海南岛热带山地雨林幼苗幼树光合与叶氮、叶磷及比叶面积的关系

以海南岛吊罗山热带山地雨林101个物种的幼苗幼树为试验材料,测定其光合、叶片氮、磷含量及比叶面积;检验其相关关系,并按乔木,乔灌木(小乔木至大灌木)和灌木3个生活型组进行分组检验。研究结果表明,单位叶面积(Aarea)和单位叶重量的光合速率(Amass)均表现出灌木>乔木>乔灌木,方差分析表明,灌木和乔灌木之间Aarea差异显著;灌木和乔木以及灌木和乔灌木之间Amass差异显著(p<0.05)。Aarea与叶氮含量之间的相关性在不同生态型组和所有物种之间均达到极显著水平(p<0.0001);与叶磷之间的相关关系在灌木(p=0.0038),乔灌木(p=0.0002)以及所有物种(p<0.0001)之间达到极显著水平,但是在乔木中未达到显著水平(p>0.05);与SLA之间在灌木(p=0.0006)、乔木(p<0.0001)和所有物种(p<0.0001)之间达到极显著水平,但是在乔灌木中未达到显著水平(p>0.05)。Amass与叶片氮含量、SLA的相关关系在不同生活型组和所有物种中都达到极显著水平(p<0.0001);与叶磷含量之间的相关性在灌木(p=0.0004),乔灌木(p=0.0018)及所有物种(p<0.0001)中极显著,在乔木生活型组中也达显著水平(p=0.0377)。逐步回归表明,与Aarea相比,Amass估计结果更接近于实际测值。由此可见,海南岛热带山地雨林林下幼苗幼树的光合和叶氮、磷含量及SLA之间相关关系与基于成树的研究非常相似,并且A比A更能稳定体现这种相关性。     

海南岛霸王岭热带山地常绿林和热带山顶矮林群落特征

热带山地常绿林和热带山顶矮林均属于热带云雾林.为了揭示其群落结构和物种多样性特征,在海南岛霸王岭热带山地常绿林和热带山顶矮林分别设置8个和10个2,500 m2样方,调查所有DBH≥1cm的乔木、灌木和藤本植株.结果显示:(1)热带山地常绿林幼树(1cm≤DBH＜5 cm)和小树(5cm≤DBH＜ 10 cm)的平均密...     

Forest recovery on abandoned logging roads in a tropical montane rain forest of Hainan Island,China

In this study we report the work in recovering forest stands on Hainan Island in South China; we compared the community composition, structure, and plant functional traits (seed mass and wood density) on three positions of abandoned logging roads: road track (RT), road up-slope edge (UE) and road down-slope edge (DE). The results showed that species richness, stem abundance, basal area, stem size, and canopy height were all lowest on the RT among the three road positions. Species richness and abundance of midstorey and canopy trees were higher on the UE than on the DE. The mean stem size was higher on the DE than the UE, but no significant difference existed in canopy height on the two road edges. The different road positions were characterized by varied species assemblages. Indicator species analysis further indicated that 76.9%, 15.4% and 7.7% of the species showed affinity to UE, DE, and RT, respectively. The RT had more small-seeds but less soft-wood trees than the two road edges. The UE and DE had no significant difference in tree seed class distribution. Compared with the DE, however, the UE had a higher and lower proportion of hard wood in terms of species richness and stem abundance, respectively. Our results indicated that the composition and structure of stands on the abandoned logging roads had significantly changed in comparison with the stands around it.     

