滇东菌子山喀斯特森林的植被类型及其特征

菌子山喀斯特森林区位于云南东部师宗县, 在植被区划上属滇中、滇东高原半湿润常绿阔叶林与云南松(Pinus yunnanensis)林区。该片森林以次生林为主, 是这一植被区东部边缘残留森林的典型代表。为揭示菌子山喀斯特森林类型组成及其群落特征, 该研究对该森林区开展了系统的样方调查, 记录了群落的物种组成、数量特征、生境信息等。通过对29个样方的调查数据的分析, 基于群落学-生态学分类原则和最新的中国植被分类系统修订方案, 该喀斯特森林可划分为4个植被型, 16个群系和27个群丛。该研究对每个群丛的特征进行了描述, 提供了所有样方的原始数据。     

Do lianas shape ant communities in an early successional tropical forest?

Almost half of lowland tropical forests are at various stages of regeneration following deforestation or fragmentation. Changes in tree communities along successional gradients have predictable bottom‐up effects on consumers. Liana (woody vine) assemblages also change with succession, but their effects on animal succession remain unexplored. Here we used a large‐scale liana removal experiment across a forest successional chronosequence (7–31 years) to determine the importance of lianas to ant community structure. We conducted 1,088 surveys of ants foraging on and living in trees using tree trunk baiting and hand‐collecting techniques at 34 paired forest plots, half of which had all lianas removed. Ant species composition, β‐diversity, and species richness were not affected by liana removal; however, ant species co‐occurrence (the coexistence of two or more species in a single tree) was more frequent in control plots, where lianas were present, versus removal plots. Forest stand age had a larger effect on ant community structure than the presence of lianas. Mean ant species richness in a forest plot increased by ca. 10% with increasing forest age across the 31‐year chronosequence. Ant surveys from forest >20 years old included more canopy specialists and fewer ground‐nesting ant species versus those from forests <20 years old. Consequently, lianas had a minimal effect on arboreal ant communities in this early successional forest, where rapidly changing tree community structure was more important to ant species richness and composition.     

The effects of forest conversion to oil palm on ground‐foraging ant communities depend on beta diversity and sampling grain

Beta diversity – the variation in species composition among spatially discrete communities – and sampling grain – the size of samples being compared – may alter our perspectives of diversity within and between landscapes before and after agricultural conversion. Such assumptions are usually based on point comparisons, which do not accurately capture actual differences in total diversity. Beta diversity is often not rigorously examined. We investigated the beta diversity of ground‐foraging ant communities in fragmented oil palm and forest landscapes in Sabah, Malaysia, using diversity metrics transformed from Hill number equivalents to remove dependences on alpha diversity. We compared the beta diversities of oil palm and forest, across three hierarchically nested sampling grains. We found that oil palm and forest communities had a greater percentage of total shared species when larger samples were compared. Across all grains and disregarding relative abundances, there was higher beta diversity of all species among forest communities. However, there were higher beta diversities of common and very abundant (dominant) species in oil palm as compared to forests. Differences in beta diversities between oil palm and forest were greatest at the largest sampling grain. Larger sampling grains in oil palm may generate bigger species pools, increasing the probability of shared species with forest samples. Greater beta diversity of all species in forest may be attributed to rare species. Oil palm communities may be more heterogeneous in common and dominant species because of variable community assembly events. Rare and also common species are better captured at larger grains, boosting differences in beta diversity between larger samples of forest and oil palm communities. Although agricultural landscapes support a lower total diversity than natural forests, diversity especially of abundant species is still important for maintaining ecosystem stability. Diversity in agricultural landscapes may be greater than expected when beta diversity is accounted for at large spatial scales.     

