Continental rain forest fragments in Singapore resist invasion by exotic plants

Abstract Aim In general, the plant communities of oceanic islands suffer more from exotic plant invasions than their continental equivalents. At least part of this difference may be contributed by differences in non‐biological factors, such as the antiquity and intensity of human impacts and the absence of internal barriers to dispersal, rather than differences in inherent invasibility. We tested the resistance of species‐rich continental rain forests to plant invasion on a small, continental island that has been subject to prolonged and intensive human impact. Location Singapore is a 683‐km² equatorial island <1 km from the Asian mainland and with a population of 4 million people. It has a continental biota but has been subject to human impacts as intense as on any oceanic island. Methods We sampled twenty‐nine sites in seven vegetation types, ranging from urban wasteland to fragments of primary lowland rain forest. In each sample plot, all plant species were identified, exotic cover was estimated, and a range of environmental variables measured. Additional qualitative surveys for exotic invasion were made in other forest areas in Singapore. The data were analysed by Spearman's rank correlation coefficient. Results The number of exotic species recorded at a site was unrelated to the number of native species. Across all sites, percentage canopy opening had the highest correlation with the number of exotic species, while soil pH (which largely reflects the incorporation of calcareous construction wastes) had the highest correlation if the mangrove sites were excluded. There were no exotics in mangrove forest and only a tropical American, bird‐dispersed shrub, Clidemia hirta (L.) D. Don (Melastomataceae: Koster's Curse), in primary and tall secondary forest patches. The species‐poor early stages of woody plant succession on highly degraded soils were also very resistant to exotic plant invasion. Main conclusions Long‐isolated rain forest fragments in an exotic‐dominated continental island landscape resist invasion by exotic plants, suggesting that the problems on oceanic islands may reflect an inherently greater invasibility. This study also adds to the increasing evidence that the floras of tropical rain forest fragments in South‐east Asia are remarkably resilient on a time‐scale of decades to a century or more.     

Logging,exotic plant invasions,and native plant reassembly in a lowland tropical rain forest

Habitat modification and biological invasions are key drivers of global environmental change. However, the extent and impact of exotic plant invasions in modified tropical landscapes remain poorly understood. We examined whether logging drives exotic plant invasions and whether their combined influences alter understory plant community composition in lowland rain forests in Borneo. We tested the relationship between understory communities and local‐ and landscape‐scale logging intensity, using leaf area index (LAI) and aboveground biomass (AGB) data from 192 plots across a logging‐intensity gradient from primary to repeatedly logged forests. Overall, we found relatively low levels of exotic plant invasions, despite an intensive logging history. Exotic species were more speciose, had greater cover, and more biomass in sites with more local‐scale canopy loss. Surprisingly, though, exotic species invasion was not related to either landscape‐scale canopy loss or road configuration. Moreover, logging and invasion did not seem to be acting synergistically on native plant composition, except that seedlings of the canopy‐dominant Dipterocarpaceae family were less abundant in areas with higher exotic plant biomass. Current low levels of invasion, and limited association with native understory community change, suggest there is a window of opportunity to manage invasive impacts. We caution about potential lag effects and the possibly severe negative impacts of exotic plant invasions on the long‐term quality of tropical forest, particularly where agricultural plantations function as permanent seed sources for recurrent dispersal along logging roads. We therefore urge prioritization of strategic management plans to counter the growing threat of exotic plant invasions in modified tropical landscapes.     

Butterfly Community Composition Across a Successional Gradient in a Human‐disturbed Afro‐tropical Rain Forest

Knowledge of the recovery of insect communities after forest disturbance in tropical Africa is very limited. Here, fruit‐feeding butterflies in a tropical rain forest at Kibale National Park, Uganda, were used as a model system to uncover how, and how fast, insect communities recover after forest disturbance. We trapped butterflies monthly along a successional gradient for one year. Traps were placed in intact primary forest compartments, heavily logged forest compartments with and without arboricide treatment approximately 43 years ago, and in conifer‐clearcut compartments, ranging from 9 to 19 years of age. The species richness, total abundance, diversity, dominance, and similarity of the community composition of butterflies in the eight compartments were compared with uni‐ and multivariate statistics. A total of 16,728 individuals representing 88 species were trapped during the study. Butterfly species richness, abundance, and diversity did not show an increasing trend along the successional gradient but species richness and abundance peaked at intermediate stages. There was monthly variation in species richness, abundance, diversity and composition. Butterfly community structure differed significantly among the eight successional stages and only a marginal directional change along the successional gradient emerged. The greatest number of indicator species and intact forest interior specialists were found in one of the primary forests. Our results show that forest disturbance has a long‐term impact on the recovery of butterfly species composition, emphasizing the value of intact primary forests for butterfly conservation.     

