Presence Of Lianas Research Articles

Intraspecific variation in fruit production of African mahogany (Khaya anthotheca) in a semi‐deciduous East African rainforest

AbstractRestoring valuable timber trees is a necessary part of regaining many ecosystem services and products provided by degraded tropical forests. However, knowledge of seed production, a regeneration prerequisite, is limited for many tropical timber tree species. We studied the fruit production of African mahogany (Khaya anthotheca) in a semi‐deciduous rainforest in East Africa, to provide information for ecological restoration programs. First, we quantified population variability and synchrony in fruit production. Then, we assessed how reproductive status and output were influenced by tree size, neighbourhood crowding, exchangeable cations, liana presence, and crown exposure. We found fruit production at the population level was weakly synchronised, with high interannual variability at the population and individual levels. Tree size determined reproductive status. Individual quantity of fruit produced increased with tree size but decreased with neighbourhood crowding. Our results indicate that K. anthotheca does not meet the criteria for mast fruiting. Our findings suggest that reproductive output in mahogany is regulated by tree size and competition. In addition to active protection, thinning to reduce competition around seed trees may boost fruit production at the individual tree level to provide seed for forest enrichment.

Lianas increase lightning-caused disturbance severity in a tropical forest.

Lightning is an important agent of plant mortality and disturbance in forests. Lightning-caused disturbance is highly variable in terms of its area of effect and disturbance severity (i.e. tree damage and death), but we do not know how this variation is influenced by forest structure and plant composition. We used a novel lightning detection system to quantify how lianas influenced the severity and spatial extent (i.e. area) of lightning disturbance using 78 lightning strikes in central Panama. The local density of lianas (measured as liana basal area) was positively associated with the number of trees killed and damaged by lightning, and patterns of plant damage indicated that this occurred because lianas facilitated more electrical connections from large to small trees. Liana presence, however, did not increase the area of the disturbance. Thus, lianas increased the severity of lightning disturbance by facilitating damage to additional trees without influencing the footprint of the disturbance. These findings indicate that lianas spread electricity to damage and kill understory trees that otherwise would survive a strike. As liana abundance increases in tropical forests, their negative effects on tree survival with respect to the severity of lightning-related tree damage and death are likely to increase.

Diametric Growth of a Forest under Reduced-Impact Logging in the Eastern Region of the Brazilian Amazon

Growth is a component of forest dynamics that encompasses changes in species composition, interactions between species, and stand structure. We evaluated the effect of the presence of lianas, crown shape, and light exposure on the periodic annual increment of trees (PAI) in two phytophysiognomies: the ombrophilous dense forest and the ombrophilous open forest with lianas. This study was conducted in the eastern Brazilian Amazon in 13 permanent monitoring plots of 50 m × 50 m (2500 m2) in the same annual production unit. The area has been subjected to reduced-impact logging from 2014 to 2016. The increment in tree diameter varied significantly between both forests (opens forests: 1.28 cm yr−1; dense forests: 0.82 cm yr−1). Light exposure influenced the increment in tree diameter in the ombrophilous open forest with lianas, while the crown shape and light exposure significantly affected the ombrophilous dense forest. Our study emphasizes the usefulness of the periodic annual increment in exploring the differences between contrasting phytophysiognomies in a single annual production unit in the Brazilian Amazon that is subject to reduced-impact logging.

Lianas (Vitis spp.) reduce growth and carbon sequestration of light‐demanding tree species in a temperate forest

Governments worldwide are seeking natural climate solutions that can provide economic stimulus while meeting climate goals. Forests provide essential carbon dioxide (CO2) sequestration services, but their potential may be limited by elevated liana densities often resulting from human disturbance. Here we report the first estimate of liana (Vitis spp.) impacts on CO2 removal rates by trees in temperate Appalachian forests and suggest liana removal with biodiversity safeguards as a potential strategy for improved forest management. Shade‐intolerant tree species without lianas removed CO2 20% faster than conspecifics with lianas (p = 0.025). We did not detect significant impacts of liana presence on the CO2 removal rates for shade‐tolerant species (p = 0.838). Additionally, the merchantable boles of trees without lianas increased in volume 9% faster annually compared to trees with lianas, for all species (p = 0.003). Our findings indicate that thinning lianas—particularly from light‐loving species such as Liriodendron tulipifera—may improve sustainability of forest management and increase carbon storage while mitigating climate change.

