Rainforest Species Research Articles

A simple competition model can predict rainforest tree diversity, species abundance and ecosystem functions

Abstract The coexistence of tree species in tropical forests has remained challenging to explain, characterise and predict with simple theoretical models. To address this phenomenon researchers have focused on processes and factors omitted in simple competition models. Meantime, theoretical considerations of simple models have sought out conditions for stable coexistence of many species. Here we show that a simple competition model parameterised by repeated forest tree inventory data can estimate the stable coexistence of numerous tree species and predict their biomass abundance and productivity in equilibrium communities. We apply a simple Lotka–Volterra competition model to describe species aboveground biomass, and employ leaf biomass as a proxy for exploitative competition among species. In such systems a globally stable multispecies equilibrium arises when, for every species, susceptibility of biomass growth to conspecific (same species) leaf biomass exceeds that to heterospecific leaf biomass. We applied this approach to tree species in the Pasoh 50‐ha plot of Malaysian lowland mixed dipterocarp forest. We parameterised species aboveground biomass productivity by tree growth, by recruitment, and losses from tree mortality. Biomass gains minus losses yields the biomass growth of each species population. Using variation in leaf biomass among quadrat subplots, we estimated the susceptibility of productivity by tree growth to conspecific and heterospecific leaf biomass. Our model analyses with plot census data predicted the stable coexistence of 351 of the 487 tree species assessed. Susceptibility to conspecific versus heterospecific leaf biomass was greater across all species (median: 95 times). The implied effect of conspecific competition appears to reflect ontogeny, that is declining relative tree growth with tree size. The equilibrium biomasses for predicted persistent species were broadly similar to observations. Removal of species indicates that ecosystem biomass and productivity at equilibrium increases asymptotically with species richness. Synthesis. Our analyses with simple model provide a range of non‐trivial insights into tree species coexistence, community structure and ecosystem stability within a species‐rich rainforest. The insights available from such simple models provide references for a reassessment of the insights from more complex models and approaches.

Effect of Storage on Seed Vigour and Germinability of Selected Rainforest Species from Sri Lanka for Seed-Based Forest Restoration

Effect of Storage on Seed Vigour and Germinability of Selected Rainforest Species from Sri Lanka for Seed-Based Forest Restoration

Bark water affects the isotopic composition of xylem water in tropical rainforest trees

The movement of water between xylem and inner bark (phloem and associated tissues), mostly driven by water potential differences, forms a key part of the diel transpiration cycle. It is not known how the use of water stored in bark at the diel transpiration cycle may influence the isotopic composition of xylem water. Understanding these possible effects is a major challenge for the identification of tree water sources and the interpretation of water use patterns using isotopes. Here, we examined the variation in the isotopic composition of water in inner bark and xylem at the diel scale and assessed how this varied in relation to traits and water use strategies on nine tree species in a tropical rainforest at the end of the dry season. We measured δ2H and δ18O in bark and xylem at two shallow depths: ‘outer xylem’ and ‘inner xylem’ (up to ~0.5 cm and ~ 1 cm from inner bark, respectively) collected at predawn, morning and midday. Considering all species together, the average isotopic composition of water in bark and outer xylem was similar at predawn and midday, suggesting water exchange between these tissues was reflected at these times, but differed significantly in the morning during increased transpiration. Results suggest that bark-xylem water exchange throughout the diel transpiration cycle affects the isotopic composition of xylem water in tropical rainforest trees. Furthermore, variations in δ2H and δ18O between xylem and bark were more pronounced in a deep-rooted, more isohydric species with dense wood than in a shallow-rooted, more anisohydric species with low wood density. This may suggest differences related to traits and hydraulic strategies in the reliance of bark-stored water across the diel cycle to buffer changes in xylem water potential. We discuss implications for interpreting tropical tree water sources in relation to water use strategies.

Leaf warming in the canopy of mature tropical trees reduced photosynthesis due to downregulation of photosynthetic capacity and reduced stomatal conductance.

