Understanding the processes that allow phylogenetically related plant species coexist is important to understand the ecological and evolutionary processes that structure biological communities. In this study, we investigated how the species Erythroxylum simonis, Erythroxylum pauferrense and Erythroxylum citrifolium share ecological niche dimensions according to the abiotic characteristics of their environments of occurrence. To this end, in ten pre-established plots in an Atlantic Forest remnant in northeastern Brazil, we carried out a population survey of the three species and characterised their abiotic niche by measuring light availability, humidity and the physical–chemical properties of the soil. We used generalised linear models to test whether abiotic variables influence species abundance. Our results indicate that the three species coexist along the different environmental gradients, with some level of niche overlap. The species E. simonis is the best competitor, showing generalist behaviour and the highest abundance in all environmental gradients. We emphasise that the adult populations of the species have adapted to various environmental and ecological challenges. Thus, the results reported are influenced by their ability to perform well in terms of physiology, growth and survival in their early-life stages.

Most studies aiming to quantify carbon stocks in tropical forests have focused on aboveground biomass, omitting carbon in soils and woody debris. Here, we quantified carbon stocks in soils up to 3 m depth, woody debris, and aboveground and belowground tree biomass for the 25-ha Amacayacu Forests Dynamics plot in the northwestern Amazon. Including soils to 3 m depth, total carbon stocks averaged 358.9 ± 24.2 Mg C ha−1, of which soils contributed 53%, biomass 44.2%, and woody debris 2.7%. When only including soils to 0.5 m depth, carbon stocks diminished to 222.1 Mg C ha−1 and biomass became the largest contributor. Among 1-ha subplots, total carbon stocks were correlated with soil carbon stocks at ≥0.5 m depth, belowground biomass of all trees, and aboveground biomass of trees ≥60 cm DBH. Our results support the assumption of biomass as the likely largest carbon source associated with land use change in northwestern Amazonia. However, mining and erosion following land use change could also promote a significant release of carbon from soil, the largest carbon stock. To improve the global carbon balance, we need to better quantify total carbon stocks and dynamics in tropical forests beyond aboveground biomass.

This study elucidates the litter dynamics including decomposition rate both in-situ and ex-situ, the initial acquisition traits (LATs), morphological traits (LMTs) and production rate of leaf litter of four economically important tree species viz. Terminalia arjuna (TA), Tectona grandis (TG), Eucalyptus citriodora (EC) and Psidium guajava (PG) with the major objective of restoration of degraded urban ecosystems in dry tropics. Annual litterfall production rates were observed as: TG > TA > EC > PG. LMTs, that is, specific leaf area followed the trend: TG > TA > PG > EC, whereas leaf mass per area followed the reverse trend. In TA, LATs involving carbon (C), nitrogen (N) and cellulose were highest but C/N and lignin/N ratios were lowest, whereas lignin, polyphenol, C/N and lignin/N ratios were highest in PG. In the leaf litter bag experiment, the decomposition rate followed the trend: TA > TG > EC > PG. In-situ and ex-situ rates of decomposition of all the four leaf litters were found to be similar. LATs especially lignin/N, N and C/N ratios rather than LMTs were found to be a better predictor of the litter decomposition rate. TA plantation having a higher litter decomposition rate, may be recommended for inclusion in the restoration strategies of degraded urban land.

Animals adopt various behavioral strategies to meet their biological needs, often adjusting their activity cycles. While some species restrict their activities to specific periods within the 24-hour light and dark cycle, others are cathemeral, showing flexible activity patterns that include both day and night. This study investigates the cathemeral activity of Amazonian manatees (Trichechus inunguis) in Anavilhanas National Park, Brazil, with a focus on their nocturnal behavior and ecological adaptability. Using thermal cameras, we recorded nocturnal feeding for the first time, highlighting the manatees’ flexibility beyond the typical diurnal–nocturnal cycle. Our findings reveal that manatees adjust their feeding strategies according to seasonal vegetation availability and water levels. Specifically, they feed at night on the riparian plant maracarãna (Coccoloba densifrons), which is only accessible during the flood season. This nocturnal behavior likely helps minimize predation risk and enhances foraging efficiency. These insights significantly improve our understanding of manatee ecological behavior in the Amazon, demonstrating their adaptability to environmental changes. The study underscores the importance of considering cathemeral activity in conservation strategies to ensure the ongoing protection of Amazonian manatees against environmental and human pressures.

