One of the largest remnants of tropical dry forest is the South American Gran Chaco. A quarter of this biome is in Paraguay, but there have been few studies in the Paraguayan Chaco. The Gran Chaco flora is diverse in structure, function, composition and phenology. Fundamental ecological questions remain in this biome, such as what bioclimatic factors shape the Chaco’s composition, structure and phenology. In this study, we integrated forest inventories from permanent plots with monthly high-resolution NDVI from PlanetScope and historical climate data from WorldClim to identify bioclimatic predictors of forest structure, composition and phenology. We found that bioclimatic variables related to precipitation were correlated with stem density and Pielou evenness index, while temperature-related variables correlated with basal area. The best predictor of forest phenology (NDVI variation) was precipitation lagged by 1 month followed by temperature lagged by 2 months. In the period with most water stress, the phenological response correlates with diversity, height and basal area, showing links with dominance and tree size. Our results indicate that even if the ecology and function of Dry Chaco Forest is characterised by water limitation, temperature has a moderating effect by limiting growth and influencing leaf flush and deciduousness.

Ribbon worms in the genus Balionemertes from Vietnam, the Philippines, Australia, and Guam—as well as Cephalothrix suni from Vietnam—were examined. Our observations indicate that the worms crawl mostly with their ventral surface upwards (the ventral surface being where the mouth opens), a behaviour that has not been documented in previous literature. Like many other worm species with colour patterns, they have a darker-coloured and/or more intensely patterned behavioural dorsal surface (= anatomical ventral surface in Balionemertes and C. suni) than the other side. This type of behavioural dorsoventral body-axis inversion among vermiform benthos seems to be rare—not having hitherto been known at least in the phylum Nemertea—and may be related to their feeding strategy, which should be observed in future studies.

Functional diversity indices have been used to differentiate the relative contribution of stochastic and deterministic processes that modulate the assemblage of communities; however, knowledge regarding the relative contribution of assemblage mechanisms in forest communities is scarce. We analysed the assembly mechanisms driving forest assemblages along a topographic gradient at two spatial scales (1000 m2 and 3000 m2) for three different forest types from subtropical mountain forests (pine-oak, mixed pine-broadleaf and broadleaf forest) in western Mexico, using null models of multi-trait indices. The forest structure differed along the topographic gradient. Upper slopes were dominated by Pinus douglasiana with an importance value index (IVI) of 0.8, while 10 and 13 tree species were required in the middle and lower slopes, respectively, to reach the same IVI. The results support the idea that the subtropical montane forest of western Mexico is a mosaic of communities, when analysed at a scale of 1000 m2 the forest assembly was mainly explained by stochastic processes, while analysis at the scale of 3000 m2 showed that functional convergence of species were the main mechanisms of the assemblage of the pine-oak forest communities due to an abiotic stressful environment.

The estimation of leaf litter turnover is often limited to early-stage decomposition using unrepresentative models and litter types. In tropical secondary forests, particularly exotic-dominated novel forests, the characterisation of litter turnover remains poor. This study estimated the annual turnover of in-situ leaf litter across four forest successional types in Singapore using a Weibull residence time model. Litter turnover and nutrient dynamics diverged between young secondary and old-growth forests. In particular, within novel forests, annual phosphorus return via leaf litterfall was three times that of primary forests, while the mass loss of in-situ leaf litter was highest among all forest successional types, estimated at 92.8% annually with a mean residence time of 176 days, resulting in a litter pool size a third that of primary forests. Our findings suggest that tree species composition and species-specific effects shaped the observed variations in litter turnover and nutrient dynamics across forest successional types and forest stands, whereas tree species richness, canopy structure, soil nutrient levels, and microclimate were found to be non-predictors. Taken together, our study provides an insight into litter turnover in human-modified tropical landscapes increasingly characterised by novel forests, potentially leading to a reduction in surface litter and soil organic carbon pools.