海南霸王岭山地原始林与伐后林中木质藤本对支持木的选择

通过对海南霸王岭热带山地原始林与伐后林中树木及其攀附木质藤本的调查,研究原始林与伐后林中木质藤本对支持木的选择性。结果表明:1)6科优势树木中附藤率最高的是野牡丹科(Melastomataceae),附藤率最低的科,原始林中是山矾科(Symplocaceae),伐后林中是茜草科(Rubiaceae)。2)原始林中,谷木(Memecylon ligustrifolium)与线枝蒲桃(Syzygiumaraiocladum)的附藤比率和每木藤本数均高于样地平均水平;三角瓣花(Prismatomeris tetrandra)和龟背灰木(Symplocosandenophylla)的附藤比率均低于样地平均水平,而每木藤本数与样地平均水平之间没有显著差异。伐后林中,谷木的附藤比率和每木藤本数高于样地平均水平;九节(Psychotria rubra)的附藤比率和每木藤本数低于样地平均水平。3)杜仲藤(Parabariummicranthum)的主要支持木是谷木,夜花藤(Hypserpa nitida)的主要支持木是线枝蒲桃。研究表明,木质藤本对支持木在科和种水平上都具有选择性,因此木质藤本会对树木造成不对称影响,进而影响森林的结构和动态。     

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。     

海南岛热带山地雨林天然次生林的功能群划分

热带林极高的物种丰富度使许多生态分析非常困难,把功能相似的物种划分为不同功能群,将为热带林的生态研究提供新的途径。以物种的7个功能特性因子(生长型、分布的海拔高度、分布的林型、木材密度、喜光性、演替地位和寿命)和9个林分结构因子(相对生物量、相对胸高断面积、相对树高、相对密度、相对频度、相对冠幅、相对更新数、相对死亡数和相对萌生数)为基础,应用数量化分析的方法,对海南岛典型的热带山地雨林天然次生林群落进行了功能群的划分。结果表明:(1)应用CCA分析林分结构因子时,可将山地雨林天然次生林的物种划分为6类功能群,它们的相对生物量、相对密度、相对频度、相对更新数、相对萌生数和相对死亡数等,随胸径和高度的增加而呈现有规律的变化;(2)应用CCA分析物种功能特性因子时,可将山地雨林天然次生林的物种划分为5类功能群,它们的功能特性都随演替过程而呈现有规律的变化;(3)在综合考虑两个不同角度CCA分析的基础上,最后将热带山地雨林天然次生林的物种共划分为11类功能群,它们能充分体现物种随胸径和高度结构的变化特点及其在演替过程中所处的阶段;(4)演替初期的灌木类功能群与各不同演替时期的乔木功能群共同分布于的中下层,但其大多处于死亡状态;(5)演替初期与演替中后期的乔木功能群则共同组成的主层林,但其死亡数量也较高。可见,海南岛热带山地雨林天然次生林目前正处不同功能群的激烈竞争阶段。     

Seasonal changes in stem diameter and leaf development in a tropical montane forest

Abstract. Seasonal patterns of stem diameter changes in evergreen and deciduous species of a tropical montane forest in the Central Himalayas (300–2250 m a.s.l.) were investigated in relation to leaf development. Ca. 75 % of the annual rainfall in this region occurs in a short period, from mid-June to mid-September and the remaining months are dry. It was assumed that changes in stem diameter are correlated with changes in water stress. Each evergreen species could be characterized by leaf longevity of about one year; each species showed pronounced summer leaf drop and simultaneous new leaf formation. Winter stem shrinkage was more pronounced in deciduous species than in evergreen ones. The deciduous species also showed a greater proportional loss of leaf mass (before abscission) than the evergreen species. Winter leaf fall in deciduous species was related to the pronounced stem shrinkage. The leaf fall enabled these species to control further water loss. Being more resistant to desiccation, the evergreen species retained their leaves throughout the winter but showed gradual loss of leaf mass, presumably in order to control water loss. In all species, leaf expansion was completed before the onset of the rainy season, when water stress was high. This strategy has definite advantages in a climate with a monsoon pattern of rainfall. Evergreen species, showing pronounced leaf drop in summer, have advantages over deciduous species; hence their preponderance in the region.     