Despite the tropics harbouring tremendous diversity of species and interspecific interactions, tropical moths as pollinators remain understudied. This review synthesises the available knowledge on the role of nocturnal moths in pollination and their importance in tropical ecosystems. It identifies significant research gaps, methodological challenges, and geographical biases, offering cues for future research. Moths represent crucial pollinators for numerous tropical plants across more than 25 families. In tropical communities, plants with sphingophilous and phalaenophilous flowers account for 4% to 13%, while moth-pollinated plants represent up to 20% of species, highlighting their ecological significance. Current knowledge shows biases and constraints stemming from the challenges of nocturnal research, such as complex moth behaviour, observational difficulties, and equipment limitations in tropical areas. Future research should broaden sampling in understudied tropical ecosystems and combine advanced technologies like video recordings, AI-driven identification, and pollen metabarcoding with detailed studies of nocturnal pollinators’ effectiveness in selected pollination systems. Moreover, such studies should integrate generalised pollination systems and community-level approaches to gather comprehensive datasets on nocturnal pollinators in the tropics. Filling these gaps is critical to understanding moths’ ecological and evolutionary roles, particularly in the context of the changing climate.

Islands are known for high rates of species extinction, especially for large birds, entailing losses of ecological functions such as seed dispersal. Improving our knowledge of interactions between the flora and fauna is critical to better understand the functioning of island ecosystems and protect their unique biodiversity. Here, we assessed the role of the endemic New Caledonian imperial pigeon, Ducula goliath Gray, 1859, as a key disperser of native rainforest trees. D. goliath is one of the largest species of fruit pigeons worldwide and is classified as “nearly threatened” on the IUCN Red List of threatened species due to overhunting and habitat shrinkage. We analysed the seed dispersal syndrome of 460 tree species and found that 82% of these species are likely dispersed by internal animal transportation. Diaspore consumption observations support that D. goliath would be the only bird disperser for about 20% of these species. We suggest that besides birds the only native alternate dispersers for these species could be the three flying fox species (genus Pteropus). Conservation actions and hunting regulations should continue to be improved to mitigate further adverse effects on D. goliath and the key dispersal function it provides.

Species abundances and richness are central parameters in ecology and crucial for describing diversity and composition across environments. Understanding how they vary in natural environments is critical for informed conservation decisions, especially in the face of anthropogenic pressures, such as deforestation and climate change. We evaluate the influence of landscape and local habitat variables on the richness and abundances of lizards in the Caatinga, the largest continuous block of seasonally dry tropical forests. We sampled seven lizard communities for three months using visual encounters along transects. We recorded landscape and microhabitat variables and evaluated their influence on lizard species richness, diversity, and occurrence using model selection. Ten lizard species were recorded, with Tropidurus semitaeniatus, Ameivula ocellifera, and Tropidurus hispidus being the most abundant. Topographic complexity and the number of rocky outcrops positively affect species richness and diversity by promoting environmental heterogeneity and hence increasing refuges, shelters, and thermoregulation sites. Different microhabitat and landscape variables were important predictors of the occurrences of individual lizard species. The quantity of rocks significantly increased the likelihood of Tropidurus semitaeniatus occurrence, while litter negatively affected Tropidurus hispidus, and fallen logs increased the probability of Ameiva ameiva occurrence. We argue that preserving topographically complex regions is essential for maintaining the diversity of lizards in the Caatinga biome.