We characterised the soils and vegetation in 15 sets of four quadrats on and around mounds of Macrotermes annandalei (Isoptera, Macrotermitinae) on a plain of deep dystric clay over limestone in Deciduous Dipterocarp Forest in Northern Thailand. Termites have excavated the mounds from the deep calcareous substrate. The mound soils have darker subsoils, larger contents of clays and exchangeable cations, and higher pH values than the surrounding dystric clay loams. The thickets on the mounds are visually different from the surrounding Deciduous Dipterocarp Forest. They have few dipterocarps and are floristically similar to the regionally important Mixed Deciduous Forest. The clear visual differences are confirmed by floristic similarity, cluster, and canonical correspondence analyses for each of the tree, sapling and seedling size classes. The differences between the mound clays and surrounding red clay loams and the associations between soil and forest types are confirmed by ‘t tests’ and the significant correlations of the soil base status with the main floristic axis of the canonical correspondence analyses. Soil variability due to termites and other agents of pedoturbation can significantly contribute to short-range floristic and structural diversity in some dry tropical forests.

Edge effects change biodiversity patterns and ecological processes, particularly in tropical forests. To understand the synergistic impact of multiple edges, this study examines how edge influence (EI) is associated with life-history traits (snout-vent length and body temperature), diversity and microhabitat of amphibians as well as habitat characteristics in a tropical forest in Ecuador. We used EI, a metric that calculates cumulative effects across all nearby edges, in combination with five environmental variables that are part of the amphibians’ microhabitat (temperature, humidity, slope, canopy cover and leaf litter depth) to understand how their biodiversity patterns are impacted. Our results show that most amphibian species tend to be habitat specialists, and many had an affinity for forest edges and warmer habitats. We do not find significant correlations between EI and amphibian life-history traits and diversity. Our findings corroborate previous results that many amphibian species tend to be positively associated with habitat fragmentation and show that this association is likely driven by thermal regulation.

Oceanic islands, due to their evolutionary history and isolation, play a dual role of having high endemicity and being vulnerable to extinctions, with most known extinctions occurring on islands. Plant–animal interactions are particularly important on islands, as island systems generally have low redundancy and are more vulnerable to disruption either via extinction or by invasive species. Here, we examined the fruit removal and seed predation of a keystone palm, Caryota mitis, on Narcondam, a remote oceanic island. The island endemic Narcondam Hornbill (Rhyticeros narcondami) was the sole seed disperser of the palm (90 hours; N = 15 trees), with mean (± SE) visitation rate being 0.23 (± 0.06) individuals per hour and fruit removal rates of 3.5 (± 1.5; range: 0–16) fruits per visit, indicating a lack of redundancy in seed dispersal of the palm on this island. Whereas the invasive rodent, Rattus cf. tiomanicus, was the sole predator of palm seeds (N = 15 individual fruiting palms, 416 trap nights). Overall, 17.1% of the seeds placed (N = 375 seeds) were removed. Seeds placed under and away from the canopy, and at different densities (2 plots with 10 seeds each; 1 plot with 5 seeds, respectively), showed similar removal rates. This indicates density-independent seed predation and the lack of safe regeneration sites for Caryota mitis, with potential deleterious effects on subsequent stages of the ‘seed dispersal cycle’. Here, from a data-deficient site, we provide baseline information on the plant–frugivore interaction of a keystone palm and the potential impacts of an invasive rodent.

Mature leaves of tree seedlings were exposed to high light in four experimental gaps in the Jamaican upper montane rainforest (UMRF). Two of the six species studied were light-demanders: Alchornea latifolia and Clethra occidentalis. Two were gap-favoured: Pittosporum undulatum (an invasive) and Palicourea alpina (a subcanopy shrub). One was intermediate: Hedyosmum arborescens, and one was shade-tolerant: Guarea glabra. After five months, the following significant changes occurred in shade leaves that were exposed to gaps (‘shade-to-gap’ leaves; values as % of those in the pre-gap shade): maximum rate of photosynthesis + 40% (Alchornea), +35% (Clethra), −34% (Pittosporum), +72% (Palicourea); dark respiration +120% (Alchornea), +140% (Clethra), +60% (Pittosporum), +233% (Palicourea), +175% (Hedyosmum), +100% (Guarea); leaf thickness +18% (Alchornea), +18% (Clethra), +14% (Palicourea); leaf mass per unit area +18% (Alchornea), +15% (Pittosporum). Leaves produced in the gaps were (as a percentage of total live leaf number) 74% (Alchornea), 71% (Clethra), 50% (Pittosporum), 71% (Palicourea), 62% (Hedyosmum) and 50% (Guarea). Photosynthetic rates of leaves produced in the gaps were 53–120% higher than ‘shade-to-gap’ leaves. Overall, shade leaves on the three native, more light-demanding species (Alchornea, Clethra and Palicourea) showed photosynthetic acclimation, while the more shade-tolerant species (Hedyosmum and Guarea and Pittosporum undulatum) showed little acclimation in shade-to-gap leaves.