海南五指山热带山地雨林植物物种多样性研究

王指山热带山地雨林的物种种类十分丰富,在１ｈｍ＾２样地中共出现５４个科,１００个属的乔木树种１７７种,１３３７个个体。区系地理分析表明属的分布区类型以热带分布型成分占优,为８９．０％,充分体现了五指山山地雨林的热带性质。多样性指数分析结果为：样地１Ｍａｒｇａｌｅｆ指数１７．８２２,Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ指数５．６２１,均匀度０．８２３,Ｓｉｍｐｓｏｎ指数０．０５０,均匀度６．７７５,表明五指     

海南热带山地雨林幼苗幼树的光合能力与水分利用效率

应用Li-6400光合测定系统研究了海南岛热带山地雨林林内幼苗、幼树的最大光合能力及其水分利用效率.结果表明:150个树种中,大戟科中平树的最大光合速率(Pmax)和山毛榉科竹叶栎的水分利用效率(WUE)最高,分别为13.27μmol.m-2.s-1和5.99mmol.mol-1;桃金娘科柬埔寨子楝树的Pmax和大戟科山乌桕的WUE最低,分别为1.35μmol.m-2.s-1和2.4mmol.mol-1.其中,Pmax以桑科的平均值最高,桃金娘科最低;WUE以山矾科的平均值最高,桑科最低;但各科间的差异均不显著(P>0.05).乔木和灌木之间的Pmax和WUE也无显著差异(P>0.05).Pmax随着科分布区的扩大而增大,为宽分布科>中分布科>窄分布科,且差异显著(P<0.05);WUE无显著差异.在种的层次上,随着物种分布区的扩大,植物Pmax逐渐增大,为热带亚热带温带种>热带亚热带种>热带种>海南特有种.而WUE则相反,为海南特有种>热带亚热带种>热带种>热带亚热带温带种.     

海南尖峰岭热带山地雨林物种多样性空间分布格局的尺度效应

物种多样性的空间分布格局和维持机制是群落生态学的基本问题。为了探讨海南尖峰岭地区物种多样性空间分布格局的尺度效应, 以海南尖峰岭热带山地雨林60 hm²样地为研究对象, 分析了物种丰富度、物种多度、Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数随6个空间取样尺度(5 m × 5 m、10 m × 10 m、20 m × 20 m、40 m × 40 m、100 m ×100 m、200 m × 200 m)的变化。结果表明: 相比Simpson指数和Pielou均匀度指数, 物种丰富度、多度以及Shannon-Wiener指数具有更为明显的空间尺度效应; 物种丰富度的方差随取样尺度增加呈现单峰分布特征, 并且在20 m × 20 m尺度上达到最大值, 而物种多度的方差随取样尺度的增加而增大; 物种丰富度和多度的正相关性随着取样尺度的增加逐渐减小甚至消失, 这可能与随取样尺度增加生境异质性增加有关; 取样尺度对3个物种多样性指数空间分布的影响可能与研究区域内稀有种的组成有关。     

Polyphenols in litter from tropical montane forests across a wide range in soil fertility

In nutrient-poor ecosystems high polyphenol concentrations in plant litter have been proposed to influence soil nutrient availability in benefit of the plants. We addressed the question whether litter polyphenol concentrations vary across a soil chronosequence of almost identical geology, climate and plant species composition, but of a wide range in nitrogen (N) and phosphorus (P) availability in the Hawaiian Islands. Concentrations of total phenolics (TPh) and proanthocyanidins (PA) in leaf litter of the dominant tree species Metrosideros polymorpha were higher at the oldest, P-limited site compared to the youngest, N-limited site, with intermediate values at the two relatively fertile sites co-limited by N and P. Polyphenol concentrations in fine root litter differed considerably from those observed in leaf litter and varied differently across the soil age gradient. Long-term fertilization did not significantly alter polyphenol concentrations in Metrosideros litter at either site. Moreover, green leaves and leaf litter of Metrosideros showed similar relative differences among sites when compared between natural populations and plants from the same populations but grown in a common garden. These results suggest that polyphenol concentrations inherently vary among populations of the dominant tree species in Hawaiian montane forests possibly indicating an adaptation to ecosystem properties such as substrate age related differences in soil fertility. The combined above- and below-ground input rate of TPh ranged from 62.4 to 170.8 g/m²/yr and was significantly higher at the P-limited than at the N-limited site. Root-derived polyphenols contributed a much higher absolute and relative amount of phenolic input at the N-limited than at the P-limited site. The differences in amount, quality, and pathways of input might suggest specific interactions with soil processes and nutrient cycling among the Hawaiian rainforests studied here.     