Landscape‐scale drivers of liana load across a Southeast Asian forest canopy differ to the Neotropics

Abstract Lianas (woody vines) are a key component of tropical forests, known to reduce forest carbon storage and sequestration and to be increasing in abundance. Analysing how and why lianas are distributed in forest canopies at landscape scales will help us determine the mechanisms driving changes in lianas over time. This will improve our understanding of liana ecology and projections of tropical forest carbon storage now and into the future. Despite competing hypotheses on the mechanisms driving spatial patterning of lianas, few studies have integrated multiple tree‐level biotic and abiotic factors in an analytical framework. None have done so in the Palaeotropics, which are biogeographically and evolutionarily distinct from the Neotropics, where most research on lianas has been conducted. We used an unoccupied aerial system (UAS; drone) to assess liana load in 50‐ha of Palaeotropical forest canopy in Southeast Asia. We obtained data on hypothesised drivers of liana spatial distribution in the forest canopy, including disturbance, tree characteristics, soil chemistry and topography, from the UAS, from airborne LiDAR and from ground surveys. We integrated these in a comprehensive analytical framework to extract variables at an individual‐tree level and evaluated the relative strengths of the hypothesised drivers and their ability to predict liana distributions through boosted regression tree (BRT) modelling. Tree height and distance to canopy gaps were the two most important predictors of liana load, with relative contribution values in BRT models of 34.60%–45.39% and 7.93%–10.19%, respectively. Our results suggest that taller trees were less often and less heavily infested by lianas than shorter trees, opposite to Neotropical findings. Lianas also occurred more often, and to a greater extent, in tree crowns close to canopy gaps and to neighbouring trees with lianas in their crown. Synthesis. Despite their known importance and prevalence in tropical forests, lianas are not well understood, particularly in the Palaeotropics. Examining 2428 trees across 50‐ha of Palaeotropical forest canopy in Southeast Asia, we find support for the hypothesis that canopy gaps promote liana infestation. However, we also found that liana presence and load declined with tree height, which is opposite to well‐established Neotropical findings. This suggests a fundamental difference between Neotropical and Southeast Asian forests. Considering that most liana literature has focused on the Neotropics, this highlights the need for additional studies in other biogeographic regions to clarify potential differences and enable us to better understand liana impacts on tropical forest ecology, carbon storage and sequestration.

Positive effects of ants on host trees are critical in years of low reproduction and not influenced by liana presence

Tropical tree-climbing lianas form paths that benefit foraging of dominant ants which might protect the host tree against herbivores. In contrast, lianas are often associated with negative effects on growth and reproduction of host trees due to light obstruction, structural stress and other negative effects. It is unclear if dominant ants could mitigate the negative effects of lianas on host plants. We investigated how lianas and carton nest ants (Azteca chartifex) affected herbivory and reproductive structures of the host tree Byrsonima sericea. Considering 68 trees, almost half of them were naturally colonized by A. chartifex nests (32 trees). We removed lianas from half of the trees (34), establishing a factorial sampling design between A. chartifex and liana presence. We sampled ants and leaf herbivory before and after removing lianas, and measured plant fitness in two consecutive years after removing lianas. Liana removal had no effect on A. chartifex foraging, on leaf herbivory and flower-fruit conversion of host plants. However, A. chartifex decreased leaf herbivory and increased B. sericea flower-fruit conversion irrespective of lianas presence. A noticeable positive effect of ants was detected only in the second year of the experiment, consistently on all plants at each experimental level. The reproductive conditions of the first year resulted in most plants with more than 75% flower-to-fruit conversion success, regardless of the presence of A. chartifex, a success sustained only on those ant-colonized plants in the second year. Our results contribute to understanding multi-trophic interactions in tropical forest canopies as we demonstrated i) that dominant arboreal ants can benefit plants even in a non-obligatory interaction and ii) that the influence of lianas on its host tree is context-dependent, presenting even neutral effects depending on habitat type and species involved.