Boswellia papyrifera (Del.) Hochst is a flagship species of semi-arid areas of the East African region with substantial economic, ecological and cultural values. However, its persistence is currently threatened by both anthropogenic and natural pressures. This calls for an immediate conservation action. Planting seedlings of B. papyrifera in natural habitats using nursery-grown seedlings from seed and cuttings has been little successful. Fencing of naturally regenerated seedlings (wildlings) established under the parent trees could be used as an alternative option. The objective of this study was to examine the effect of fencing on the seedling establishment and growth of B. papyrifera wildlings. The experiment was conducted using 36 plots in fenced and open conditions. The results showed that fencing significantly enhances the establishment and growth of B. papyrifera wildlings compared to the open areas. Fenced wildlings exhibited higher survival rates, increased height, greater leaf numbers, larger root collar diameters, larger leaf areas and higher leaf biomass compared to non-fenced wildlings. Therefore, the protection of B. papyrifera seedlings using a fencing intervention can improve the overall establishment and development of B. papyrifera seedlings, thereby contributing to the sustainable conservation and restoration of this valuable species.

We quantified the amount of pollen carried by bats and birds visiting the flowers of cultivated and wild individuals of the endemic Agave cupreata in western Mexico and estimated the distance to which pollen was moved using diurnal/nocturnal inflorescence exclusions and fluorescent powders. There were no differences in the amount of pollen transported by bats and birds near cultivated and wild agaves, but overall, bats transported greater loads than birds. Nocturnal pollen movement was more frequent, and the maximum distance recorded was 630 m (diurnal and nocturnal), with no transfer between cultivated and wild plants. Bats seem to provide a greater pollination service than birds in our focal anthropized landscape. It is necessary to incorporate management practices into mezcal production that ensure enough food for the wide array of animal species using this resource, which in turn will help to maintain the pollination service.

The biodiversity of tropical rainforest is difficult to assess. Yet, its estimation is necessary for conservation purposes, to evaluate our level of knowledge and the risks faced by the forest in relation to global change. Our contribution is to estimate the regional richness of tree species from local but widely spread inventories. We reviewed the methods available, which are nonparametric estimators based on abundance or occurrence data, log-series extrapolation and the universal species–area relationship based on maximum entropy. Appropriate methods depend on the scale considered. Harte’s self-similarity model is suitable at the regional scale, while the log-series extrapolation is not. GuyaDiv is a network of forest plots installed over the whole territory of French Guiana, where trees over 10 cm DBH are identified. We used its information (1315 species censused in 68 one-hectare plots) to estimate the exponent of the species–area relationship, assuming Arrhenius’s power law. We could then extrapolate the number of species from three local, wide inventories (over 2.5 km2). We evaluated the number of tree species around 2200 over the territory.

The study of species association is of great interest in ecology due to its role in understanding key issues such as patterns of habitat use by animals, species coexistence, biotic interactions, and in general factors affecting community structure and assembly. There are many indices that ecologists commonly use, all based on the observed frequencies of organism occurrences, to evaluate the association between a pair of species. However, few of these indices correspond to proper statistical measures of association, and the inferential aspects of their analysis are often overlooked. In this paper, we propose a Bayesian approach based on a simple multinomial-Dirichlet structure to provide a comprehensive inferential framework for any set of association indices. Our approach provides a full statistical analysis for any association index of interest, free of special requirements on the sample size. We illustrate our procedure with a camera-trapping real-dataset, but the analysis of any other dataset of the same type can be readily produced using the R package basa that accompanies this paper.