Scale-dependent spatial patterns of species diversity in the tropical montane rain forest in Jianfengling,Hainan Island,China

Aims Spatial distribution patterns and formation mechanisms of species diversity are fundamental issues in community ecology. The objectives of this study are to assess the species diversity patterns at the different spatial scales in Jianfengling, Hainan Island, China.
Methods Based on the dataset from the 60 hm² plot in the tropical montane rain forest in Jianfengling, Hainan Island, the spatial distribution patterns of species richness, species abundance, Shannon-Wiener, Simpson and Pielou’s evenness indices were analyzed at six spatial scales, including 5 m × 5 m, 10 m × 10 m, 20 m × 20 m, 40 m × 40 m, 100 m × 100 m, and 200 m × 200 m, respectively.Important findings
Results showed that spatial distribution patterns of species richness, species abundance and Shannon-Wiener index were much more obviously changed with the spatial scales than Simpson and Pielou’s evenness indices. Change of variance of the species richness with the increase of spatial scales was unimodal, which had the maximum value at the 20 m × 20 m scale. Variance of the species abundance showed a linear relationship with the increase of spatial scales. The positive relationship between species richness and abundance gradually decreased and even disappeared with the increase of sampling scales, which may be correlated with the increase of habitat heterogeneity. The effects of spatial scales on Shannon-Wiener, Simpson, and Pielou’s evenness indices may be also correlated with the composition of rare species in the plot.     

Photosynthetic parameters,dark respiration and leaf traits in the canopy of a Peruvian tropical montane cloud forest

Few data are available describing the photosynthetic parameters of the leaves of tropical montane cloud forests (TMCF). Here, we present a study of photosynthetic leaf traits (V _cmax and J _max), foliar dark respiration (R _d), foliar nitrogen (N) and phosphorus (P), and leaf mass per area (LMA) throughout the canopy for five different TMCF species at 3025 m a.s.l. in Andean Peru. All leaf traits showed a significant relationship with canopy height when expressed on an area basis, and V _cmax-area and J _max-area almost halved when descending through the TMCF canopy. When corrected to a common temperature, average V _cmax and J _max on a leaf area basis were similar to lowland tropical values, but lower when expressed on a mass basis, because of the higher TMCF LMA values. By contrast, R _d on an area basis was higher than found in tropical lowland forests at a common temperature, and similar to lowland forests on a mass basis. The TMCF J _max–V _cmax relationship was steeper than in other tropical biomes, and we propose that this can be explained by either the light conditions or the relatively low VPD in the studied TMCF. Furthermore, V _cmax had a significant—though relatively weak and shallow—relationship with N on an area basis, but not with P, which is consistent with the general hypothesis that TMCFs are N rather than P limited. Finally, the observed V _cmax–N relationship (i.e., maximum photosynthetic nitrogen use efficiency) was distinctly different from those in tropical and temperate regions, probably because the TMCF leaves compensate for reduced Rubisco activity in cool environments.     

海南岛热带森林景观类型多样性

依据景观生态学原理,按地貌、气候、土壤、植被和土地利用方式的分异,以带、域、省、区、类型为5个基本单位及亚、组等为辅助单位,组建海南岛热带森林景观类型分类体系。把海南岛热带森林景观作为省级单位,它隶属于全球热带林景观带、亚洲（东方）热带林景观域、中国热带林景观亚域,其下划分为东部潮湿森林景观、西部半干旱森林景观、中南部山地森林景观、热带常绿针叶林景观、热带竹林景观和热带人工林景观6个森林景观区;以热带低地沟谷热带雨林为代表的11个森林景观亚区;以热带低地沟谷龙脑香森林景观为代表的26个森林景观类型组;以热带低地沟谷青皮林为代表的54个森林景观类型。海南岛热带森林景观类型分类体系较全面地表达了海南岛热带森林景观类型多样性。     

Foliage dynamics, leaf traits, and growth of coexisting evergreen and deciduous trees in a tropical montane forest in Ethiopia