Leaf litter depth as an important factor inhibiting seedling establishment of an exotic palm in tropical secondary forest patches

Intact tropical rainforests on continents and continental islands are considered to be relatively resistant to invasions by introduced plant species, but fragmentation and degradation may render them susceptible, especially to species from predominantly shade-tolerant families with centres of diversity in the tropics, such as palms. We investigated the seedling establishment patterns of the most common exotic palm species in Singapore’s secondary forest patches, the Macarthur palm (Ptychosperma macarthurii), in relation to landscape-level planting intensity, abiotic conditions, and recipient community composition. We first used conditional inference forests to narrow down the set of possible explanatory variables, followed by fitting generalised linear models with the forest patch and individual plots as random intercepts, to account for the nesting of plots within patches and overdispersion, respectively. The number of cultivated adults in the vicinity was not an important variable. Instead, leaf litter was the most important predictor of seedling density. Thick leaf litter in the disturbed and younger secondary forest matrix that surrounds old growth forest patches may therefore serve as a buffer against invasions, especially by small-seeded exotics. However, if adults of exotic species are allowed to establish unchecked, for example along forest trails that lead into the interior of the forested landscape, the seed rain may eventually reach old growth forest where leaf litter is typically thin. Further studies are required to determine if second-generation adults within invaded habitats contribute disproportionately more to propagule pressure than first-generation cultivated plants outside the invaded habitat.     

Exotic plant invasion in the highly degraded upland landscape of Hong Kong, China

Plant communities in the continental tropics have suffered less from exotic plant invasions than their oceanic island counterparts. Most studies have focused on near-pristine communities. By contrast, we examine the resistance of semi-natural continental plant communities in Hong Kong, which have been suffering from chronic and massive human impacts. We compiled a list of all naturalized non-native species recorded in Hong Kong and then sampled the plant communities for exotic species along roadsides, a stream through semi-natural vegetation, and in semi-natural vegetation away from both roads and streams on Tai Mo Shan, Hong Kong’s highest peak (957 m). Similar surveys were repeated in other areas of Hong Kong. More than 162 naturalized exotic plant species have been recorded in Hong Kong. On Tai Mo Shan, 29 exotic species were recorded in roadside vegetation, with the diversity but not percentage cover declining significantly with altitude. Fifteen exotic species were found along the stream, including two not found along the roadside. Only six exotic species were found away from roads and streams, all in unshaded areas disturbed by feral cattle. In all surveys, no exotics were found in closed woody vegetation or in open areas without feral cattle, except for one species. The shade-tolerant tropical Asian tree Syzygium jambos was found invading along some streamsides without anthropogenic disturbance. Despite centuries of massive human impacts, exotic plant invasions in Hong Kong are still largely confined to habitats that suffer from chronic human disturbance. Feral cattle promote invasion where people are absent, but this problem still seems potentially reversible. Only Syzygium jambos is of possible current conservation concern.     

The recovery of ground ant diversity in secondary Lacandon tropical forests

Ants in tropical forests participate in a wide variety of processes, but human activity can disturb their communities and cause the loss of key species. In this study, we evaluated the effects of human disturbance on the alpha and beta diversity of ant assemblages in a successional gradient of secondary forests growing in abandoned maize fields of the Lacandon region, previously covered by tropical rain forest. Our results show that the alpha diversity of ant species and genera increases with the age of the secondary forests; however, deforestation could cause the loss of certain genera. The turnover of ant species is low along the successional gradient and it is regulated by ecological filters. Secondary forests serve as a refuge for certain ant species and as their successional age increases, they tend to recover the species richness of the mature forest.     

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.     