The studies about the negative effect of epiphytes on their phorophytes show contradictory results and are based on limited variables (e.g., shoot survival). On branches of Bursera copallifera, we experimented with the transplantation/removal of Tillandsia recurvata and artificial tussocks, measuring shoot survival, growth, generation of new shoots, and production of inflorescences and fruits. Most single traits did not differ between treatments. The generation of new shoots was lower in the treatments where T. recurvata was present and increased in the branches where it was removed. The lowest shoot survival was in the treatments where T. recurvata was present or was removed. Removing T. recurvata increased plant relative fitness, and it was 43% lower in branches with T. recurvata. Tillandsia recurvata is a structural parasite of B. copallifera. A negative effect of epiphytes on their phorophytes appears counterintuitive since it would not be evolutionarily stable for an epiphyte to shorten the lifespan of its support. Tillandsia recurvata populations are concentrated on B. copallifera branches between 2-4 cm in diameter, while smaller branches are mostly empty, so it is possible that the negative effect of T. recurvata occurs in the smallest branches, explaining why T. recurvata populations are biased to larger branches.

Fine roots are specialized in nutrient and water acquisition and are critical for species performance and ecosystem functioning. Recent evidence has shown a broad root economic space determined by the orthogonal collaboration and conservation gradients related to resource acquisition and resource conservation, respectively. However, whether these gradients exist among tree species growing in degraded ecosystems where root growth is limited by soil conditions is much an open question. We measured six fine root traits (root diameter, specific root length, root dry matter content, root tissue density, branching intensity, and percentage of arbuscular mycorrhizal colonization) in 11 young tree species growing in sympatry for 9 years in degraded pastures in a tropical dry forest (TDF) in Colombia to determine (1) the covariation between fine root traits and (2) the patterns of belowground niche differentiation among 11 species coexisting under the same soil conditions. The covariation between fine root traits resembled the acquisitive-conservative, but not the collaboration gradient for this degraded habitat. The percentage of mycorrhizal colonization, a critical trait associated with the collaboration gradient, was unrelated to any fine root trait. Furthermore, we found a strong belowground differentiation among species, mainly across root diameter and branching intensity. Our results suggest that compacted degraded soils in TDF landscapes may affect the collaborative association with mycorrhizae, mostly allowing species differentiation along the do-it-yourself gradient. This finding suggests a hypothesis that needs to be tested with more species and sites. We discuss the importance of using root traits to aid species selection for restoration purposes.

CO2 release rates from soils via soil respiration play an important role in the carbon budget of terrestrial ecosystems. Though the roles of soil temperature and moisture on soil respiration are well recognised, less is known about how their effects vary across different land-cover types. This study looked at the interactive effects of land-cover change and microclimate on temporal patterns of soil respiration in a montane forest-grassland-plantation mosaic in a highly diverse but climatically sensitive ecosystem in the tropical Western Ghats of India. Across all vegetation types, soil respiration rates were highest during south-west monsoon (June–October), when root growth, litter decomposition and microbial activity are relatively high and were lowest during the summer. Among vegetation types, soil respiration rates were higher in grasslands compared to non-native pine plantations, whereas that of forest and invasive wattle (Acacia mearnsii) plantations were intermediate between grasslands and pine plantations. The decline in respiration rates following conversion from grasslands to pine plantations could be due to relatively lower microbial activity, soil temperatures and, subsequently, slower litter decomposition. In addition, the sensitivity of soil respiration to changes in temperature and moisture differed between different vegetation types. Across all vegetation types, respiration was largely insensitive to changes in soil temperature when moisture levels were low. However, when soil moisture levels were high, respiration increased with temperature in grassland and wattle patches, decreased in the case of pine plantations and remained largely unchanged in shola forests. Our results suggest that changes in aboveground vegetation type can significantly affect soil C cycling even in the absence of any underlying differences in soil type.

It is well documented that Andean bears (Tremarctos ornatus) feed extensively on plants and carrion, but their hunting habits remain understudied. Better understanding and documentation of Andean bear feeding ecology can improve conservation efforts for this vulnerable species. Here, we report an observation of an Andean bear hunting and capturing a wild guinea pig (Cavia aperea) in Chingaza National Natural Park, in Cundinamarca, Colombia. The sighting occurred in January 2023 by a team of conservationists, and we provided photographic evidence and details of the encounter. Our observation suggests that Andean bears are capable hunters of small rodents, indicating that hunting may play a more important role in the ecology of Andean bears than previously appreciated and highlighting the need for a better understanding of this feeding behaviour.