Increasing Liana Abundance and Associated Reductions in Tree Growth in Secondary Seasonally Dry Tropical Forest

Lianas are thought to be increasing and altering tree growth and ecosystem productivity in tropical forests, but less research has focused on secondary or seasonally dry tropical forest. We report on an 11-year study of tree growth and liana presence from Guanacaste, Costa Rica, where we measured the diameter growth and liana presence on more than 1,700 trees in regenerating forest of different ages. We find that the proportion of trees without lianas is decreasing and the number of trees with lianas occupying more than 10% of tree’s crowns is increasing. We also find that lianas are affecting the diameter growth of trees. The 11-year average relative growth rates of trees with lianas in more than 10% of the tree’s crown are lower than the relative growth of trees with no lianas or lianas in less than 10% of their crown. Year-to-year, tree relative growth rate is related to annual precipitation and tree diameter. However, trees that were heavily infested with lianas (i.e., with lianas in more than 50% of their crowns) had lower relative growth and a weaker precipitation-growth relationship. This work underscores the value of long-term longitudinal data in secondary forest and adds critical data on dry forest liana abundance change.

Root climbers may alter invertebrate communities on tree trunks: an indirect effect of lianas

Root climbers are a group of lianas which typically climb the host tree using adhesive roots and do not compete with the host for light. They are relatively more abundant in high-latitude forests and were recently documented to have no harmful effect on their host trees. Although previous studies have examined the direct negative effects of lianas on their host trees, little is known about potential indirect effects via effects on the animal and plant communities. Here, we aimed to determine the effects of root climbers on the animal and plant community composition of their host trunk and whether these alterations indirectly affect host trees. To answer these questions, we compared the invertebrate community, herbaceous plant presence, moss cover and herbivory rates in more than 22 pairs of host and control trees in cool-temperate forests in Hokkaido, Japan. We selected Quercus crispula Blume and Hydrangea petiolaris Sieb. et Zucc. as the study species. Generalised linear mixed models (GLMMs) were used to determine the influence of lianas on tree trunk communities and host trees. Our results showed that the presence of root climbers increased the abundance of Araneae and herbaceous plants and reduced the abundance of Formicidae on host trees, implying a reduction of herbivory on hosts. These results imply that liana presence may reduce the herbivory rate on the host tree, potentially by altering the trunk animal and plant community structure. Our results have implications for the understanding of the effects of lianas on host trees and their function in high-latitude forests.

Being hunted high and low: do differences in nocturnal sleeping and diurnal resting sites of howler monkeys (Alouatta nigerrima and Alouatta discolor) reflect safety from attack by different types of predator?

Abstract Predation risk is important in influencing animal behaviour. We investigated how the choice of nocturnal sleeping and diurnal resting sites by two species of primates was influenced by the most likely forms of attack (diurnal raptors and nocturnal felids). We recorded vertical and horizontal patterns of occupancy for 47 sleeping and 31 resting sites, as well as the presence of lianas or vines on trees. We compared the heights of trees used as resting or sleeping sites by the monkeys with those of 200 forest trees that the monkeys did not use. Trees used as nocturnal sleeping sites were taller than those used as diurnal resting sites, and taller than trees that the monkeys did not use. However, while trees used as diurnal resting sites were not significantly taller than non-used trees, diurnal resting sites were located on branches closer to the ground, closer to the main trunk of the tree and in trees with more lianas/vines than nocturnal sleeping sites. The differences in site location can be explained by the type of predator most likely to attack at a particular time: raptors in the day and felids at night.

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

AbstractAlmost 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.

Differences in Leaf Temperature between Lianas and Trees in the Neotropical Canopy

Leaf temperature (Tleaf) influences photosynthesis and respiration. Currently, there is a growing interest in including lianas in productivity models due to their increasing abundance and their detrimental effects in the carbon stock of tropical ecosystems. Therefore, understanding the differences of Tleaf between lianas and trees is important for future predictions of productivity. Here, we determined the displayed leaf temperature (Td = Tleaf − air temperature) of several species of lianas and their host trees during El Niño-Southern Oscillation (ENSO) and non-ENSO years to evaluate if the presence of lianas affects the Td of their host trees, and if leaves of lianas and their host trees exhibit differences in Td. Our results suggest that close to midday, the presence of lianas does not affect the Td of their host trees; however, lianas tend to have higher values of Td than their hosts across seasons, in both ENSO and non-ENSO years. Although lianas and trees tend to have similar physiological-temperature responses, differences in Td could lead to significant differences in rates of photosynthesis and respiration based on temperature response curves. Future models should thus consider differences in leaf temperature between these two life forms to achieve robust predictions of productivity.