Foliage dynamics of three functional tree types representing major components of the tropical montane evergreen forest in southern part of Central Ethiopia were compared. The species were Podocarpus falcatus (evergreen gymnosperm), Prunus africana (evergreen broadleaf), and Croton macrostachyus (facultative deciduous). The hypothesis examined is that in such tropical trees, endogenous control of foliage dynamics by the leaf life-spans (LLS) is largely dominant over external signals. Crown foliage turnover, leafiness of twigs, LLS, photosynthetic performance, respiration rate, specific leaf area, and relative growth rates of the stems were investigated. Foliage dynamics and leafiness of the twigs were monitored over 2?years while leaf traits were followed over 3?months. The degree of inter and intra-individual synchronization of foliage phenophases was examined to get an estimate of the contributions of endogenous and external signals to the dynamics of the foliages. Autoregression analysis indicated significant influence of the moisture regime on leaf sprouting of Croton and Podocarpus. During pronounced dry periods, new leaves were not developed. Analysis of phenological data using circular statistics revealed that in spite of strong inter-individual synchronization of leaf flush and fall (Podocarpus and Croton), the dynamics of individual parts of the crowns were less synchronized. LLS was independent of climate factors and it had substantial contribution to the control of foliage turnover. Moreover, examination of ecophysiological traits of developing leaves of the studied functional types showed differing patterns with LLS corroborating the ecophysiological characteristics. Although overlaid by fungal infestation, both the foliage and ecophysiological properties of Prunus resemble that of Podocarpus but the former exhibited a shorter LLS and slightly higher metabolic rates. Nevertheless, all species reacted positively to high moisture with respect to stem growth. In spite of largely differing weather conditions of the 2?years, direct competitive advantage of one of the species over the others could not be detected.     

Leaf demography and leaf traits of temperate-deciduous and tropical evergreen-broadleaved trees in a Mexican montane cloud forest

The spatial variation in epilithic lichen community structure was investigated as part of a larger study of the vegetation and ecology of the tall limestone cliffs within the Niagara Escarpment Biosphere Reserve in southern Ontario, Canada. The cover of all lichen taxa was visually estimated for a total of 199 samples taken from the top, middle, or bottom of the cliff face at five sites. Twelve environmental variables were also measured. Twenty-seven lichen taxa were identified on the samples. Multivariate ordinations of species composition (DCA, CCA, PCCA) revealed variation in community structure on multiple scales, but no groupings of sites that would have suggested the presence of several distinct species assemblages. A gradient in species composition from north to south, most clearly reflected in the decreasing cover of foliose and fruticose species, may reflect a gradient in human disturbance. There was also intermediate-scale patchiness in species composition in a horizontal plane across cliffs, but despite earlier claims made in the literature, no evidence of vertical zonation of the lichens on cliffs was found. Species composition also responded to small-scale factors possibly related to exposure, light, or moisture. Unlike community composition, the total cover of all lichens was homogeneous over large spatial scales and varied only on a small scale, illustrating that scale as well as resolution of a study may influence the ecological patterns seen. More than half of the species found on the Niagara Escarpment are rare on rock substrates elsewhere in southern Ontario, and two are new for North America (Candelariella heidelbergensis (Nyl.) Poelt and Lecanora perpruinosa Fröberg). The result that cliffs support a distinct flora containing many rare species suggests that they are a reservoir for biodiversity not just for vascular plants, but also for lichens.     