Tropical forests play a large role in the global carbon cycle by annually absorbing 30% of our annual carbon emissions. However, these forests have evolved under relatively stable temperature conditions and may be sensitive to current climate warming. Few experiments have investigated the effects of warming on large, mature trees to better understand how higher temperatures affect these forests in situ. We targeted four tree species (Endiandra microneura, Castanospermum australe, Cleistanthus myrianthus and Myristica globosa) of the Australian tropical rainforest and warmed leaves in the canopy by 4°C for 8 months. We measured temperature response curves of photosynthesis and respiration, and determined the critical temperatures for chloroplast function based on Chl fluorescence. Both stomatal conductance and photosynthesis were strongly reduced by 48 and 35%, respectively, with warming. While reduced stomatal conductance was likely in response to higher vapour pressure deficit, the biochemistry of photosynthesis responded to higher temperatures via reduced Vcmax25 (-28%) and Jmax25 (-29%). There was no shift of the Topt of photosynthesis. Concurrently, respiration rates at a common temperature did not change in response to warming, suggesting limited respiratory thermal acclimation. This combination of physiological responses to leaf warming in mature tropical trees may suggest a reduced carbon sink with future warming in tropical forests.

Water sources selected for immature development of some African rainforest dwelling mosquitoes under different landscapes in Cameroon.

Little is known about the behaviors of African equatorial rain forest mosquito species and their potential role as sylvatic and bridge-vectors of various pathogens of animal and public health. In 2016 and 2017, the diversity and sources of water supporting immature development of mosquitoes in Talangaye Rainforest (South West Cameroon) before, during and after deforestation were investigated. Mosquito eggs, larvae and pupae were collected from 12 natural, seminatural, and artificial water sources and reared to adults. A total of 595 adult mosquitoes belonging to seven genera and at least 43 species were identified. Culex was the most abundant (56.3%) and was encountered in the majority in bamboo pots. Aedes and Uranotaenia species were mostly found in rock pools, while Anopheles and Hodgesia species solely prefer stream pools. In terms of mosquito abundance, rock pools were the most productive (29.91%) followed by bamboo pots (24.7%). Natural sites such as rock pools, tree holes, and stream pools recorded a greater number of species (S = 21, 14 and 12 respectively). During the rainy season, rock pools (46.23%) and bamboo pots (18.7%) were the most productive water bodies, while in the dry season, bamboo pots (35.71%) and stream pools (35.71%) harbored the most mosquitoes. The disturbed and pristine-like habitats had the greatest number of mosquitoes and breeding sites compared to palm plantation. This study provides some useful data on water sources used for immature development of forest mosquito species in Southwest Cameroon and how some species might adapt to changing landscapes, especially due to deforestation.

Framing a Biobanking Response to Myrtle Rust in Western Australia.

Myrtle rust is a plant disease caused through infection by the fungus Austropuccinia psidii and was first detected in Australia in 2010. The disease has spread through New South Wales, Victoria, Queensland, the Northern Territory, and Tasmania. In this short timeframe, myrtle rust has had a devastating impact on many native species in the family Myrtaceae, including several rainforest species that are now at risk of extinction. In 2022, myrtle rust was first detected in the northern part of Western Australia (WA)-the largest state in Australia. WA is home to ca. 2000 Myrtaceae taxa (ca. 60% of Australia's Myrtaceae diversity), many of which form the dominant component of the vegetation across several ecosystems (e.g., Eucalyptus, Corymbia, Melaleuca, Agonis, Verticordia etc.). While modelling suggests that the environmental conditions in WA's north are less conducive to myrtle rust in comparison to the wet, temperate rainforests of the east coast, WA's temperate, Myrtaceae-rich south coast may be climatically suitable. Coupled with the sheer abundance of Myrtaceae species in WA, their high degree of endemism, high proportion of threatened species, and little available information on their susceptibility to myrtle rust, a pre-emptive strategy to conserve germplasm of at-risk species is warranted. This paper highlights the role of ex situ germplasm conservation in responding to biosecurity threats such as myrtle rust. With early intervention critical to sourcing healthy and genetically diverse germplasm, we present a prioritized list of genera and species of Myrtaceae in WA to inform strategic, coordinated, and timely ex situ conservation actions, along with case studies to illustrate the complementary approaches of seed banking, cryobiotechnology, and tissue culture necessary to conserve germplasm of WA's myrtaceous flora.

Adaptive trade-offs between vertebrate defence and insect predation drive Amazonian ant venom evolution.

