Seasonally dry tropical forests (SDTFs) stand out by the diversity of phenological patterns used by plants to deal with dry periods. Although the predominant phenological pattern is dry deciduousness, in Mesoamerican SDTFs the heliophilous tree species Bonellia (formerly Jacquinia) nervosa displays an unusual inverted leaf phenology, producing and holding leaves through the dry season while becoming deciduous in the rainy season. Applying a dry season irrigation field experiment (no water, low watering, high watering), we studied the consequences of contrasting water availability from a phenological plasticity response perspective. Contrary to our expectations, our results show no effect of irrigation treatment on leaf phenology. In addition, mid-day twig water potential showed no significant differences across treatments, but reproductive phenological responses varied among treatments: canopy flowering per cent decreased gradually until the beginning of the wet season in all treatments; meanwhile canopy fruit per cent showed a significant decline under low irrigation. Finally, non-structural carbohydrate concentration (starch) was significantly higher in the high irrigation treatment. Our results showed that inverted leaf phenology remains unaffected regardless of supplemental water availability, and suggest a reallocation of non-structural carbohydrates to fruits and seeds in high-irrigation treatments. Given the current and expected increase in extreme drought events, investigations on the responses of trees of different phenologies, including those of inverted leafing such as Bonellia nervosa, are warranted.

Rodents can be important in seed dispersal through their scatterhoarding behaviour, yet, the seed traits that are most influential in seed removal by Afrotropical scatterhoarding rodents remains unclear. Here, we investigated the effect of seed size and nutrient content of four seed species on the scatterhoarding behaviour of rodents in an Afromontane forest, Ngel Nyaki forest, Nigeria. To do this we marked with thread-tags the seeds of Santiria trimera, Beilschmedia mannii, Carapa oreophila and Anthonotha noldeae and observed their fate. We predicted that (1) caching frequency would be higher for larger than smaller seed species; (2) caching frequency would be higher for nutrient-rich than nutrient-poor seeds; (3) larger seeds would be taken across farther distances; and (4) survival of cached seeds would be higher for nutrient-rich seeds. In contrast to studies elsewhere we found no difference in caching probabilities based on seed size, although nutrient-rich (high fat content) seeds had a higher probability of being predated than seeds with lower fat content. Larger and smaller seeds were dispersed over the same distances and nutrient-poor (high fibre content) seeds survived longer in seed caches. Overall, our findings suggest that large, nutrient-rich seed species are less likely to be dispersed by rodents.

Several species of neotropical felines are morphologically and ecologically similar, and are sympatric along large areas of their distribution. This requires mechanisms to allow their coexistence, such as temporal segregation of their activities. The aim of this study was to evaluate the relation between activity patterns of felines and their prey using camera trapping data and their seasonal variation in two tropical environments in south-western Mexico. Excepting Puma concolor, activity patterns for each feline species did not differ significantly between seasons nor between vegetation types. Activity patterns did not differ significantly between species of similar size: mid-sized species had high activity pattern overlaps in the medium forest while large-sized species overlapped to a lesser extent in the cloud forest. Leopardus wiedii differed from large-sized predators in its activity patterns. We recorded a relatively high temporal overlap between felines and their main prey species, particularly in the periods of maximum activity. We found no evidence of temporal segregation between the felines of the Sierra Norte region of Oaxaca and we suggest their coexistence is mediated by the selection of prey with different activity patterns.

Phosphorus uptake by grass species from natural South American grasslands can change depending on root and leaf attributes capable of determining higher, or lower, relative growth rate. The aim of the current study is to investigate whether leaf and root attributes capable of determining leaf and root area production in native C4 grass species Axonopus affinis and Andropogon lateralis are related to higher relative growth rate (RGR), P uptake capacity (maximum P influx; Imax) and concentration. Species grown in 2-litre pots with added nutrition solution were subjected to two treatments, namely 5 μM P l−1 and 30 μM P l−1. Solution aliquots (10 ml) were collected for 30 hours at the end of the study to determine P concentrations. RGR was 3.6 and 2.8 times higher in A. affinis than in A. lateralis in treatments with 5 μM P and 30 μM P. Axonopus affinis recorded the highest P concentration in leaf tissue. This outcome was associated with Imax 85% higher in A. affinis. High RGR was associated with larger leaf and root surface area per dry mass unit, as well as with high P influx capacity and with higher affinity transporters. These species often prevail in areas accounting for greater natural fertility and are more responsive to phosphate fertilization.