PROPOSAL FOR A SYSTEM OF TREES FALL POTENTIAL RISK ASSESSMENT IN URBAN PARKS1

ABSTRACT This study aimed to create a system to assess the potential tree fall risk (SARPQA) and to assess all the trees in the Museum Paraense Emílio Goeldi Zoo (PZB/MPEG) and in the Rodrigues Alves Park/Botanical Garden of Amazônia (BRA/JBA). We analyzed aspects, such as diameter at breast height (DBH), tree total heigh, surface biomass, apparent phytosanitary, stem inclination, canopy balance and presence of lianas. We assessed 1074 trees (DBH e” 20 cm) distributed in 229 species and 40 families. The average stem height, the total height and diameter at breast height were 10.9 m, 18.7 m and 41.9 cm respectively. The SARPQA showed that 23 trees had very high risk of fall, 142 had high risk, 750 individuals had medium and low risk and 159 had very low risk. Both parks have hundreds of large trees, which associated with the amount of people using these spaces, can increase the risk of accidents by tree fall. Trees with high risk of fall need immediate attention because they present risks to human life and/or property. The system proposed in this study proved to be practical and can be an effective tool for decision makers in the management of urban parks.

Shadows of the edge effects for tropical emergent trees: the impact of lianas on the growth of Aspidosperma polyneuron

Forest edge impacts emergent trees growth by reducing the number of growth releases. This reduction seems to be related with lianas infestation found at the forest edge. Deforestation in tropical regions is raising fragmentation to alarming levels. Not only does it lead to losses of forest area, but also the abiotic and biotic changes on forest edge areas alter the development of the remaining trees. We aimed to assess the impacts of forest fragmentation on the growth of tropical emergent trees. We sampled the endangered species Aspidosperma polyneuron (Apocynaceae) at forest edge and interior in the highly fragmented Brazilian Atlantic Forest. We obtained increment cores of each tree along with data about tree and surrounding canopy heights, plus their current levels of liana infestation. We used tree-ring analyses to estimate age and growth rate of trees. Sampled trees and surrounding canopy were taller at the forest interior than at the edge, even though both sampled populations have similar ages. Overall, trees at forest interior show a lifetime growth pattern common to shade-tolerant species, with a peak of growth rate at 120 years. Indeed, all sampled trees exhibited this pattern before fragmentation. However, trees at forest edge presented constantly slow growth rates for all diameter classes after the fragmentation event. The strong presence of lianas at forest edge prevents trees from experiencing the expected growth releases throughout their lifetime, probably by keeping the leaves of A. polyneuron under shaded conditions. Therefore, the management of lianas at the forest edge is likely the most effective procedure to ensure the growth of emergent trees, guarantying their role on forests structure, carbon storage, and ecosystem functioning.

Tree community structure reflects niche segregation of three parapatric squirrel monkey species (Saimiri spp.).

Integration between ecology and biogeography provides insights into how niche specialization affects the geographical distribution of species. Given that rivers are not effective barriers to dispersal in three parapatric species of squirrel monkeys (Saimiri vanzolinii, S. cassiquiarensis and S. macrodon) inhabiting floodplain forests of Central Amazonia, we tested whether forest structure and tree diversity may explain species differences in niche specialization and spatial segregation. We sampled 6617 trees of 326 species in three habitats (high várzea, low várzea and chavascal) used by three Saimiri species, and estimated tree species richness in each of them. For each tree, we measured variables known to influence habitat use in primates, such as crown area and presence of lianas, epiphytes and hemi-epiphytes. We used ANOVA to compare these variables and performed multivariate analyses (NMDS, ANOSIM and SIMPER) to evaluate dissimilarities in forest structure among each habitat inhabited by the three Saimiri species. We identified differences in the tree species richness, crown area and presence of lianas, epiphytes and hemi-epiphytes between the three habitats for all Saimiri species. NMDS demonstrated that areas of high and low várzeas occupied by S. vanzolinii were clearly separated from the other species. We also found that different plant species contributed to dissimilarity among Saimiri ranges. Our findings support the hypothesis that tree community structure may promote niche specialization and spatial segregation among primates. We discuss how these patterns could have been favored by historical changes in forest flood patterns, the evolutionary history of Saimiri spp., and past competition.