茂县土地岭植被恢复过程中物种多样性动态特征

植被恢复是退化生态系统重建的重要途径,植被恢复过程物种多样性的变化反映了植被的恢复程度.通过群落调查和多样性分析,研究了岷江上游土地岭植被恢复过程中群落物种多样性特征.结果表明： 恢复过程中6类不同类型群落分别表现其对于不同环境特征、干扰及更新方式等的响应;森林是较灌丛更适合当地环境状况的植被类型;人工恢复无干扰和轻度干扰群落的多样性相对较高,是较好的恢复模式.重度干扰使得1年生植物与地下芽植物比例增加,其它口食性较好的多年生草本减少.较强的干扰是群落无法更新、长期处于灌丛阶段且多样性较低的重要原因.本地区人工恢复群落在更新进程和多样性维持上优于自然更新群落,种植华山松加速了本地区植被演替进程.建议以适合恢复区域的多种恢复配置方式进行造林,并避免较强干扰,可以加速群落演替进程并保持恢复群落较高的物种丰富度与多样性.     

基于分层的典型中亚热带天然阔叶林分局部生物多样性

选择福建万木林保护区内两块典型中亚热带天然阔叶林样地为对象,按分层和不分层两种情形,研究了小尺度(20m)范围内各组成树种的单物种-面积关系(individual species-area relationship,ISAR),以探讨局部生物多样性格局及其维持机制。结果表明,两个群落的乔木层都可以划分出受光层和非受光层两个亚层。以受光层林木为圆心进行ISAR分析,发现在小尺度范围大多数受光层林木为局部生物多样性的中性种,只有个别树种在个别尺度上有显著的促进或排斥作用。研究途径避免了对非随机作用在维持局部生物多样性中的相对重要性的高估。不分层时,乔木层内同样以中性树种为主。研究结果支持小尺度范围内调查的典型中亚热带天然阔叶林的物种多样性由中性作用主导的结论。     

古田山不同干扰程度森林的群落恢复动态

森林采伐后次生林的恢复过程对于生物多样性的保护和生态系统功能的重建具有重要意义。作者以古田山不同干扰程度的12个1 ha 森林样地为研究对象, 运用群落多元统计方法, 探讨了自然恢复过程中森林群落组成及物种多样性的动态变化及趋势。结果表明: 不同恢复阶段森林样地的群落组成存在显著性差异, 而同一恢复阶段的样地具有高度的相似性。物种丰富度随恢复进程有增加的趋势, 但各阶段差异并不显著; 物种均匀度除人工林较低以外, 其他恢复阶段之间无显著性差异。不同恢复阶段研究样地的群落组成及物种多样性的差异主要存在于林冠层。灌木及更新层具有各自的指示种, 人工林的指示种为落叶灌木或阳性乔木, 幼龄次生林的指示种为常绿灌木或小乔木, 老次生林的指示种为亚乔木层常绿树种, 老龄林的指示种为林冠层树种。上述结果表明古田山不同人为干扰程度森林群落的物种多样性具有较强的自我恢复能力。尽管物种组成难以预测, 但处于同一恢复阶段的森林, 其幼树的生活型组成呈现出一致的变化趋势。     

Fate of epiphytes on phorophytes with different architectural characteristics along the perturbation gradient of Sabal mexicana forests in Veracruz,Mexico

Question: Vascular epiphytes and hemiepiphytes (E/HE) in neotropical forests account for a large fraction of plant richness, but little is known of how the interplay between phorophyte architectural characteristics and habitat perturbation affect communities of E/HE. Location: Sabal mexicana forests in a coastal area of Veracruz, Mexico. Methods: We compared communities of E/HE on phorophytes with different architectural characteristics – the palm S. mexicana and non‐palm phorophytes – in three environments: conserved sites, perturbed sites and small regenerated forest fragments. We combined traditional (abundance, species richness, similarity and complementarity indices) and more recent (phylogenetic diversity) metrics to describe the communities of E/HE. Results: Overall, we recorded 924 E/HE individuals (nine families, 16 genera and 21 species). The abundance and species richness of E/HE was higher on palms than on non‐palm phorophytes. Abundance‐based complementarities between phorophytes and sites were high. We detected clear changes in community structure of E/HE with habitat perturbation, but there were no effects on the phylogenetic diversity of the E/HE community. Palm phorophytes hosted a more phylogenetically diverse community of E/HE than did non‐palm phorophytes. Conclusions: Palm phorophytes are key elements supporting the conservation of resilient communities of E/HE in S. mexicana forest. Habitat fragmentation has a strong effect on the structure of the E/HE community in S. mexicana forests. Ferns are the group of epiphytes most severely affected by habitat perturbation, but we detected no significant effect on the phylogenetic diversity of the community.     