Stinging ants have diversified into various ecological niches, and selective pressures may have contributed to shape the composition of their venom. To explore the drivers underlying venom variation in ants, we sampled 15 South American rainforest species and recorded a range of traits, including ecology, morphology and venom bioactivities. Principal component analysis of both morphological and venom bioactivity traits reveals that stinging ants display two functional strategies where species have evolved towards either an exclusively offensive venom or a multi-functional venom. Additionally, phylogenetic comparative analysis indicates that venom function (predatory, defensive or both) and mandible morphology correlate with venom bioactivity and volume. Further analysis of the venom biochemistry of the 15 species revealed switches between cytotoxic and neurotoxic venom compositions among species. Our study supports an evolutionary trade-off between the ability of venom to deter vertebrate predators and to paralyse insect prey which are correlated with different venom compositions and life-history strategies among Formicidae.

Soil total phosphorus mediate the assembly processes of rhizosphere microbial communities of ficus species in a tropical rainforest

Revealing the assembly processes of plant rhizosphere microbial communities and the underlying influencing factors is essential for understanding the biodiversity and function of forest ecosystem. However, it remains unclear how deterministic and stochastic processes shape community structure and their relative importance in phosphorus-limited tropical environments. Here, we investigated the diversity, composition, and assembly processes of rhizosphere microbial communities of Ficus species in the Xishuangbanna region of southwest China, using methods such as high-throughput sequencing, variance partitioning analysis and null model analysis. We found that the community assembly processes of bacteria and fungi were primarily dominated by deterministic processes, with the fungal group being more deterministic than the bacteria group. Soil total phosphorus (TP) was the primary determinant of the composition and assembly of the rhizosphere microbial community, explaining 12.58% and 21.35% of the compositional variation in bacterial and fungal communities, respectively, and accounting for 14% of the microbial community assembly, but has a minor impact on their alpha diversity. This study highlights the distinct environmental driving factors of community composition and community assembly. The exposed positive relationship between soil TP and microbial deterministic process has inspiration for link of microbial community functions to soil function and sustainable forest management.

Relationships between abiotic factors, foliage chemistry and herbivory in a tropical montane ecosystem

Herbivore–plant interactions are fundamental processes shaping ecosystems, yet their study is challenged by their complex connections within broader ecosystem processes, requiring a nuanced understanding of ecosystem dynamics. This study investigated the relationship between nutrient availability and insect herbivory in the Australian Wet Tropics. Our objectives were threefold. Firstly, to understand what factors influence nutrient availability for plants and herbivores across the landscape; secondly, to investigate how trees of different species respond to nutrient availability; and thirdly, to unravel how the relationships between resources and plant chemistry affect herbivory. We established a network of 25 study sites covering important abiotic gradients, including temperature, precipitation, and geology. Employing a hierarchical modelling approach, we assessed the influence of climate and geology on resource availability for plants, primarily in the form of soil nutrients. Then, we explored the influence of the above factors on the interaction between herbivory and foliage chemistry across three widespread rainforest tree species, comparing how these relationships emerged across genera. Our findings suggest an overarching influence of climate and geology over soil chemistry, foliar nitrogen, and insect herbivory, both directly and indirectly. However, individual constituents of soil fertility showed equivocal influences on spatial patterns of foliage chemistry once site geological origin was accounted for, suggesting a questionable relationship between individual soil nutrients and foliar composition. We have demonstrated that herbivore–plant interactions are complex dynamics regulated by an intricate web of relationships spanning different biogeochemical processes. While our results provide some support to the notion that herbivory is affected by resource availability, different species growing under the same conditions can show differing responses to the same resources, highlighting the importance of identifying specific limiting factors rather than simpler proxies of resource availability.

Aiouea ombrophila (Lauraceae), a new large tree from the wet mountains of the Atlantic Rainforest, Brazil

The study of tree species in the Brazilian Atlantic Rainforest continues to reveal new discoveries. Herbarium collections often harbor specimens that do not fit into known taxa. During our research, we encountered an unidentified Lauraceae specimen, prompting us to conduct fieldwork in the forest to investigate further. This study describes Aiouea ombrophila Brotto & Völtz, a large tree from the rainiest parts of the mountainous slopes of Minas Gerais, Rio de Janeiro and São Paulo states, Brazil, at elevations between 950 and 2000 m. We provide a comprehensive description of the new species, including illustrations, a distribution map, an extinction risk assessment, and a comparative table distinguishing it from other species.

