减少,也即物种数由热带低山雨林、山地雨林、云雾林到热带山地矮林逐渐减少。对于各种植被类型的种—多度关系,单个体、双个体的物种有相当高的比例,其后一般依个体数的增加,而逐渐降低物种的出现频率,呈典型的倒J型曲线,而且这一比例随树木径级的增加而增加。     

海南霸王岭热带山地雨林森林循环与树种多样性动态

通过对海南岛霸王岭热带山地雨林的调查 ,研究了热带山地雨林树种多样性特征随森林循环的动态变化规律。结果表明 :( 1 )热带山地雨林森林循环不同阶段斑块在森林景观中所占的面积比例分别是 :林隙阶段 ( G)占 38.5 0 % ,建立阶段 ( B)占 2 8.5 0 % ,成熟阶段 ( M)占 2 7.0 0 % ,衰退阶段 ( D)占 6 .0 0 %。 ( 2 )热带山地雨林中乔木树种的密度随森林循环的变化趋势是由 G→B→M呈现出逐渐增加的趋势 ,以成熟阶段达到最大 ,而到衰退阶段又趋于下降。灌木树种则表现出 G阶段斑块的密度最大 ,B阶段的最小 ,从 B到 M有所增加 ,到 D又稍有下降。 ( 3)热带山地雨林中不同高度级和不同径级的树木的密度在森林循环的不同阶段表现出不同的增减趋势 ,其随森林循环过程呈现出的动态变化可能与不同阶段斑块内的空间、环境及物种生物学特性有关。 ( 4 )热带山地雨林中树木的平均胸径、平均高、平均胸高断面积、平均单株材积随森林循环过程呈现出不断增加的趋势 ,其中平均胸径和平均高随森林循环的变化较为平缓 ,而平均胸高断面积和平均单株材积之变化较为陡急。 ( 5 )热带山地雨林森林循环不同阶段的物种多样性指数不同 ,其中 G和 B阶段的物种丰富度和多样性指数值较接近 ,M阶段的物种丰富度达到最大 ,D阶段则最小。     

海南岛霸王岭热带季雨林树木的死亡率

树木死亡是调节群落组成和结构的一种方式, 在森林生态系统动态中发挥着重要作用。该文在对海南岛霸王岭热带季雨林群落大量调查和树种功能群划分研究的基础上, 探索了热带季雨林群落及其不同功能群树木的死亡率及其随径级和环境条件的变化规律。结果表明: 海南岛霸王岭热带季雨林群落内树木死亡率的变化范围为3.42%-18.71%, 平均值为7.60%。按照功能群比较, 乔木死亡率显著高于灌木, 落叶树种死亡率高于常绿树种, 但具刺树种死亡率显著低于无刺树种。按照树木径级划分, 5-30 cm径级范围的死亡率均超过10%, 最高值出现在5-10 cm径级范围, 在相同径级范围内比较时, 落叶树种在 胸径(DBH ) < 5 cm时的死亡率显著高于常绿树种, 而在其他径级范围内, 二者之间无显著差异, 具刺和无刺树种的死亡率在所有径级范围内均无显著差异。乔木死亡率与群落距河流距离具有显著的相关性, 距离河流越远死亡率越高; 落叶树种和无刺树种则与坡位存在显著的相关性, 坡上部的死亡率显著高于坡中部。热带季雨林内树木的死亡率与其所处的群落生境有关, 较干旱的生境是导致树木死亡率较高的重要原因。     

海南中部山区天然林群落结构与多样性变化

为了解海南中部山区天然林群落结构与多样性变化规律,对五指山山地雨林原始林、尖峰岭低地雨林、吊罗山山地雨林、霸王岭云雾林次生林内建成的各1600 m²样地进行常年监测,基于2012—2020年监测数据,从群落结构、树木生长、树木死亡、物种多样性等方面分析群落近8年动态特征。结果表明：2012—2020年,(1)五指山山地雨林、尖峰岭低地雨林的径级结构与树高结构均呈倒“J”型,吊罗山山地雨林、霸王岭云雾林的径级结构呈倒“J”型,树高结构呈近“L”型;随着时间的推移,群落结构更加复杂。(2)小径级个体树高生长速率较快,随胸径增加树高生长速率降低,胸径生长速率升高;死亡个体数量随胸径的增加而减少,表现出小径级个体对阳光等资源的强烈竞争。(3)翻白叶(Pterospermum heterophyllum)、岭南山竹子(Garcinia oblongifolia)、四蕊三角瓣花(Prismatomeris tetrandra)、海南山矾(Symplocos hainanensis)种群变化率分别为-6.07%、+7.10%、+12.52%、+14.29%,种群变化率均大于5%...     