Edge effects on palm diversity in rain forest fragments in western Ecuador

At the edges of tropical rain forest fragments, altered abiotic and biotic conditions influence the structure and dynamics of plant communities. In Neotropical rain forests, palms (Arecaceae) are important floristic and ecological elements. Palms’ responses to edge effects appear to be idiosyncratic and to depend on the level of disturbance at edges. This paper explores how variation in forest structure at the edges of two old-growth forest fragments in a tropical rain forest in western Ecuador affects palms of different species, life-forms, and size classes. We investigate (1) how edge effects influence the relative proportion of palm adults and juveniles, (2) how distance from the forest edge affects palm density and species richness, (3) how altered forest structure along edges affects palm density. We found that at edges (1) palm communities had a lower proportion of adults relative to juvenile individuals compared to continuous forests, (2) the density of two species of palms and the overall species richness of the palm community tended to decrease toward the edges within forest fragments, and, (3) altered forest structure decreased the density of adult palms. Hence, edge effects on palms were controlled by the degree of modification of the forest structure, and by species responses to edge-related disturbance.     

Vertical stratification of ichneumonid wasp communities: the effects of forest structure and life‐history traits

Parasitoid wasp communities of the canopy of temperate forests are still largely unexplored. Very little is known about the community composition of parasitoids between canopy and understory and how much of this difference is related to forest structure or parasitoid biological strategies. In this study we investigated upon the difference in the community composition of the parasitic wasps Ichneumonidae between canopy and understory in a lowland temperate forest in northern Italy. We used general linear models to test whether parasitic strategy modifies species vertical stratification and the effect of forest structure. We also tested differences in β‐diversity between canopy and understory traps and over time within single forest layers. We found that stand basal area was positively related to species richness, suggesting that the presence of mature trees can influence local wasp diversity, providing a higher number of microhabitats and hosts. The ichneumonid community of the canopy was different from that of the understory, and the β‐diversity analysis showed higher values for the canopy, due to a higher degree of species turnover between traps. In our analyses, the vertical stratification was different between groups of ichneumonids sharing different parasitic strategies. Idiobiont parasitoids of weakly or deeply concealed hosts were more diverse in the understory than in the canopy while parasitoids of spiders were equally distributed between the two layers. Even though the ichneumonid community was not particularly species‐rich in the canopy of the temperate forests, the extension of sampling to that habitat significantly increased the number of species recorded.     

Peatland forests are the least diverse tree communities documented in Amazonia,but contribute to high regional beta‐diversity

Western Amazonia is known to harbour some of Earth's most diverse forests, but previous floristic analyses have excluded peatland forests which are extensive in northern Peru and are among the most environmentally extreme ecosystems in the lowland tropics. Understanding patterns of tree species diversity in these ecosystems is important both for quantifying beta‐diversity in this region, and for understanding determinants of diversity more generally in tropical forests. Here we explore patterns of tree diversity and composition in two peatland forest types – palm swamps and peatland pole forests – using 26 forest plots distributed over a large area of northern Peru. We place our results in a regional context by making comparisons with three other major forest types: terra firme forests (29 plots), white‐sand forests (23 plots) and seasonally‐flooded forests (11 plots). Peatland forests had extremely low (within‐plot) alpha‐diversity compared with the other forest types that were sampled. In particular, peatland pole forests had the lowest levels of tree diversity yet recorded in Amazonia (20 species per 500 stems, Fisher's alpha 4.57). However, peatland pole forests and palm swamps were compositionally different from each other as well as from other forest types in the region. Few species appeared to be peatland endemics. Instead, peatland forests were largely characterised by a distinctive combination of generalist species and species previously thought to be specialists of other habitats, especially white‐sand forests. We suggest that the transient nature and extreme environmental conditions of Amazonian peatland ecosystems have shaped their current patterns of tree composition and diversity. Despite their low alpha‐diversity, the unique combination of species found in tree communities in Amazonian peatlands augment regional beta‐diversity. This contribution, alongside their extremely high carbon storage capacity and lack of protection at national level, strengthens their status as a conservation priority.     