热带雨林的孢粉垂直分布规律——以海南岛现代孢粉雨为例

热带地区环境变化对研究全球气候变化显得越来越重要,热带地区的古环境记录,特别是孢粉记录是恢复过去气候的重要方法,东亚热带地区在冰期－间冰期的气候影响下,生态环境主要表现为山地植被带的垂直升降,因此,定量恢复热带地区第四纪植被垂直移动的幅度,以及作为古气候的替代性指标进行数量化转换是热带地区孢粉研究的关键,然而,我国热带地区现代孢粉雨和植被的关系研究程度较低,给热带第四纪孢粉古生态的恢复和对比带来困难,本研究较系统地总结了海南岛从低地平原到五指山1860m的垂直植被带表土的孢粉散布规律,为热带地区孢粉古环境的重建提供了新的基础数据。研究结果表明,孢粉组合的变化与垂直植被带紧密相关,孢粉的多样性随海拔升高而降低,其中针叶类随海拔升高而增加,蕨类孢子则相应减少,在低地和低山丘陵,孢粉组合显示出为干扰的影响,如防风雨的主要树种木麻黄（Casuarina),行道树台湾相思（Acacia richii)和人为砍伐后大面积生长的芒箕（Dicranopteris)群落等在一些孢粉谱中特别高,尽管如此,孢粉组合反映的垂直植被带变化仍然是清楚的,海南岛由下至上可划分出5个表土孢粉组合带－低地人类强烈干扰带（＜400m):Mallotus,Casuarina,Pinus,Myrica,Palmae,Poaceaae,Dicranopteris:--低地质陵地带（400－800m):Quercus,Castanopsis,Mallotus,Myrica,Platea,Meliaceae和大量孢子（包括Dicranopteris);--山地下带（800-1200m):Castanopsis,Quercus,Podocarpus,Dacrydium,Cyathea和单缝孢子;－－山地上带（1200-1600m):Dacrydium,Pinus,Altingia,Quercus,Castanopsis;－－山顶带（＞1600m):Pinus,Rhododendron,Dacrydium,Symplocos.     

Bird species richness in vegetation fences and in strips of residual rain forest vegetation at Los Tuxtlas, Mexico

Fragmentation of the lowland tropical rain forest has resulted in loss of animal and plant species and isolation of remaining populations that puts them at risk. At Los Tuxtlas, Mexico, lowland rain forests are particularly diverse in the avian fauna they contain and while most of the forests have been fragmented by human activity, many of the fragments still harbor diverse assemblages of bird species. In these landscapes, linear strips of residual rain forest vegetation along streams as well as linear strips of vegetation fences (live fences) crossing the pastures might provide some connectivity to bird populations existed in forest fragments. We investigated bird species richness and relative abundance in one 6-km long section of live fences (LF) bordering a dirt road and in two 6-km long sections of residual forest vegetation along a river (MR) and one permanent stream (BS). We used point count procedures which resulted in the count of 2984 birds representing 133 species. At the LF site we detected 74% of the species, 72% at the BS site and 57% at the MR site. Only 38% of the species were common among sites. Neotropical migratory birds accounted for 34–41% of the species counted at all sites. While edge and open habitat birds accounted for 6–10% of the species and for 50% of the records at the three vegetation strips, about 90% of the species were forest birds. Distance to forest fragments and degree of disturbance of the vegetation seemed to negatively influence bird species presence at the BS and MR strips. Rarefaction analysis indicated that the LF strip was richer in species than the other two sites, but the occurrence of the three vegetation strips in the landscape seem to favor the presence of many more species. We discuss the value of these vegetation strips to birds as stepping stones in the fragmented landscape.     

Forest Modification Affects Diversity (But Not Dynamics) of Speciose Tropical Pyraloid Moth Communities

We studied temporal and spatial dynamics of extremely diverse moth ensembles (Lepidoptera: Pyraloidea) along a gradient of forest disturbance ranging from undisturbed primary tropical rain forest to different kinds of modified forest and open cultivated land at the margin of Mount Kinabalu National Park (Sabah, East Malaysia). We sampled moths by light trapping during two periods (March‐May and August‐September 1997). We collected a total of 7724 individuals representing 680 species during 78 light‐trapping nights at six study sites. Species diversity (Fisher's α) of ensembles in undisturbed primary forest was distinctly higher than in disturbed or secondary forest. More pyraloid moths were attracted in undisturbed primary forest. Samples from disturbed primary or old‐growth secondary forest were statistically indistinguishable from the undisturbed primary forest ensemble in regard to species composition. Thus, pyraloid ensembles from disturbed forest with tall trees remaining appeared to represent impoverished subsets of the undisturbed primary forest community. The more heavily disturbed sites had a distinct fauna and showed a stronger faunal differentiation among each other. Four species of the genus Eoophyla, in which aquatic larvae feed on algae in fast‐running streams benefited prominently from forest disturbance. Temporal variation of ensembles was remarkably concordant across the disturbance gradient. Relative abundance variation of the commonest species was identical at all sites. Overall, pyraloid moths responded more sensitively to anthropogenic habitat alteration than most other moth taxa studied thus far in tropical regions and allowed for an analysis of diversity patterns at a high temporal resolution.     