Effects of lightning on trees: A predictive model based on in situ electrical resistivity.

The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field‐collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tree size and identity, and with the presence of lianas. Estimated heating density (heat generated per volume of tree tissue) and maximum power (maximum rate of heating) from a standardized lightning discharge differed 300% among tree species. Tree size and morphology also were important; the heating density of a hypothetical 10 m tall Alseis blackiana was 49 times greater than for a 30 m tall conspecific, and 127 times greater than for a 30 m tall Dipteryx panamensis. Lianas may protect trees from lightning by conducting electric current; estimated heating and maximum power were reduced by 60% (±7.1%) for trees with one liana and by 87% (±4.0%) for trees with three lianas. This study provides the first quantitative mechanism describing how differences among trees can influence lightning–tree interactions, and how lianas can serve as natural lightning rods for trees.

Can terrestrial laser scanners (TLSs) and hemispherical photographs predict tropical dry forest succession with liana abundance?

Abstract. Tropical dry forests (TDFs) are ecosystems with long drought periods, a mean temperature of 25 °C, a mean annual precipitation that ranges from 900 to 2000 mm, and that possess a high abundance of deciduous species (trees and lianas). What remains of the original extent of TDFs in the Americas remains highly fragmented and at different levels of ecological succession. It is estimated that one of the main fingerprints left by global environmental and climate change in tropical environments is an increase in liana coverage. Lianas are non-structural elements of the forest canopy that eventually kill their host trees. In this paper we evaluate the use of a terrestrial laser scanner (TLS) in combination with hemispherical photographs (HPs) to characterize changes in forest structure as a function of ecological succession and liana abundance. We deployed a TLS and HP system in 28 plots throughout secondary forests of different ages and with different levels of liana abundance. Using a canonical correlation analysis (CCA), we addressed how the VEGNET, a terrestrial laser scanner, and HPs could predict TDF structure. Likewise, using univariate analyses of correlations, we show how the liana abundance could affect the prediction of the forest structure. Our results suggest that TLSs and HPs can predict the differences in the forest structure at different successional stages but that these differences disappear as liana abundance increases. Therefore, in well known ecosystems such as the tropical dry forest of Costa Rica, these biases of prediction could be considered as structural effects of liana presence. This research contributes to the understanding of the potential effects of lianas in secondary dry forests and highlights the role of TLSs combined with HPs in monitoring structural changes in secondary TDFs.

No strong evidence for increasing liana abundance in the Myristicaceae of a Neotropical aseasonal rain forest.

The "liana dominance hypothesis" posits that lianas are increasing in abundance in tropical forests, thereby potentially reducing tree biomass due to competitive interactions between trees and lianas. This scenario has implications not only for forest ecosystem function and species composition, but also climate change given the mass of carbon stored in tropical trees. In 2003 and 2013, all Myristicaceae trees in the 50-ha Yasuní Forest Dynamics Plot, Ecuador, were surveyed for liana presence and load in their crowns. We tested the hypothesis that the proportion of trees with lianas increased between 2003 and 2013 in line with the liana dominance hypothesis. Contrary to expectations, the total proportion of trees with lianas decreased from 35% to 32%, and when only trees ≥10cm diameter at breast height were considered liana incidence increased 44-48%. Liana load was dynamic with a large proportion of trees losing or gaining lianas over the 10-yr period; large trees with intermediate liana loads increased in proportion at the expense of those with low and high loads. Lianas also impacted performance: trees with 26-75% crown cover by lianas in 2003 had reduced growth rates of 80% compared to of liana-free trees, and trees with >75% crown cover had 33% the growth rate and a log odds of mortality eight times that of liana-free trees. We suggest that the lack of strong support found for the liana dominance hypothesis is likely due to the aseasonal climate of Yasuní, which limits the competitive advantage lianas maintain over trees during dry seasons due to their efficient capture and use of water. We propose further research of long-term liana dynamics from aseasonal forests is required to determine the generality of the increasing liana dominance hypothesis in Neotropical forests.