The connectivity between epigean and cave habitats is crucial for maintaining invertebrate communities once it can facilitate faunal movement, organic resource supply, and environmental stability. The study aimed to investigate how some spatial and temporal variations in environmental factors within caves and epigean habitats influence invertebrate species richness and composition. We found a notable difference in invertebrate species richness and composition between cave and epigean environments and between cave lithologies. Moisture and temperature significantly influenced species composition across lithologies and epigean and hypogean environments. Cave microclimatic emerged as a critical factor influencing cave fauna. The dissimilarities between epigean and cave environments underscore the selective pressures imposed by caves, challenging species to overcome such environmental filters. Despite epigean environments offering more significant variability in conditions and resources, the findings highlight the importance of local ecological context and specific situations in shaping invertebrate communities. Furthermore, spatial variability within caves emphasises the necessity for a nuanced approach to conservation, considering the heterogeneity of habitats within each cave system. The study contributes to understanding the relationship between caves and their surrounding areas, emphasising the need for tailored conservation strategies that account for regional and cave-specific factors in the context of global environmental changes.

The Serengeti National Park and the Ngorongoro National Park are well-known for their migratory herds of large herbivores. These migrations are suggested to be due to different nutritional needs of the large herbivores over the year. The nutritional needs of the large herbivores are fulfilled by the different nutrient content of the grassland biomass. Soil nutrient availability is at least partly controlling the nutrient content of the grassland biomass despite plant-specific nutrient uptake mechanisms. Despite lot of data existing on the nutrient content of the grassland biomass in this area, less is known about the nutrient availability of the soils, especially for the transect from the Ngorongoro crater via the Ngorongoro Conservation area to the centre of the Serengeti National Park in Tanzania. Here we present a dataset on the availability of carbon, nitrogen, magnesium, aluminium, silicon, phosphorus, potassium, calcium, manganese and iron in the soils along this transect at 16 sampling points. Our data clearly show that the nutrient availability in the soils along this transect strongly differs with higher values of aluminium, silicon, potassium and calcium near the border of Serengeti National Park. These differences in soil nutrient availability might be the reason for different nutrient content in grassland biomass in certain areas, hence potentially affecting the migration of the herds of large herbivores as found by other studies. As our dataset is not comprehensive, we call for collection and analysis of more samples and also soil profile analysis in this area as our dataset is limited.

Wetlands contribute to economic development through the provisioning of ecosystem services. In Rwanda, the exploitation of wetlands for agriculture is a recent phenomenon, introduced in response to food shortages in the dry season and drought periods. Few studies have documented the biodiversity of wetlands in Rwanda, such as the high altitude Rugezi marshland; a Ramsar site located in the north of Rwanda. To fill this gap, the first arthropod inventories were conducted in 2023, from June to July (dry season) and from November to December (rainy season) at Rugezi marshland. Data was collected in sites located in the northeast and northwest of the marshland using hand collection, pitfall traps, and sweep nets. Collected specimens were preserved in 75% ethanol and identified to the order and family levels using dichotomous keys. A total of 26,944 individuals of arthropods were sampled with 17,074 recorded during the dry season and 9,870 during the rainy season. High abundance was found in the northwest (N = 14,739) compared to the northeast (N = 12,151). Using this data, we found that there was a statistically significant difference in the diversity of arthropods between seasons and sites, with the dry season having higher arthropod diversity in northeast side while the rainy season had a more pronounced increase in northwest site. We recommend future studies to establish a list of arthropod bioindicators of land use change and the use of participatory governance for effective management of Rugezi marshland.