Display court ecology in male Albert’s Lyrebirds

ABSTRACT Display courts are fundamental to the sexual displays of many species of bird; however, the ecology of display courts is poorly understood, representing an important gap in our understanding of the function and evolution of complex animal displays. Here, we describe the biophysical attributes (‘ecology’) of the display courts of male Albert’s Lyrebirds, a ground-dwelling rainforest species that performs a spectacular song and dance display on set courts, known as ‘display platforms’, that are composed of vines or fallen branches. Males rhythmically move these vegetative structures while singing, forming a unique ‘stage shaking’ component of their sexual display. We investigated whether display platforms differed from random locations within a male’s territory in terms of the number of vines or other vegetative structures, area of ground clearing, vegetation density, and canopy cover measurements. We primarily found that platforms had a larger number of vines or other vegetative structures. Platforms also tended to be in areas with more canopy openings. We suggest that platform features amplify the movement of the dancing male, and that male Albert’s Lyrebirds choose platforms in locations that increase their conspicuousness to female receivers.

Traits associated with the conservation gradient are the strongest predictors of early‐stage fine root decomposition rates

Abstract Fine root traits span two independent axes of variation, the conservation and collaboration axes, which define the root economic space (RES). However, whether early‐stage fine root decomposition rates (quantified as proportion mass loss, i.e. pml) are more strongly related to collaboration or conservation traits remains unclear. We studied 63 tree species in New Zealand's temperate rain forest. We determined the phylogenetic signal in pml and fine root traits, conducted phylogenetic principal component analysis and used phylogenetic generalized least squares to determine which traits are most strongly related to pml. Root decomposition exhibited a high phylogenetic signal and was more strongly related to the conservation than the collaboration axis. Root tissue density (RTD) was negatively correlated and root nitrogen (RN) was positively correlated with pml. Root diameter was positively yet weakly correlated with pml, but specific root length was uncorrelated with pml. The lignin‐to‐N ratio and root cellulose were the strongest predictors of pml. Synthesis: Early‐stage fine root decomposition is most strongly driven by tissue quality traits, such as root nitrogen, tissue density and lignin‐to‐N ratio, which all align with the conservation axis of the root economics space. However, root diameter plays a weak yet undeniable role in early‐stage fine root decomposition. Some thick‐rooted species decomposed faster, possibly due to the higher quality cortical tissue. Thin‐rooted species decomposed slower, possibly because of their higher cellulose concentration that maintains the structural integrity of small diameter roots. Relationships between decomposition and other traits that align with the collaboration gradient deserve further study across the phylogeny of vascular plants.

New records of Gemeneta opilionoides (Orthoptera, Catantopinae) in the world's second largest rainforest.

Gemeneta opilionoides (Bolívar 1905) is a rare grasshopperpresently known fromthree localities, Biafra (in Equatorial Guinea), Makak, and Ngutadjap (in Cameroon). Few data exist on the biology and ecology of this species in the central Africa rainforests, while its natural habitat is being rapidly destroyed by deforestation. It has been recently found at two new localities, Ngoyla in Cameroon, and Bioko Island in Equatorial Guinea. From 2019 to 2023 some specimens of the species were recorded and collected at these two localities. This study increased the number of known G. opilionoides localities to five: Biafra, Makak, Ngutadjap, Ngoyla and Bioko Island. Here the species natural habitat, the threats to this habitat, and relevant conservation action are further described. The species habitat is swamp in the humid forest with ferns, and standing surface water. This species doesn't appear to have a strong seasonality. Threats to the habitat observed in Cameroon were wood logging, market gardening, bush fire, bamboo exploitation, and sand mining. There is no special conservation action in place for G. opilionoides apart from the general regulations affecting protected areas. As a contribution to the conservation of this species, we brought the matter to the attention of the Cameroon Minister of Forest and Wildlife.

In-situ online investigation of biogenic volatile organic compounds emissions from tropical rainforests in Hainan, China

Biogenic volatile organic compounds (BVOCs) emitted by tropical plants represent a significant proportion of global emissions, but the in-situ BVOC measurements in tropical rainforests are extremely sparse. Herein, a vehicle-mounted mobile monitoring system was developed for in-situ online investigations of BVOC emissions from thirty representative tree species in the tropical rainforests of Hainan Island, southern China. The results showed that monoterpenes were the primary BVOCs emitted from most broadleaf trees. Isoprene, sabinene, γ-terpinene and β-ocimene were the most abundant BVOCs. Localized canopy-scale emission factors (EFs) exhibited notable discrepancies with the defaults in the Model of Emissions of Gases and Aerosols from Nature (MEGAN), specifically with isoprene EFs being slightly lower than the model, while the EFs for monoterpenes and sesquiterpenes were 1 to 27 times higher than those in MEGAN. The BVOC emission inventory for the predominant mature forest species in Hainan Island in 2023 was further estimated to be 244.43 Gg C·yr−1, with isoprene and monoterpenes accounting for 74 % and 16 %, respectively. Additionally, unimodal monthly variation patterns were revealed, with BVOC emissions peaked in July (30.08 Gg C·yr−1) and bottomed in January (8.84 Gg C·yr−1). This study demonstrates the potential and versatility of the applied mobile platform for in-situ online measurements of plant volatiles. Our findings provide important data support for reducing uncertainties in BVOC emission estimations in tropical rainforests and for evaluating their health benefits in the context of forest therapy.