海南岛热带云雾林地上生物量分布规律

生物量是森林最为重要的生态系统功能之一,是物质循环及能量流动的基础。以海南岛尖峰岭、霸王岭和黎母山热带云雾林为对象,调查群落内胸径在1 cm以上的植物胸径和高度;结合异速生长模型,比较3个林区热带云雾林地上生物量随样方大小、树木径级和高度级的变化规律。结果表明:不同样方大小内,3个林区热带云雾林的地上生物量变化规律相同,受降水和温度的影响,尖峰岭和黎母山热带云雾林的地上生物量均显著高于霸王岭。尖峰岭、霸王岭和黎母山热带云雾林地上生物量主要分布于胸径30 cm的植株,分别占33.0%、32.1%和52.8%。尖峰岭和霸王岭热带云雾林的地上生物量主要分布于高度7 m的植株,分别占79.9%和70.1%;而黎母山热带云雾林的地上生物量主要分布于高度9 m的植株,占87.7%;各个径级和高度级上,3个林区热带云雾林的变化规律一致,地上生物量都主要集中在较大的径级和高度级。     

后河自然保护区珍稀濒危植物群落乔木层结构特征

对1hm^2固定样地内的亚热带常绿落叶阔叶混交林乔木层树种的胸径级结构和高度级结构以及按径经对乔木树种多样性和均匀度进行了研究。结果显示;群落内乔木树种数和个体数堕落有径级和高度级增加呈下降趋势。树种数和个体数之间存在显著正相关关系。胸径面积之和随胸径级增加呈波动状态,而随高度级的增加呈先升后降的变化。群落的多相关性一指数和均匀度指数都较高,群落内优势种明显,各种的多度差异较小,群落结构较为稳定,其中珍稀植物在各个胸径级和高度级内的树种数和个体数都较高,群落的更新良好。幼苗补充充足,珍稀树种幼苗丰富度和多度较高。     

海南岛霸王岭垂直带热带植被物种多样性的空间分析

以常用的Shannon-Wiener指数,Simpson指数以及新近提出的两个非参数指数(Chao多样性指数和二阶刀切法多样性指数),计测了海南岛霸王岭垂直带上不同植被类型(包括热带低山雨林、热带山地雨林、热带云雾林、热带山地矮林)的物种多样性.在此基础上,借助地理信息系统的空间分析技术,模拟绘制了整个梯度的多样性变化谱.总体而言,样带下部的物种多样性高于上部,或者说热带低山雨林与热带山地雨林的物种多样性高于热带云雾林与热带山地矮林,而南部稍高于北部.这种基于插值方法的空间分析技术为探索植被结构分析提供了一条新的途径.     

海南岛霸王岭热带山地雨林木质藤本垂直结构特征

木质藤本植物是热带森林结构和功能的重要组分,但对于其垂直分布的研究较少。通过对海南岛霸王岭热带山地雨林坡地8条样带内胸径≥0.5cm的攀援木质藤本进行调查,比较分析了其多度、物种丰富度、径级结构、攀援方式组成、物种组成的垂直结构特征。结果表明:(1)随着高度级增加,木质藤本多度和物种丰富度都呈现出一种先增加后降低的单峰型曲线变化规律。(2)随着高度级增加,木质藤本个体趋于分布在更大径级。在森林底层(05m)和林冠层(≥15m)分别以0.51cm和≥2cm径级的木质藤本占优。(3)不同高度级间,不同攀援方式木质藤本个体比例存在显著差异。主茎缠绕类木质藤本在各高度级都占优势,卷须类木质藤本个体比例随高度增加显著降低,根攀类木质藤本呈现相反趋势。(4)随着高度级增加,木质藤本物种优势度明显发生变化。总体来看,木质藤本呈现出一种复杂、有序的垂直结构,这可能决定其对森林动态的影响。     