Anthropogenic actions are likely to harm dung beetle populations directly through habitat loss and indirectly through the cascading effects of large mammal depletions. Despite the reliance of dung beetles on mammal dung, there are only a handful of studies that have directly assessed the impact of habitat degradation and associated mammalian loss on dung beetle populations in Africa. We evaluated whether patterns in dung beetle species abundance, richness, and body size can be associated with mammalian herbivore abundance and species richness, habitat structure, and the distance between sample sites. Additionally, we ascertained how the presence of elephants (Loxodonta africana) may affect a dung beetle assemblage by determining which species could be used as bioindicators of elephant presence. We found herbivore and overall mammal abundance explained 17% of dung beetle assemblage structure, 2% of dung beetle abundance, 10% of dung beetle species richness and, 15% of the variation in dung beetle body size. Habitat structure explained 27% of dung beetle assemblage structure, 11% of dung beetle abundance, and 14% of the variation in dung beetle body size. Spatial distance between trapping locations explained 13% of the dung beetle assemblage structure, 4% of species richness, 3% of abundance, and but had no effect on dung beetle body size. We also identified four dung beetle species that may be used in future management plans as bioindicators of elephant density Afromontane Forest in East Africa. This information may become especially important for future monitoring as it is predicted that the areas in which elephants occur in Afromontane Forest are set to decline due to deforestation, and the expansion and intensification of agriculture.

Reliable population estimates are one of the most elementary needs for the management of wildlife, particularly for introduced ungulates on oceanic islands. We aimed to produce accurate and precise density estimates of Philippine deer (Rusa marianna) and wild pigs (Sus scrofa) on Guam using motion-triggered cameras combined with distance sampling to estimate densities from observations of unmarked animals while accounting for imperfect detection. We used an automated digital data processing pipeline for species recognition and to estimate the distance to detected species. Our density estimates were slightly lower than published estimates, consistent with management to reduce populations. We estimated the number of camera traps needed to obtain a 0.1 coefficient of variation was substantial, requiring > ten-fold increase in camera traps, while estimates with precision of 0.2 or 0.3 were more achievable, requiring doubling to quadrupling the number of camera traps. We provide best practices for establishing and conducting distance sampling with camera trap surveys for density estimation based on lessons learned during this study. Future studies should consider distance sampling with camera traps to efficiently survey and monitor unmarked animals, particularly medium-sized ungulates, in tropical, oceanic island ecosystems.

Tropical peatlands are important global carbon sinks, and the ways they differ from adjacent forest ecosystems in environmental functions have not been well characterized. Our study investigated family-level floristic and soil differences between adjacent paired patches of intact waterlogged peat forests and kerangas (free-draining heath) forests in Brunei Darussalam. For each patch, we examined total and labile nutrient concentrations in soils, tree stand diversity and structural characteristics, functional traits of live leaves and leaf litter, and nutrient resorption during leaf senescence. We found that total nutrients were more abundant in peat and kerangas humus than in kerangas sand, while available nutrients were highest in kerangas humus, suggesting that anoxic conditions in peat soils impair mineralization of nutrients to available forms but do not lead to losses of nutrient capital. We also found significant compositional differences among those families that occur frequently in both peat and kerangas plots. Despite this, family-level measures of tree diversity and structural characteristics, including tree abundance and stand basal area, did not differ between forest types. Similarly, leaf and litter functional traits and nutrient resorption were invariant across forest types, indicating low plasticity of leaf characteristics associated with plant nutrition. This suggests that belowground carbon accumulation in peatlands is disconnected from aboveground plant community characteristics and is likely driven by belowground processes.

The black walnut Juglans neotropica is a forest species characterized by being a monoecious and deciduous tree with a long life. This species has great ecological, environmental, and economic value, playing a fundamental role in the ecosystem. According to the IUCN, J. neotropica is threatened by anthropogenic activities that have drastically affected its distribution. In this study, the plastid intergenic spacer marker trnS-trnfM was amplified from 74 J. neotropica samples from eight locations in Amazonas region (Peru) to determine its haplotype network, genetic diversity, and genetic divergence. The results revealed that J. neotropica from Amazonas region showed i) a lineage composed of the eight populations embedded into the Rhysocaryon section; ii) three genetic groups within the haplotype network with the presence of an ancestral haplotype (H1) and possibly candidates for new taxa; iii) a high divergence between the populations of Molinopampa and Luya (1.62–2.64% of p-distance); iv) populations with high genetic diversity indices (Levanto = 0.32, Molinopampa = 0.41) with constant threats from anthropogenic activities; and v) high genetic structuring within populations (Fst = 0.04). Overall, these results collectively support a scenario of high variability with limited interpopulation genetic exchange. Our findings provide previously unavailable insights into the vulnerability of the black walnut J. neotropica by (i) quantifying the genetic consequences of human-induced habitat fragmentation and (ii) establishing baseline diversity metrics for future monitoring. These results directly inform in situ conservation priorities by identifying populations harbouring unique alleles that warrant immediate protection. Finally, further research should include nuclear markers (e.g., microsatellites or RAD-seq) to support our findings.