砂仁种植对热带雨林植物多样性的影响探讨

通过对各种不同状况的林下种植砂仁的热带雨林片断与同样类型的原始热带雨林的比较研究 ,探讨了砂仁种植对热带雨林植物多样性各个方面的影响。砂仁种植必须大量清除小树、林下幼树、灌木层植物 ,致使种植了砂仁的热带雨林片断的乔木下层及几乎整个的幼树、灌木层遭严重破坏 ,物种和个体大量流失 ,群落结构变得非常不稳定。由于热带雨林的更新主要依赖于其林下层的幼苗库 ,林下层的幼树、苗库被清除或破坏 ,热带雨林就难以自我更新 ,故林下种植砂仁的更大的潜在危害是使得热带雨林不能自我更新。种植了砂仁的热带雨林片断 ,物种和个体数的减少或流失 ,主要是直接的人为清除的结果 ,清除强度大 ,种类和个体减少就多。热带雨林下砂仁种植后 ,那些在原乔木层中占多数的只有 1～ 2个个体的脆弱种类 (种群 )将首先消失     

The intermediate disturbance hypothesis applies to tropical forests, but disturbance contributes little to tree diversity

The intermediate disturbance hypothesis (IDH) predicts local species diversity to be maximal at an intermediate level of disturbance. Developed to explain species maintenance and diversity patterns in species-rich ecosystems such as tropical forests, tests of IDH in tropical forest remain scarce, small-scale and contentious. We use an unprecedented large-scale dataset (2504 one-hectare plots and 331 567 trees) to examine whether IDH explains tree diversity variation within wet, moist and dry tropical forests, and we analyse the underlying mechanism by determining responses within functional species groups. We find that disturbance explains more variation in diversity of dry than wet tropical forests. Pioneer species numbers increase with disturbance, shade-tolerant species decrease and intermediate species are indifferent. While diversity indeed peaks at intermediate disturbance levels little variation is explained outside dry forests, and disturbance is less important for species richness patterns in wet tropical rain forests than previously thought.     

Fruiting patterns of macrofungi in tropical and temperate land use types in Yunnan Province,China

Despite the important contribution of fungi to forest health, biomass turnover and carbon cycling, little is known about the factors that influence fungal phenology. Therefore, in order to further our understanding on how macrofungal fruiting patterns change along a gradient from temperate to tropical climate zones, we investigated the phenological patterns of macrofungal fruiting at five sites along a combined altitudinal and latitudinal gradient in SW China and NW Laos, ranging from temperate to tropical climates. Observations were conducted in the dominant land use types at these study sites: mixed forest (all sites), coniferous forest (temperate sites) and grassland (temperate sites). In total, 2866 specimens were collected, belonging to 791 morpho species, 162 genera, and 71 families. At the site level, the fruiting of ectomycorrhizal (EcMF) and saprotrophic fungi (SapF) occurred at the same time among all land use types. The fruiting season of fungi in the tropical sites began earlier and ended later compared to that of fungi in the temperate sites, which we attribute mainly to the higher temperature and more abundant rainfall of the tropical areas. EcMF taxa richness in temperate forests (both coniferous and mixed forest) showed a distinct peak at the end of the rainy season in August and September, while no significant peak was observed for SapF taxa richness. Neither functional fungal groups showed significant seasonal fluctuations in tropical areas. The temporal turnover of fungal fruiting significantly increased with the shift from tropical to temperate forests along the elevation gradient. In the grasslands, macrofungal abundance was less than 22% of that of corresponding forest sites, and taxa richness was 42% of that of corresponding forest sites. Fungal fruiting showed no significant fluctuations across the rainy season. This work represents a case study carried out over one year, and further measurements will be needed to test if these results hold true in the longer term.     