海南岛霸王岭垂直带热带植被物多样性的空间分析

以常用的Shannon-Wiener指数,Simpson指数以及新近提出的两个非参数指数（Chao多样性指数和二阶刀切法多样性指数）,计测了海南岛霸王岭垂直止不同植被类型（包括热带低山雨林、热带山地雨林、热带云雾林、热带山地矮林）的物种多样性。在此基础上,借助地理信息系统的空间分析技术,模拟绘制了整经度的多样性变化谱。总体而言,样带下部的物种多样性高于上部,或者说热带低山雨林与热带山地雨林的物种多样性高于热带云雾林与热带山地矮林,而南部稍高于北部。这种基于插值方法的空间分析技术为探索植被结构分析提供了一条新的途径。     

海南霸王岭热带山地雨林林隙更新规律的研究

通过对海南岛霸王岭自然保护区原始热带山地雨林中林隙和非林隙林分的调查,分析了海南岛热带山财雨林中主要树种在林隙内外的数量特征、树各对林隙的更新反应和树种多样性的变化规律。结果表明：（１）不同树林隙内和非隙林分中出现的频度、密度和显著度不同,从而表现出其重要值的不同,根据不同树种在林隙内外重要值位序的差异大小,将海南热带山地雨林中树各划分为７种类型：即（１）只出现于林隙中,（２）只出现于非林隙林分中     

西双版纳青梅林的群落学研究

本文对分布在西双版纳勐腊县南部以龙脑香科植物版纳青梅为标志树种的热带森林作了群落学分析,认为它具有热带雨林的结构和基本特征,在性质上属于热带季节雨林。由于分布海拔偏高和生境特殊,它的上层乔木几乎常绿,在外貌上与望天树林和本地区典型的季节雨林有一定差异,在区系组成上向山地雨林过渡,它表现为一种季节雨林向山地雨林过渡的类型,同时也是一种热带北缘地区季节雨林的海拔极限类型。     

达维台风对海南尖峰岭热带山地雨林群落的影响

 海南岛地处我国台风的频发地带, 台风是影响海南岛热带雨林的一个重要的自然干扰因子。该文对2005年达维台风前后海南尖峰岭热带山地雨林天然次生林2 600 m²固定样地的物种组成、胸高断面积、植株数目、风倒木的影响因子、物种多样性、生物量变化及碳储量归还进行比较分析。结果显示, 台风后森林内产生大量的风倒木、断枝和落叶, 导致群落郁闭度减少、透光性增强, 并产生大量的林窗。台风后群落的组成结构发生显著变化, 受损株数达514株(占总株数26.1%); 其中风倒木比例较大, 达206株(占总株数10.5%)。方差分析结果显示, 受台风影响产生的风倒木与未明显受损树木的胸径面积、树高和木材密度均无显著差异; 但与树种组成有较紧密的关联, 对乔木层、幼树层和下木层造成的损害存在种类上的明显差异。台风产生的损害可以分为直接性损害和间接性损害两种: 1)直接性损害主要作用于乔木层, 造成大径级植株严重受损; 部分树种重要值降低, 变成伴生种, 或者次优势种和原有优势种成为共同优势种; 2)间接性损害主要通过风倒木作用于幼树层和下木层, 产生的倒木、断枝和落叶压倒其它植株, 表现为小面积范围内的个体死亡, 甚至有种类消失; 部分优势种的个体数减少较多, 但占该种群所有个体数目的比例较小。乔木层的Shannon-Wiener和Simpson多样性指数均略有下降, 而幼树层和下木层均略有上升, 但3个林层均表现为不同程度的种类消失和一些种类的个体数目减少。此次台风还造成该样地至少占台风前总生物量10.42%的生物量归还给林地, 并对森林生态系统碳循环产生重大影响。     

Fire survival of lowland tropical rain forest trees in relation to stem diameter and topographic position