Disturbance history mediates climate change effects on subtropical forest biomass and dynamics

The responses of forest communities to interacting anthropogenic disturbances like climate change and logging are poorly known. Subtropical forests have been heavily modified by humans and their response to climate change is poorly understood. We investigated the 9‐year change observed in a mixed conifer‐hardwood Atlantic forest mosaic that included both mature and selectively logged forest patches in subtropical South America. We used demographic monitoring data within 10 1 ha plots that were subjected to distinct management histories (plots logged until 1955, until 1987, and unlogged) to test the hypothesis that climate change affected forest structure and dynamics differentially depending on past disturbances. We determined the functional group of all species based on life‐history affinities as well as many functional traits like leaf size, specific leaf area, wood density, total height, stem slenderness, and seed size data for the 66 most abundant species. Analysis of climate data revealed that minimum temperatures and rainfall have been increasing in the last few decades of the 20th century. Floristic composition differed mainly with logging history categories, with only minor change over the nine annual census intervals. Aboveground biomass increased in all plots, but increases were higher in mature unlogged forests, which showed signs of forest growth associated with increased CO₂, temperature, and rainfall/treefall gap disturbance at the same time. Logged forests showed arrested succession as indicated by reduced abundances of Pioneers and biomass‐accumulators like Large Seeded Pioneers and Araucaria, as well as reduced functional diversity. Management actions aimed at creating regeneration opportunities for long‐lived pioneers are needed to restore community functional diversity, and ecosystem services such as increased aboveground biomass accumulation. We conclude that the effects of climate drivers on the dynamics of Brazilian mixed Atlantic forests vary with land‐use legacies, and can differ importantly from the ones prevalent in better known tropical forests.     

Potential Effects of Ateline Extinction and Forest Fragmentation on Plant Diversity and Composition in the Western Orinoco Basin,Colombia

Cattle and agricultural farming in the western Orinoco Basin began in 1555, and since then fragmentation of continuous forest has occurred. We evaluated the effects of the disturbances and the absence of large primates on plant community composition, diversity, and regeneration patterns. Atelines (Lagothrix and Ateles) inhabited the lowlands close to the Andean mountains, but no longer live in fragmented habitats. Their absence may have negative effects on plant populations because atelines play important roles as seed dispersers in neotropical forests, especially for large-seeded plants, which are rarely swallowed by other seed dispersers. We compared 2 1-ha vegetation plots in forest fragments north of the La Macarena Mountains with 7 plots in continuous forest in Tinigua National Park. Both sites share the same climatic conditions and have similar geological origins. There is floristic affinity between forests with similar ecological characteristics; the fragmented forests are also less diverse than the continuous forests. As predicted, the forest fragments have fewer individuals with large seeds. The results suggest that forest fragmentation and local ateline extinctions affect plant communities, reducing diversity and affecting large-seeded plants.     

Patterns in woody species diversity, richness and partitioning of diversity in forest communities of tropical deciduous forest biome

The regressive succession model hypothesizes tropical savanna-woodlands to be a degraded stage of primary deciduous forests. Species diversity, richness and evenness of woody species in savanna-woodlands, secondary deciduous forests and mature deciduous forests of central India were compared to test if the regressive succession explained pattern in species richness, diversity, functional diversity and basal area. At the plot scale (0.1 ha) secondary deciduous forests and savanna-woodlands had similar species diversity, a pattern not consistent with the regressive model of deciduous forest succession, and mature deciduous forests had greater species diversity and richness (p<0.05). When examined at a larger scale or community scale by pooling all plots within a community type, the trend in diversity persisted even with greater effort allocated to sampling of secondary deciduous forests. Species richness at the community scale was greatest in secondary deciduous forest as expected from species area relationship. The communities shared 28 woody species but the species composition was significantly different between the communities. I suggest that conservation of tropical deciduous forests based on regressive succession model is problematic.     