Growing-Season Precipitation Is a Key Driver of Plant Leaf Area to Sapwood Area Ratio at the Global Scale.

Leaf area to sapwood area ratio (AL/AS) influences carbon sequestration, community composition, and ecosystem functioning in terrestrial vegetation and is closely related to leaf economics and hydraulics. However, critical predictors of AL/AS are not well understood. We compiled an AL/AS data set with 1612 species-site combinations (1137 species from 285 sites worldwide) from our field experiments and published literature. We found the global mean AL/AS to be 0.63 m2 cm-2, with its variation largely driven by growing-season precipitation (Pgs), which accounted for 18% of the variation in AL/AS. Species in tropical rainforests exhibited the highest AL/AS (0.82 m2 cm-2), whereas desert species showed the lowest AL/AS (0.16 m2 cm-2). Soil factors such as soil nitrogen and soil organic carbon exhibited positive effects on AL/AS, whereas soil pH was negatively correlated with AL/AS. Tree density accounted for 7% of the variation in AL/AS. All biotic and abiotic predictors collectively explained up to 45% of the variation in AL/AS. Additionally, AL/AS was positively correlated to the net primary productivity (NPP) of the ecosystem. Our study provides insights into the driving factors of AL/AS at the global scale and highlights the importance of AL/AS in ecosystem productivity. Given that Pgs is the most critical driver of AL/AS, alterations in global precipitation belts, particularly seasonal precipitation, may induce changes in plant leaf area on the branches.

Conservation genomic study of Hopea hainanensis (Dipterocarpaceae), an endangered tree with extremely small populations on Hainan Island, China.

Hopea hainanensis Merrill & Chun is considered a keystone and indicator species in the tropical lowland rainforests of Hainan Island. Owing to its high-quality timber, H. hainanensis has been heavily exploited, leading to its classification as a first-class national protected plant in China and a plant species with extremely small populations (PSESPs). This study analyzed genome-wide single nucleotide polymorphisms obtained through restriction site-associated DNA sequencing from 78 adult trees across 10 H. hainanensis populations on Hainan Island. The nucleotide diversity of the sampled populations ranged from 0.00096 to 0.00138, which is lower than that observed in several other PSESPs and endangered tree species. Bayesian unsupervised clustering, principal component analysis, and neighbor-joining tree reconstruction identified three to five genetic clusters in H. hainanensis, most of which were geographically widespread and shared by multiple populations. Demographic history analysis based on pooled samples indicated that the decline in the H. hainanensis population began approximately 20,000 years ago, starting from an ancestral population size of approximately 10,000 individuals. The reduction in population size accelerated approximately 4,000 years ago and has continued to the present, resulting in a severely reduced population on Hainan Island. Intensified genetic drift in small and isolated H. hainanensis populations may contribute to moderate differentiation between some of them, as revealed by pairwise F st. In conclusion, our conservation genomic study confirms a severe population decline and an extremely low level of nucleotide variation in H. hainanensis on Hainan Island. These findings provide critical insights for the sustainable management and genetic restoration of H. hainanensis on Hainan Island.

On the Occurrence of Pelusios gabonensis in the Taï National Park (Côte d'Ivoire)

ABSTRACTMany species of terrestrial and freshwater chelonians are at risk of extinction, particularly rainforest species due to massive habitat loss. Therefore, the presence of peripheral and isolated populations can have considerable conservation value. This article confirms the presence of Pelusios gabonensis in an area of mature forest in western Côte d'Ivoire for which fragmentary data existed in the literature. It would therefore be important to study the conservation status and the genetics of the Ivorian populations given their huge geographic distance with conspecifics from the Lower Guinean forests.

Early life exposure to high temperature enhances locomotor performance without alteration in thermal ecology in different populations of Thoropa taophora tadpoles (Anura, Cycloramphidae).