Lianas and soil nutrients predict fine‐scale distribution of above‐ground biomass in a tropical moist forest

Summary Prediction of carbon dynamics in response to global climate change requires an understanding of the processes that govern the distribution of carbon stocks. Above‐ground biomass (AGB) in tropical forests is regulated by variation in soil fertility, climate, species composition and topography at regional scales, but the drivers of fine‐scale variation in tropical forest AGB are poorly understood. The factors that control the growth and mortality of individual trees may be obscured by the low resolution of studies at regional scales. In this paper, we evaluated the effects of soil nutrients, topography and liana abundance on the fine‐scale spatial distribution of AGB and density of trees for a lowland tropical moist forest in Panama using additive regression models. Areas with larger values of AGB were negatively associated with the presence of lianas, which may reflect competition with lianas and/or the association of lianas with disturbed or open‐canopy patches within forests. AGB was positively associated with soils possessing higher pH and K concentrations, reflecting the importance of below‐ground resource availability on AGB independently of stem density. Synthesis. Our results shed new light on the factors that influence fine‐scale tree AGB and carbon stocks in tropical forests: liana abundance is the strongest predictor, having a negative impact on tree AGB. The availability of soil nutrients was also revealed as an important driver of fine‐scale spatial variation in tree AGB.

DINÂMICA DO CARBONO EM UMA FLORESTA MANEJADA CO MERCIALMENTE NO AMAZONAS

O objetivo deste estudo foi avaliar os efeitos do sistema silvicultural policíclico na dinâmica de carbono de uma floresta manejada comercialmente no Amazonas. Os dados são provenientes de medições de 41 parcelas permanentes, um hectare cada, localizadas nas Unidades de Produção Anual B, C e D da Fazenda Dois Mil pertencente à Empresa Mil Madeiras Preciosa Ltda, em Itacoatiara, AM. Sendo quatro medições na UPA B (1996, 1998, 2001 e 2014) e três nas UPAs C (1997, 2001 e 2014) e D (1998, 2001 e 2014), onde todas as árvores com DAP≥15 cm foram medidas. Foram avaliadas as variáveis: classe de identificação do fuste, tratamento silvicultural, iluminação e forma da copa, dano e presença de cipó. A biomassa foi estimada utilizando-se uma equação ajustada para floresta tropical úmida. O estoque de carbono estimado foi de 165,7 t.ha-1. O incremento periódico anual em carbono é influenciado pelas variáveis categóricas: iluminação da copa e forma da copa. Nas UPAs B e D, 17 e 16 anos após exploração, o carbono é diferente do estoque antes da exploração. A UPA C apresenta o mesmo estoque de carbono que continha antes da exploração, considerado o povoamento total. De modo geral, o manejo aplicado não influenciou de maneira diferente as UPAs, a diferença nos estoque foi somente em função do tempo.

Lianas suppress seedling growth and survival of 14 tree species in a Panamanian tropical forest.

Lianas are a common plant growth form in tropical forests, where they compete intensely with trees, decreasing tree recruitment, growth, and survival. If the detrimental effects of lianas vary significantly with tree species identity, as is often assumed, then lianas may influence tree species diversity and community composition. Furthermore, recent studies have shown that liana abundance and biomass are increasing relative to trees in neotropical forests, which will likely magnify the detrimental effects of lianas and may ultimately alter tree species diversity, relative abundances, and community composition. Few studies, however, have tested the responses of multiple tree species to the presence of lianas in robust, well-replicated experiments. We tested the hypotheses that lianas reduce tree seedling growth and survival, and that the effect of lianas varies with tree species identity. We used a large-scale liana removal experiment in Central Panama in which we planted 14 replicate seedlings of 14 different tree species that varied in shade tolerance in each of 16 80 x 80 m plots (eight liana-removal and eight unmanipulated controls; 3136 total seedlings). Over a nearly two-yr period, we found that tree seedlings survived 75% more, grew 300% taller, and had twice the aboveground biomass in liana-removal plots than seedlings in control plots, consistent with strong competition between lianas and tree seedlings. There were no significant differences in the response of tree species to liana competition (i.e., there was no species by treatment interaction), indicating that lianas had a similar negative effect on all 14 tree species. Furthermore, the effect of lianas did not vary with tree species shade tolerance classification, suggesting that the liana effect was not solely based on light. Based on these findings, recently observed increases in liana abundance in neotropical forests will substantially reduce tree regeneration, but will not significantly alter tropical tree species diversity, relative abundance, or community composition.