Effects of logging and recruitment on community phylogenetic structure in 32 permanent forest plots of Kampong Thom,Cambodia

Ecological communities including tropical rainforest are rapidly changing under various disturbances caused by increasing human activities. Recently in Cambodia, illegal logging and clear-felling for agriculture have been increasing. Here, we study the effects of logging, mortality and recruitment of plot trees on phylogenetic community structure in 32 plots in Kampong Thom, Cambodia. Each plot was 0.25 ha; 28 plots were established in primary evergreen forests and four were established in secondary dry deciduous forests. Measurements were made in 1998, 2000, 2004 and 2010, and logging, recruitment and mortality of each tree were recorded. We estimated phylogeny using rbcL and matK gene sequences and quantified phylogenetic α and β diversity. Within communities, logging decreased phylogenetic diversity, and increased overall phylogenetic clustering and terminal phylogenetic evenness. Between communities, logging increased phylogenetic similarity between evergreen and deciduous plots. On the other hand, recruitment had opposite effects both within and between communities. The observed patterns can be explained by environmental homogenization under logging. Logging is biased to particular species and larger diameter at breast height, and forest patrol has been effective in decreasing logging.     

Does the composition of Scarabaeidae (Coleoptera) communities reflect the extent of land use changes in the Brazilian Amazon?

Scarab beetles (Coleoptera: Scarabaeidae) have been used to investigate the effects of environmental disturbances on forest structure and diversity. This group is recognized as sensitive to habitat perturbations and ecosystem changes. Here we examine the effects of anthropogenic impacts on Scarabaeidae composition, testing the following hypotheses: (1) Scarab beetle communities react to land use disturbances with predictable trends, (2) disturbed habitats are able to retain only a part of the Scarab beetle community of native forests or late secondary forests; (3) habitats largely differ in terms of species richness, taxonomic diversity and ecological composition, supporting exclusive and indicator species. We selected areas of native forest, agriculture, pasture for extensive livestock and secondary forests in different stages of regeneration. Our results show that the Scarabaeidae species were not indifferent to the gradient of structural changes represented by the studied areas. In fact, their patterns of habitat preference reveals communities more abundant and diverse in pristine habitats. In contrast, disturbed habitats, dominated by agricultural activities and pasture, indicated clear detrimental effects on the abundance of all forest Scarab beetle specialists. On the other hand, the generalist species, mainly associated with open environments, seemed to be favoured by the prevailing conditions induced by agricultural activities. Overall, the composition of the Scarab beetle communities is variable and sensitive to those structural gradients and, therefore, capable of responding as useful ecological indicators for assessing the extent of land use change or degradation.     

湖南八大公山黄杉种群结构和群落特征研究

利用样方法对湖南八大公山黄杉(Pseudotsuga sinensis Dode)群落进行调查,分析黄杉群落的物种组成、区系特征、径级结构和物种多样性。结果显示,群落内共有维管植物132种,隶属于48科89属。群落垂直结构明显,分为乔木层、灌木层和草本层,黄杉是乔木层的优势种,另有檵木(Loropetalum chinense(R.Br.)Oliver)、马尾松(Pinus massoniana Lamb)和油桐(Vernicia fordii(Hemsl.)Airy Shaw)等主要伴生种,檵木为灌木层优势种,两色鳞毛蕨(Dryopteris setosa(Thunb.)Akasawa)为草本层优势种。群落区系组成以泛热带分布和北温带分布为主,具有明显的亚热带向温带过渡的性质。种群年龄结构可分为稳定型向衰退型过渡和衰退型2个类型,样方中幼苗和幼树极度缺失,中龄和老龄个体居多。黄杉、钩栲针阔混交林的物种多样性高于黄杉纯林,其中灌木层的多样性指数最高,乔木层的物种多样性指数最低。群落冠层郁闭度高造成的幼苗缺失可能是影响其濒危的主要原因,建议采取人为干扰创造林窗、加快繁殖技术研究等措施扩大其种群数量。     

Stand structure, species diversity and regeneration of an endemic palm forest on the Seychelles