The effects of disturbance on forest structure and diversity at different altitudes in Garhwal Himalaya

The effects of disturbance on forest structure and diversity along an altitudinal gradient in the temperate, sub-tropical, and tropical regions of Garhwal Himalaya were assessed. Each region was further categorized into undisturbed (UD), mildly disturbed (MD), and highly disturbed (HD) sites on the basis of magnitude of disturbance in these forests. On UD sites of temperate, sub-tropical and tropical regions, Quercus leucotrichophora, Anogeissus latifolia and Holoptelea integrifolia were the dominant tree species respectively. The highest values of tree density (1028 ind*hm-2) and total basal cover at breast height (31.70 m2 *hm-2) were recorded for UD site of temperate region, whereas maximum species diversity (3.128) and equitability (14.09) values were observed for HD site of tropical region. The structure and composition of the forests were greatly affected by the degree of disturbance.     

Diversity,composition, and structure of tropical dry forests in Central America

Tropical dry forests have been reduced to less than 0.1% of their original expanse on the Pacific side of Central America and are considered by some to be the most endangered ecosystem in the lowland tropics. Plots 1000 m² were established in seven tropical dry forests in Costa Rica and Nicaragua in order to compare levels of species richness to other Neotropical dry forest sites and to identify environmental variables associated with species richness and abundance. A total of 204 species and 1484 individuals 2.5 cm were encountered. Santa Rosa National Park was the richest site with the highest family (33), genera (69), and species (75) diversity of all sites. Species richness and forest structure were significantly different between sites. Fabaceae was the dominant tree and shrub family at most sites, but no species was repeatably dominant based on number of stems in all fragments of tropical dry forest. Central American dry forests had similar species richness when compared to other Neotropical forests. There was no correlation between forest cover within reserves, or precipitation and plant species richness. There was a significant correlation between anthropogenic disturbance (intensity and frequency of fire, wood collection, grazing) and total species richness, tree and shrub species richness, and liana abundance. These results suggest controlling levels on anthropogenic disturbance within reserves should be a high priority for resource managers in Central America. Further research in forest fragments which examine individual and a combination of disturbance agents would help clarify the importance of anthropogenic disturbance on species richness and abundance.     

Small logging roads do not restrict movements of forest rats in Bornean logged forests

Selective logging is driving the proliferation of roads throughout tropical rain forests, particularly narrow, unpaved logging roads. However, little is known about the extent of road edge effects or their influence on the movements of tropical understory animal species. Here, we used forest rats to address the following questions: (a) Does the occupancy of rats differ from road edges to forest interior within logged forests? (b) Do roads inhibit the movements of rats within these forests? We established trapping grids along a road edge‐to‐forest interior gradient at four roads and in three control sites within a logged forest in Sabah, Malaysia. To quantify the probability of road crossing, rats were captured, translocated across a road, and then recaptured on subsequent nights. We caught 216 individuals of eight species on 3,024 trap nights. Rat occupancy did not differ across the gradient from road edge to interior, and 48 percent of the 105 translocated individuals crossed the roads and were recaptured. This proportion was not significantly different from that of rats returning in control sites (38% of 60 individuals), suggesting that small roads were not barriers to rat movements within logged forests. Subadults were significantly more likely to return from translocation than adults in both road and control sites. Our results are encouraging for the ecology of small mammal communities in heavily logged forests, because small logging roads do not restrict the movements of rats and therefore are unlikely to create an edge effect or influence habitat selection.     

西双版纳地区六种林型地表蜘蛛多样性比较研究

为探索地表蜘蛛多样性及其变化与森林类型和管理方式的关系, 在西双版纳勐仑自然保护区选择热带季节雨林、石灰山季节雨林和山地常绿阔叶林, 在自然保护区附近选择人工纯林、胶茶群落和橡胶林, 共6种林型, 每种林型选择3块样带, 共设置研究样地18块, 分别于2006年12月上旬（雾凉季）、2007年3月下旬（干热季）和2007年7月上旬（雨季）, 以单位地表面积法收集地表蜘蛛的物种组成和数量数据, 并以蜘蛛种类和数量分布为属性进行典范对应分析（CCA）, 探讨不同类型植被与地表蜘蛛多样性的关系。共采集蜘蛛标本9 849头, 用于统计分析的成熟蜘蛛3 119头, 归属于30科, 其中幽灵蛛科、皿蛛科、球蛛科和小密蛛科是地表蜘蛛的优势类群。各林型科的数量为: 热带季节雨林24科, 石灰山季节雨林22科, 山地常绿阔叶林22科, 人工纯林20科, 胶茶群落21科, 橡胶林19科; 各林型特有科数量: 热带季节雨林2科, 山地常绿阔叶林2科, 橡胶林1科; 而仅在雨林中分布的科4个（占全部30个科的13.3%）, 仅在自然林中分布的科6个（20.0%）, 仅在人工林中分布的科1个（3.3%）。从蜘蛛的数量分布看, 个体密度在热带季节雨林显著高于其他5种林型; 橡胶林多样性指数和丰富度指数显著低于3种自然林, 而均匀度指数的最低值也同样在橡胶林出现。CCA分析和聚类分析的结果表明, 6种林型趋于分成2组, 即: 自然林和人工林; 在自然林中两种次生林的相似程度更高; 人工林中人工纯林（非橡胶林）与胶茶群落的相似程度更高。以上结果表明: （1）森林砍伐后种植人工林措施改变了该地区地表蜘蛛群落的物种分布格局; （2）蜘蛛多样性随着人为干扰程度增加有减少的趋势; （3）减少人为干扰和增加植被群落多样性（橡胶林中种植茶树）对保护和恢复物种多样性有重要意义。     