海南尖峰岭热带山地雨林60ha动态监测样地群落结构特征

热带山地雨林是海南岛最占优势的植被类型,以往对热带山地雨林的研究通常基于小尺度,缺乏大尺度上的长期固定样地监测。作者基于海南岛尖峰岭地区60 ha(1,000 m×600 m)植被动态监测大样地,详细描述了该样地所属典型热带山地雨林的群落结构特征,以期为更深入地揭示我国热带雨林地区的物种多样性及其维持机制提供背景资料。尖峰岭大样地20 m×20 m样方水平上海拔和坡度分别在866.3–1,016.7 m和1.7°–49.3°间变化。大样地内共记录到439,676株存活的胸径≥1.0 cm的乔灌木植株,除61个植株未确定种名外,其他分属于62科155属290种。单位面积植株密度为0.7328株/m2(含萌条和分枝),20 m×20 m尺度上单位面积物种数量为32–120种,平均80种。植物属区系成分以热带性质为主,共有136属,占总属数的88.3%;另有鼠李科鼠李属(Rhamnus)为世界分布,木兰科拟单性木兰属(Parakmeria)为中国特有分布。按物种重要值排序,大样地内最具优势(重要值大于2.0)的6个种分别为:大叶蒲葵(Livistona saribus)、白颜树(Gironniera subaequalis)、厚壳桂(Cryptocarya chinensis)、油丹(Alseodaphne hainanensis)、四蕊三角瓣花(Prismatomeris tetrandra)和海南韶子(Nephelium topengii)。优势科为樟科、壳斗科、茜草科和棕榈科,重要值均超过了5.0。取样面积达到7.5 ha或取样数量达到2万株时,计数到的物种数量达到261种,占总物种数量的90.0%。大样地内稀有种和偶见种各占所有物种的20.7%和37.6%。样地内所有个体平均胸径5.22 cm,植株径级分布呈明显的倒"J"形。本文为后续尖峰岭大样地的研究提供了背景资料,尖峰岭大样地的建立也为热带地区生物多样性长期变化监测提供了一个基础平台。     

Variations in dung beetle assemblages across a gradient of hunting in a tropical forest

Populations of large mammals are severely depleted by hunting in tropical forests, with direct effects on plant regeneration. But indirect consequences on commensal taxa depending on them for food resources, like coprophagous beetles, are less documented. Cascading effects of species loss across Scarabaeinae are expected, with likely significant negative implications for ecosystem functions. We examined dung beetle assemblages using pitfall traps at three rain forest sites in French Guiana ranging from intact mammalian fauna (Nouragues) to moderate (Kaw) and heavy (Matoury) defaunation. The site with the most depauperate mammalian fauna showed significantly lower dung beetle species richness than the two other two sites, which were not different from each other. Mean abundance and biomass per trap were not different across sites whereas community composition strongly differed among sites. A positive correlation was observed between body size and the individual contribution to dissimilarity between Nouragues and Kaw. The species contributing the most to dissimilarity were large. By contrast, one medium-sized species, dominant in Matoury, contributed the most to dissimilarity between Matoury and other sites. Diurnal genera of large tunnellers showed a higher diversity and abundance in Nouragues compared to other sites, whereas a nocturnal genus showed no differences. Large rollers were more abundant in Kaw compared to other sites. None of the groups of small beetles but one were affected by defaunation. Our results suggest that loss of large mammal populations affects dung beetle assemblage structure and causes decreasing abundance or disappearance of large tunnellers species that have a major impact on several dung beetle-mediated ecological processes.     

Trait-based community assembly of understory palms along a soil nutrient gradient in a lower montane tropical forest

Two opposing niche processes have been shown to shape the relationship between ecological traits and species distribution patterns: habitat filtering and competitive exclusion. Habitat filtering is expected to select for similar traits among coexisting species that share similar habitat conditions, whereas competitive exclusion is expected to limit the ecological similarity of coexisting species leading to trait differentiation. Here, we explore how functional traits vary among 19 understory palm species that differ in their distribution across a gradient of soil resource availability in lower montane forest in western Panama. We found evidence that habitat filtering influences species distribution patterns and shifts community-wide and intraspecific trait values. Differences in trait values among sites were more strongly related to soil nutrient availability than to variation in light or rainfall. Soil nutrient availability explained a significant amount of variation in site mean trait values for 4 of 15 functional traits. Site mean values of leaf nitrogen and phosphorus increased 37 and 64%, respectively, leaf carbon:nitrogen decreased 38%, and specific leaf area increased 29% with increasing soil nutrient availability. For Geonoma cuneata, the only species occurring at all sites, leaf phosphorus increased 34% and nitrogen:phosphorus decreased 42% with increasing soil nutrients. In addition to among-site variation, most morphological and leaf nutrient traits differed among coexisting species within sites, suggesting these traits may be important for niche differentiation. Hence, a combination of habitat filtering due to turnover in species composition and intraspecific variation along a soil nutrient gradient and site-specific niche differentiation among co-occurring species influences understory palm community structure in this lower montane forest.