Pinanga represents one of the largest genera of palms and has been extensively collected by botanists, though ecological studies on Pinanga remain limited. We evaluated species diversity and assemblages of Pinanga palms in two contrasting forest types, heath forest (HF) and mixed Dipterocarp forest (MDF) in Brunei Darussalam located in the Borneo biodiversity hotspot. At three HF and three MDF sites, all Pinanga palms greater than 5 cm height within a 3-ha sampling area per site were recorded and taxonomically identified. Selected soil properties (total N and P concentrations, pH, gravimetric water content [GWC] and OM) and environmental variables (litter depth [LD], humidity, canopy openness [CO] and elevation) were determined for each study site. Our survey recorded a total of ten Pinanga species, comprising 981 individuals. Pinanga abundance was significantly higher in HF sites than in MDF sites, while Pinanga abundance and species richness significantly varied between sites. Patterns in Pinanga species assemblages were significantly influenced by soil properties and elevation in the MDF sites but were only influenced by CO and LD in the HF sites. We identified three Pinanga species found in both forest types: Pinanga lepidota, Pinanga salicifolia and Pinanga mirabilis, while seven Pinanga species were exclusive to MDF sites and none were exclusive to HF sites. Two Pinanga species (Pinanga chaiana and Pinanga veitchii) were recorded as singletons and thus are in urgent need of protection. The restricted distributions of these Pinanga species within Borneo signifies a need to tailor specific conservation strategies in their native habitats to avoid their local extinction.

Climbing aroids, despite their abundance in tropical forests, remain underexplored. This study is focused on species richness, abundance, density, and distribution patterns of climbing aroid community in a lowland rainforest in Los Tuxtlas, Veracruz, Mexico. Over two years, two censuses were conducted across 14 plots, recording 12 aroid species from five genera and their potential hosts. Ontogenetic classes were defined and validated, showing a positive correlation between total plant length/apex height and ontogenetic stage, indicating distinct growth phases. Host size (DBH) was significant predictor of the establishment probability across ontogenetic classes. Vertical distribution varied significantly among species, ranging from Philodendron hederaceum (7 m) to Anthurium flexile (0.88 m), with some species predominantly distributed on specific host sizes. Tree falls impacted specific species. Although limitations, including a short study period, restrict broader generalizations, this research establishes a foundational understanding of climbing aroid ecology and underscores the need for standardized methods and long-term monitoring to elucidate their population dynamics and ecological strategies.

Resource partitioning remains a central ecological issue for understanding the structures of animal communities. As members of the generalist New World Thraupidae bird family, tanagers can help reinforce knowledge of animal communities. Thus, to study bird trophic ecology and relationships, I followed six tanager species (Schistochlamys ruficapillus, Tangara desmaresti, Stilpnia cayana, Stephanophorus diadematus, Thraupis sayaca and Dacnis cayana) from the Ibitipoca State Park, south-eastern Brazil, for 12 months. I expected 1) more similarities among frugivorous behaviours when compared to the similarities in the frugivorous diet, 2) no differences between the predation behaviours on arthropods against the use of substrates to capture them, 3) no specialisation in the bird–fruit seed dispersal network and 4) similarities of frugivorous diet and substrate use equal those expected by chance due to the absence of specialisation in frugivory and limited use of substrates. Several ecological and behavioural factors seemed to determine the ways in which Ibitipoca tanagers consumed fruits to reduce similarities in diets and reveal network specialisation. On the other hand, the analysis of predation behaviour indicated that tanager species used similar tactics to reach arthropods randomly on substrates. In general, frugivory seems to be more relevant in trophic partitioning than foraging on arthropods in Ibitipoca tanagers.