Climatic conditions have changed within the cloud forests of southern Mexico, but the effects of these changes on tree phenology are not well understood. Our study aimed to determine relationships between seasonal patterns of flowering and fruiting and the annual and long-term changes in temperature and rainfall in El Triunfo Biosphere Reserve, Mexico. Flowering and ripe fruiting intensity and fruit number were recorded for 158 trees of 21 zoochorous species during 17 months in 2019–2021. Circular statistics, synchronization calculations, and generalized linear mixed models were used to determine phenological patterns and relationships between phenophases and temperature, rainfall, and solar radiation. Flowering was most closely associated (negatively) with rainfall, whereas ripe fruiting was positively associated with solar radiation. We compared recent fruiting seasonality with phenological data collected in 1991–1993. The mean date of community fruiting in 2019–2020 was earlier (April 4) than in 1992 (May 1) and 1993 (May 13). Community fruit number in 2020–2021 decreased in comparison to 2019–2020. Our results suggest that decadal trends of increasing minimum daily temperature and an earlier and wetter wet season influenced the timing of community fruiting phenology, and fruit numbers varied greatly between years, possibly impacting resource availability for frugivores in El Triunfo.

Rattus species pose a significant threat to the Philippines, causing substantial economic losses in agriculture and posing health risks to humans. While Ecologically Based Rodent Management (EBRM) has been developed to mitigate rodent outbreaks, its implementation is challenging, particularly in the face of climate and land use changes. In this study, we aimed to potentially enhance EBRM strategies by utilizing a high-performing modelling approach, MaxEnt, to predict the habitat suitability for Rattus species in the Philippines. This study revealed that forested areas exhibit high suitability for R. tanezumi, R. exulans, and R. everetti, with a notable degree of similarities in their habitat suitability. Furthermore, the model predicted that R. argentiventer, a species with no records in the mainland of Luzon, could potentially find suitable habitats in some areas of these regions, particularly in Central Luzon. Conversely, R. norvegicus was predicted to be highly suitable for areas with high-human population density, such as urban cities. The predictive model deepens our understanding of the interactions between Rattus species and their environments across the Philippines, which is crucial for identifying high-risk areas that require immediate intervention. These results have the potential to enhance the EBRM approach more effectively on a national scale. The EBRM strategy based on the predictive outcomes of the MaxEnt model is not only crucial for the Philippines but also serve as a guiding framework for other regions facing similar challenges with rodent populations.

Carbon stocks in root biomass and soil organic carbon (SOC) were analysed in tropical mountain cloud forest (TMCF) of Mexico. Additionally, the hypothesis that the concentration of roots in the forest is not homogeneous but that they are concentrated near the trunks of the trees was evaluated. Root biomass was 707.68 ± 150.41 g·m−2, which stores ∼353.85 ± 75.21 g·C·m−2. Coarse roots contributed 36.8%, fine roots 35.5%, and very fine roots 27.7% of the total biomass. The results did not support the hypothesis that fine roots are concentrated near the trunks of the trees. On average, SOC was 108.23 ± 33.21 Mg·C·ha−1. Mean C stored in the soil (C in roots + SOC) was 111.77 ± 32.97 Mg·C·ha−1. The TMCF is an ecosystem with a high potential for soil carbon storage, with similar C values reported to those in other tropical forests.

The floristic composition of the understory plays a fundamental role in the long-term conservation of the diversity, structure, and function of mountain cloud forests in the Andes. We evaluated the relationship between the understory tree floristic composition of four types of predefined cloud forests and the canopy structure, the light transmitted to the understory, and the effect of topography. Through multivariate analysis, we found an environmental gradient correlated with light penetration into the understory and a gradient associated with the slope and, to a lesser extent, with the elevation. Then, we identified floristically well-differentiated ecological groups in response to environmental conditions; however, the groups only partially coincided with the understory composition of the predefined forests. We found environmental response species groups such as Roupala obovata and Beilschmiedia sulcata that are indicator species of sites with lower light penetration into the understory but with steeper slopes and higher elevation. In comparison, Clusia multiflora and Zanthoxylum quinduense to be the main indicator species from sites with greater light penetration into the understory and lower slope and elevation. These findings support appropriate species selection when implementing restoration strategies in forest landscape restoration plans.