The ‘Vallée de Mai’ on the island of Praslin in the Seychelles group is a World Heritage Site because of its unique forest vegetation dominated by the palm Lodoicea maldivica. However, despite its great conservation importance, the stand structure, species diversity and regeneration of this forest have not previously been studied. Moreover, the conservation value of the reserve is currently threatened by invading alien plants and limited regeneration of some native species. The species composition of the forest was studied in six permanent plots (1985 and 1998) and along seven trail transects (1997). To explain potential variation in tree regeneration, the light climate within all plots was investigated using hemispherical photographs. The results reveal little change in forest structure, species diversity and regeneration in the permanent plots over the 13‐year period, but some regeneration of most woody species, presence of some alien species and a relatively high species turnover. We found no significant influence of local light climate upon forest structure, species diversity or regeneration. Although the stand characteristics seem to be relatively stable, the permanent plots and transects should be monitored in order to detect future changes in stand structure and to optimize the protection of this unique forest reserve.     

深圳坝光区域自然林及半自然林植物多样性比较

实地调查深圳市坝光区域2个封育状态下的自然林和2个处于恢复状态的荒弃果林半自然林的植物群落结构,测定植物高度、盖度等指标,分析两种类型植物群落组成及多样性特征。结果表明,在群落各层次的种类组成方面,自然林乔木层与灌木层的植物种类数均大于半自然林,半自然林的灌木层与草本层发育也较好,种类丰富;在物种多样性Simpson指数、Shannon-Wiener指数和丰富度指数方面,4个群落的灌木层多样性都较其他2个层次高,说明在人为干扰减小的情况下,灌木的自我更新能力较强。自然林3个群落层次及整体指标等多数高于半自然林,说明自然林植被结构发育较好,各层次种类数更为丰富,各种类个体数及分布更为均匀;而处于恢复状态的半自然林,由于受到人为干扰的印迹未完全消失,乔木层的多样性指数明显低于自然林,但也因为处于恢复状态,灌木层与草本层的恢复使其物种多样性逐渐增高。     

亚热带常绿阔叶林附生地衣凋落物的物种多样性和生物量的边缘效应

地衣是亚热带山地森林系统附生生物类群的重要组成部分之一,对环境变化极其敏感。为了更好地了解附生地衣对森林边缘效应的响应,我们在云南哀牢山地区原生山地常绿阔叶林中,分别在距林缘5m、25m、50m和 100m处设立样地,收集附生大型地衣的凋落物1年;分析附生地衣凋落物的物种多样性和生物量、功能群特征和组成结构对林缘深度变化的响应特征。研究结果显示,边缘效应能够显著提高林缘附生地衣群落的物种多样性和生物量;其发生的距离最深不超过25m。林缘-林内梯度上,不同地衣功能群的响应模式具有各自的特征。排序分析表明仅在5m样地与其他样地之间存在显著差异,指示种分析则发现仅5m样地具有指示种。哀牢山原生林中边缘效应促进林缘附生地衣生长和分布的现象,可能与当地高湿环境削减了地衣的高光损伤以及以叶状和灌状类群为主的地衣个体受到风力破坏的程度相对较低有关。     

西南喀斯特峰丛洼地木本植物群落结构与多样性变化

为了阐明喀斯特峰丛洼地植物群落结构和物种多样性特征及其变化规律,选择西南喀斯特具有代表性的灌木林、次生林和原生林3种植被类型,基于2007年、2012年、2017年3次植被的系统调查,研究了木本植物群落物种组成、群落结构和物种多样性的动态变化。研究结果表明,灌木林2007—2012年减少1个种,2012—2017年减少7属5种;次生林2007—2012年减少1科1属,2012—2017年增加4科7属6种;原生林2007—2012年减少1科4属6种;2012—2017年增加1科3属3种。增加和减少的物种为偶见种或稀有种,引起群落中物种数量的波动。灌木林中黄荆(Vitex negundo)、八角枫(Alangium chinense)重要值均大于10,黄荆占绝对优势;次生林中菜豆树(Radermachera sinica)、灰毛浆果楝(Cipadessa cinerascens)、香椿(Toona sinensis)等物种重要值大于10,占主要优势;原生林的优势种不突出,为多优势种群落。3种植被类型群落的胸径各年份差异显著,平均树高在5年间的差异不显著,10年间达到了显著差异;群落总径级结...