Understanding the intricate relationship between temperature and physiological processes in ectotherm vertebrates is crucial for predicting how these animals respond to environmental changes, including those associated with climate change. This is particularly relevant for the anurans, given their limited capacity for thermoregulation, particularly in larval stages. Herein, we investigated the capacity for thermal acclimatization in Thoropa taophora tadpoles, an endemic species in the Atlantic rainforest of Southeast Brazil, inhabiting distinct thermal environments. These semi-terrestrial tadpoles develop on rocky surfaces with some populations inhabiting exposed regions near the marine coast where temperatures may reach up to 30 °C in sunny conditions, while other populations occupy forested areas near waterfalls that maintain lower temperatures. We aimed to understand the effects of temperature on locomotor performance and on the activity of metabolic enzymes that support performance in tadpoles sampled in four different populations. Moreover, we measured several aspects of thermoregulation including the critical thermal maximum (CTmax), the body temperature of activity (Tb), the preferred temperature (Tpref) and the effectiveness of thermoregulation (E). Despite differences in body size, tadpoles from warmer environments consistently demonstrate higher locomotor performance, with minimal or no acclimatization seen in other variables. Correlations between habitat temperature and biological endpoints underscore the significance of maximum locomotor performance in shaping physiological responses. Our results show how temperature can impact tadpole behavior and performance, without change in many organismal measures of thermal acclimatization, providing insights into potential ecological implications, particularly in the context of climate change.

Anthropogenic restoration exhibits more complex and stable microbial co-occurrence patterns than natural restoration in rubber plantations

Forest restoration is an effective method for restoring degraded soil ecosystems (e.g., converting primary tropical forests into rubber monoculture plantations; RM). The effects of forest restoration on microbial community diversity and composition have been extensively studied. However, how rubber plantation-based forest restoration reshapes soil microbial communities, networks, and inner assembly mechanisms remains unclear. Here, we explored the effects of jungle rubber mixed (JRM; secondary succession and natural restoration of RM) plantation and introduction of rainforest species (AR; anthropogenic restoration established by mimicking the understory and overstory tree species of native rainforests) to RM stands on soil physico-chemical properties and microbial communities. We found that converting tropical rainforest (RF) to RM decreased soil fertility and simplified microbial composition and co-occurrence patterns, whereas the conversion of RM to JRM and AR exhibited opposite results. These changes were significantly correlated with pH, soil moisture content (SMC), and soil nutrients, suggesting that vegetation restoration can provide a favorable soil microenvironment that promotes the development of soil microorganisms. The complexity and stability of the bacterial-fungal cross-kingdom, bacterial, and fungal networks increased with JRM and AR. Bacterial community assembly was primarily governed by stochastic (78.79 %) and deterministic (59.09 %) processes in JRM and AR, respectively, whereas stochastic processes (limited dispersion) predominantly shaped fungal assembly across all forest stands. AR has more significant benefits than JRM, such as a relatively slower and natural vegetation succession with more nutritive soil conditions, microbial diversity, and complex and stable microbial networks. These results highlight the importance of sustainable forest management to restore soil biodiversity and ecosystem functions after extensive soil degradation and suggest that anthropogenic restoration can more effectively improve soil quality and microbial communities than natural restoration in degraded rubber plantations.

Structure and composition of a canopy-beetle community (Coleoptera) in a Neotropical lowland rainforest in southern Venezuela.

Species richness, community structure and taxonomic composition are important characteristics of biodiversity. Beetle communities show distinct diversity patterns according to habitat attributes. Tropical rainforest canopies, which are well known for their richness in Coleoptera, represent such a conspicuous life zone. Here, I describe a canopy-inhabiting beetle community associated with 23 tree species in a Neotropical lowland rainforest. Adult beetles were sampled manually and in aerial traps using a large tower crane for a cumulative year. The sample revealed 6738 adult beetles, which were assigned to 862 (morpho-)species in 45 families. The most species-rich beetle families were Curculionidae (n = 246), Chrysomelidae (n = 121) and Cerambycidae (n = 89). The most abundant families were Curculionidae (n = 2746) and Chrysomelidae (n = 1409). Dominant beetle families were found in most assemblages. The beetle community consisted of 400 singletons (46.4%). A similar proportion was evident for assemblages of single tree species. I found that 74.5% of all beetle species were restricted in their occurrence on host trees to the phenological season and time of the day. This daily and seasonal migration causes patterns similar to mass effects and therefore accounts for the high proportion of singletons.