The objective of this study was to relate patterns in forest structure, tree species diversity, and tree species composition to stem diameters and topography in unburned, once burned and twice burned lowland dipterocarp rain forests in East Kalimantan, Indonesia. To do this four unburned old growth forests were compared with three forests that burned once (1997/1998) and three forests that burned twice (1982/1983 and 1997/1998). Fire resulted in a strong reduction of climax tree density which was negatively related to tree diameter. However, a disproportionate reduction in small diameter understorey climax tree species occurred only after repeated fires. Climax tree species in both burned forest types were most common in swamps, river valleys and on lower slopes, while their density was much lower on places higher along hillsides. In unburned forest the opposite was observed, with climax tree density increasing steadily from swamp and river valleys to upper slopes and ridges. In contrast to climax trees, pioneer trees were abundant throughout the burned forest, with highest numbers on hill sides and ridges. Our results indicate that both diameter and topographic position of trees strongly affect their fire survival chances in tropical lowland forests.     

滇南勐宋热带山地雨林的物种多样性与生态学特征

 研究了鲜为人知的滇南勐宋地区的原始山地雨林植被, 根据分布生境、群落结构和种类组成特征,可将该山地雨林区分为沟谷和山坡两个类型, 分别定义为八蕊单室茱萸(Mastixia euonymoides)-大萼楠(Phoebe megacalyx)林和云南拟单性木兰(Parachmeria yunnanensis)-云南裸花(Gymnanthes remota)林。该山地雨林的外貌仍以单叶、革质、全缘、中叶为主的常绿中、小高位芽植物组成为特征,层间木质藤本植物仍较丰富,草本高位芽植物和附生植物丰富,但板根和茎花现象少见,属于热带山地垂直带上低山雨林或山地雨林植被类型。与该地区的典型热带季节雨林和赤道热带雨林相比, 勐宋的山地雨林群落中的大、中高位芽植物和藤本高位芽植物比例相对减少, 小、矮高位芽植物和草本高位芽植物比例相对增加,单叶、革质、非全缘叶和小叶比例相对增加,板根现象少见。与中国热带北缘-南亚热带地区（季风）常绿阔叶林比较, 勐宋的山地雨林有较多的附生植物和草本高位芽植物,相对较少的小高位芽植物和矮高位芽植物,小叶比例亦较少,非全缘叶和革质叶比例相对较低。故勐宋山地雨林是滇南热带北缘山地的一种较湿润生境的植被类型, 与所谓的季风常绿阔叶林不同。在物种多样性上,勐宋热带山地雨林在单位面积植物种数上并不比该地区的热带季节雨林低, 物种多样性指数与低丘季节雨林相当,比沟谷季节雨林低, 明显高于季风常绿阔叶林。     

“西双版纳热带山地雨林的植物多样性研究”的一些问题讨论

该文针对“西双版纳热带山地雨林的植物多样性研究”论文中存在的一些问题进行了讨论。原文所依据的6个调查样地, 从其分布海拔、生境、群落的生态外貌特征、植物区系组成及单位面积植物种数的统计上反映出它们并非都属于同样的植被类型,即原文所称的热带山地雨林,而可能分别属于《云南植被》中所应用的热带季节雨林的次生林群落(样地I和II)、季风常绿阔叶林群落(样地V和VI)及类似于苔藓常绿阔叶林(样地III和IV)的群落类型。由于这些样地代表了不同的植被类型, 导致在对这些样地的植物多样性特征的比较上出现较大差异。对原文在资料分析和与其它森林群落植物多样性的比较上存在的一些问题也作了讨论。原文的研究结果显示了西双版纳不同海拔高度上森林植物群落的物种多样性特征,但并不能全部运用于该地区的热带山地雨林这一特定植被类型。     

Effects of selective logging on tree diversity,composition and plant functional type patterns in a Bornean rain forest