Temporal and vertical drosophilid (Insecta; Diptera) assemblage fluctuations in a neotropical gallery forest

The drosophilids of a gallery forest in the Brazilian savanna were investigated to identify the temporal and vertical patterns in the community structure of these insects. Twelve monthly collections were performed (December 2007 to November 2008) in three vertical strata of the forest (0, 4 and 8 m heights) using 30 traps baited with fermented banana. The drosophilid assemblage was composed of 61 species (7,623 individuals), experienced temporal fluctuations and was vertically stratified. Both the diversity and abundance of the flies were very low during the dry season, a time when the assemblages were dominated by the exotic species Drosophila simulans, whereas the community showed an increased abundance and richness of neotropical species and showed vertical stratification in the wet season. Rare species were found primarily at the ground level (flies usually associated with neotropical forests) or in the canopy, which harbors species currently associated with open vegetation, little-studied neotropical species and most likely several new species. These changes, which reflect drosophilid adaptations to different environments, involve a shifting of the ecological niches occupied by the flies in the forest over time. This process of change is termed niche construction. Thus, we conclude that this complex and dynamic community structure, which is related to the interaction of several environmental factors associated with different forest environments, contributes to the high diversity of gallery forests in the Brazilian savanna.     

Termite diversity in Neotropical dry forests of Colombia and the potential role of rainfall in structuring termite diversity

Termites are ecosystem engineers that play an important role in the biotransformation and re‐distribution of nutrients in soil. The dry forests are endemic repositories, but at same time, they are most threatened by extensive livestock and crop farming, fires, and climate change. In Colombia, the best‐protected dry forests are located in the north. The termite fauna of dry forests are poorly known. The aim was to identify the termite species occurring in tropical dry forests of the Colombian Caribbean coast in relation to diet and precipitation, temperature, elevation, and soil properties. A total of 32 species in 1,103 occurrences were found. Termitidae accounted for 78% of the species richness with the Anoplotermes‐group, Microcerotermes, and Nasutitermes being the dominant genera. Differences in species composition and abundance were found across sites. These differences may be linked to anthropogenic disturbance and polygyny and polydomy. Strikingly, our highest elevation site (334 m) had the highest species richness much higher than the two lower elevation sites. This implies an inversion of the common elevation‐diversity gradient, also found for termites which can be explained by increasing precipitation with elevation in the dry forest. An analysis of termite species richness at the global scale confirms that termite species richness correlates positively with rainfall. Hence, rainfall seems to positively affect termite diversity. In line, the studied Colombian tropical dry forests had low diversity compared to rain forests. A decline of species‐rich soil‐feeding termites with increasing aridity may explain why the highest termite diversity occurs in humid tropical rain forests. Abstract in Spanish is available with online material.     

论季雨林的水平地带性

季雨林是受制于湿度因子的经度地带性植被类型,它是随着湿度条件的下降由热带雨林向热带疏林过渡的居间类型,而不是受制于温度因子的纬度地带性植被类型,不是随着温度条件的下降由热带雨林向亚热带常绿阔叶林过渡的居间类型。我国南亚热带的榕树群系、黄桐群系,以及热带北缘的青皮群系均不应是季雨林,前二者是典型的南亚热带低地常绿阔叶林或南亚热带雨林,后者则是热带雨林的一分类群。