Plant-soil microbial interactions play a central role in maintaining biodiversity and coexistence in terrestrial ecosystems. However, to what extent plant-soil feedbacks (PSFs) operate in tropical Afromontane forests remains unclear. In this study, we conducted a PSF shade house experiment using six tree species exhibiting diverse life-history strategies and abundances in a sub-tropical montane forest in Nigeria. Seedlings were grown under controlled conditions in sterilised soil with or without soil inoculum collected under mature trees of each of the six species. We assessed whether conspecific tree seedlings’ performance was altered in comparison to heterospecific seedlings when grown in the soil of their adult trees. Seedling growth did not significantly differ between inocula from conspecific and heterospecific adults in five of the six species tested, indicating no evidence of PSFs. In Garcinia smeathmannii, we found a significant increase in seedling growth when grown in conspecific soil inocula. Given that no PSFs were observed in five out of six species, our study suggests that PSFs may play a limited role in the performance of some species in this Afromontane ecosystem. Nonetheless, the facilitative interaction noted in Garcinia smeathmannii indicates a nuanced ecological dynamic worth further exploration.

Heath forests, or known locally as kerangas, in Indonesia and Malaysia form a distinct and understudied ecoregion. We document the distribution and ecological significance of the largest extent of kerangas in Kalimantan, Indonesian Borneo. We mapped 16,586 km2 of kerangas to the nearest one square kilometre across Kalimantan, showing a significant reduction from previous estimates. About 19% of this area exists as a poorly documented mosaic landscape in Central Kalimantan’s Rungan-Kahayan region. Here, peat-based forests transition to heath and dipterocarp forests, making it difficult to reliably classify these forests for conservation planning. Using remote sensing and tree plot data, we identified three forest types—kerangas, low pole, and mixed swamp. Vegetation structure is influenced by soil, topography, and hydrology, while peat depth and elevation affect species diversity. Our findings indicate that these forests are dynamic ecosystems with diverse vegetation communities adapted to peat as well as sandy soils. Lowland heath forests in Rungan-Kahayan exhibits higher tree densities compared to other Bornean heath forests, reflecting unique ecological adaptations to challenging environments. Despite covering just 3% of Kalimantan’s forest area, these ecosystems remain largely unprotected, facing threats from land conversion and fire. Our study highlights the ecological complexity of kerangas and underscores the urgent need for targeted conservation and further research on these forests.

Soil respiration is the second largest natural flux of Carbon (C) between terrestrial ecosystems and the atmosphere, with tropical forests amongst the largest contributors to such soil-derived C effluxes. With climate change expected to drive changes in both temperature and rainfall, our ability to predict responses of the C cycle in the future hinges upon an understanding of how these factors influence soil respiration. However, these relationships remain poorly characterised across the seasonal tropics, especially South Asia. Here, for two seasonal tropical sites in the Western Ghats of India, we characterised annual, seasonal and temporal variation in soil respiration and assessed its temperature and moisture sensitivity over six years. At both sites, soil respiration was positively correlated with temperature at the instantaneous scale, but showed no relationship with temperature at seasonal or annual scales. In contrast, soil respiration showed significant relationships with rainfall and soil moisture at all temporal scales. At the annual scale, soil respiration was negatively correlated with total annual rainfall. At the seasonal scale, wet season Rs was significantly lower than in the dry season. At the instantaneous scale, Rs showed a parabolic relationship with soil moisture, where soil respiration increased with soil moisture up to ∼21 cm3cm-3 and decreased beyond that point. Our results suggest that future changes in the Indian summer monsoon, especially the frequency and intensity of extreme rainfall events, are likely to significantly impact soil respiration rates in this seasonal tropical forest.