Abstract. The effects of selective logging on tree diversity, changes in tree species composition and plant functional types were studied with the use of seven permanent plots in virgin and in logged forest. All plots were located in a lowland dipterocarp rain forest in East Kalimantan on the island of Borneo. Just after logging and during the following 20 yr tree diversity measured as Fishers’α was not significantly affected in logged forest plots. Temporal shifts in tree species composition were analysed with Principal Component Analysis (PCA). Logged forest plots had much larger changes over time than virgin forest plots. In the smallest diameter class, some logged forest plots showed a distinct trajectory in PCA space compared to virgin forest plots, while in larger diameter classes movement of logged plots in PCA space was random. This suggests that there is no predetermined community to which logged forest plots tend to shift when recovering from logging. We found a significant negative correlation between diameter increments and the species‐specific wood densities of tree species. Species‐specific wood density and potential tree height were used to assign species to five PFTs. As expected, logging increased the fraction of softwood stems in small diameter classes. In the largest diameter classes (≥ 50 cm DBH) a strong decrease of softwood emergent stems was found in logged forest plots. After more than 20 yr no recruitment was found of softwood emergent stems in selectively logged forest.     

ECOLOGICAL CONSTRAINTS ON WOOD DENSITY IN A TROPICAL MONTANE RAIN FOREST

In a Costa Rican tropical lower montane rain forest the wood densities of canopy tree species are related to the windiness of their preferred habitats, and to their abilities to tolerate shade. Shade-intolerant species tend to have less dense wood than shade-tolerant species from the same habitat. Species characteristic of windy sites tend to have denser wood than species characteristic of sheltered habitats. Stand mean wood density, the average of species’ wood densities weighted by their proportional contributions to stand basal area, increases with exposure to the wind. These trends in wood density should at least partially counteract the damaging effects of wind on exposed sites. Since investment in wood must come at the expense of growth elsewhere, such trends in wood density may help explain the small stature of elfin forest and montane thicket formations in tropical mountains.     

Vegetation Structure,Composition, and Species Richness Across a 56‐year Chronosequence of Dry Tropical Forest on Providencia Island,Colombia1

We compared vegetation structure and species richness across a 56‐yr chronosequence of six replicated age classes of dry tropical forest on the island of Providencia, Colombia, in the Southwest Caribbean. Stand age classes were determined using sequential, orthorectified panchromatic aerial photos acquired between 1944 and 1996 and Landsat 7 ETM + satellite imagery from 2000. Along the chronosequence we established 59 plots of 2 × 50 m (0.01 ha) to document changes in species richness, basal area, tree height, stem density, and sprouting ability. All woody trees and shrubs >2.5 cm diameter at breast height (DBH) were censused and measured. Although woody species density reached a peak in stands from 32 to 56 yr old, rarefaction analysis showed that species richness increased linearly with stand age and was highest in stands 56 yr old or greater. Nonparametric, abundance‐based estimators of species richness also showed positive and linear associations with age. Basal area and mean tree height were positively associated with age since abandonment, while sprouting ability showed a negative relationship. Our results indicate rapid recovery of woody species richness and structural characteristics along this tropical dry forest chronosequence.     

Tree species diversity of tropical forest vegetation in Xishuangbanna, SW China

Tree species diversity of four tropical forest vegetation types was investigated in Xishuangbanna, southwestern China. These are: tropical seasonal rain forest, tropical montane rain forest, evergreen broad-leaved forest and monsoon forest over limestone. A total of 17 samples were taken and four species diversity indices were calculated: Shannon-Wiener's H, the complement of Simpson's index, d, Fisher's and evenness index E. The results reveal the long-tailed rank/abundance diagrams of these forests. However, this feature is greatly reduced in the samples of monsoon forest over limestone. Tropical seasonal rain forest shows the highest tree species diversity of all four vegetation types. Owing to the variation of microenvironment, diversity values within the same vegetation type vary between the samples from different patches. The tree species diversity of single-dominant rain forest is not significantly lower than that of mixed rain forest, because the dominant species of some single-dominant rain forests are principally in the emergent layer. This is composed of sparse and huge trees of one species and, consequently, creates a unique canopy architecture and more heterogeneous microenvironments for the more diversified species composition under the emergent layer. The occurrence of tree species with small population sizes, particularly of species represented by only one individual, is highly correlated with the tree species diversity of the local forest vegetation. They are crucial elements in the richness of local biodiversity.