Conversion of forest land into different land use types is the primary cause of degradation of land resources, which in turn alters nutrient and carbon cycles, land productivity and diversity of species. There is scarcity of information about land-use changes (LUC) and their effect on relationship of soil quality and species diversity at landscape level in the Vindhyan dry tropical region. We evaluated the impact of land-use changes on soil physicochemical quality and the influence of these qualities on species diversity and organic matter accumulation. We also established the relationship between soil quality indicators and species diversity parameters. To examine impact of LUC, we did a detailed field survey and analysed selected soil quality indicators by standard methods. We examined species diversity parameters and established the relationship between soil quality and species diversity. We found that there is a marked decline in soil porosity, water-holding capacity and soil moisture due to LUC. Conversion from forest land (FL) to savanna land (SL) resulted in soil organic carbon decreasing by ∼40–50%. The decrease was more pronounced in cultivated land (CL) and degraded land (DL) (65–70% and 83–85%, respectively). In the case of total N, maximum decrease in total N of 83–87% was noted in DL as compared with FL. The poor soil quality indicators in degraded and agricultural land can be explained by the interaction between the soil organic carbon and nitrogen loss with diversity loss. This study recommends that for management/restoration of land resources, planning strategies should consider the current landscape structure, with land-use planning.

Disturbances and successional dynamics shape the composition of tree communities, but data remain scarce for tropical forests of West Africa. We assessed the imprint of past disturbances on the composition of evergreen forests in an Ivorian National Park. We hypothesized that (i) Pioneer indices (PI) based on the relative proportion of pioneer and non-pioneer trees relate to changing floristic composition due to successional dynamics, (ii) local community richness peaks at an intermediate value of PI under the Intermediate Disturbance Hypothesis (IDH) and (iii) early successional communities have higher beta diversity due to erratic founder effects. We performed a Correspondence Analysis of tree composition of 38 plots and examined how the main components of floristic variation related to environmental factors and PI. In addition, we tested the relationship between PI, local richness and beta diversity. The variation of PI better explained the main components of floristic variation than abiotic environmental variation, supporting a primary role of successional dynamics in shaping tree communities. We found a peak of richness at intermediate values of PI, supporting the IDH, with a mixture and earlier and later-successional species and more even abundances. The communities were very diverse and included many endemics and rare species. The results underline that the composition of early successional forests greatly varies depending on chance colonization events, while more similar old-growth communities are eventually observed after several decades. The findings should guide management practices for forest restoration, and for conservation of endangered species depending on their successional status.

Oil palm (Elaeis guineensis Jacq) is an economically important crop in South-east Asia, especially in Malaysia and Indonesia. In Malaysia, oil palm is the most profitable commodity in the agriculture sector. The future of oil palm lies in obtaining a higher yield that is aligned and directed towards achieving the Sustainable Development Goals (SDG) by 2030. Elaeidobius kamerunicus was introduced into Malaysia during the late 1980s to boost the production of oil palm fruit bunches. Almost 40 years since the introduction of E. kamerunicus, significant improvements have been witnessed in the increase of oil palm yield. Nevertheless, the current concern in the oil palm sector is regarding the decreasing of fruit set that may be affected by E. kamerunicus. The weevil population plays a crucial factor in the pollination of oil palm. Several factors had been reported to reduce the weevil population such as natural enemies, interaction with local insects, pesticides, climate and male inflorescence. These factors have been addressed in this article based on various studies conducted since the first investigation in Cameroon by Syed in 1977. The role of the pollinator in terms of its biology, behaviour and pollination mechanism is also described in this article, together with the population management of the weevils. This review article will provide a summary of the current state of Elaeidobius kamerunicus in Malaysia and other neighbouring oil palm-producing countries.

In vascular plants, larger seeds are generally associated with higher germination potential, healthier seedlings and overall higher rates of survivorship. How this relationship holds or what other physiological tradeoffs evolved in plants adapted to high-altitude environments, such as the tropical and subtropical highland Polylepis tree, remain unclear. In this study, we evaluated the relationship between seed mass and seedling performance by testing the reserve effect, the metabolic effect, and the seedling-size effect hypotheses in Polylepis tomentella Weddell (Rosaceae). Since the relationship between fitness and seed size can often depend on maternal plant size, we additionally investigated the association between germination success, seedling performance (survival, relative growth rate (RGR) and height), and size of bearing-seed trees under controlled greenhouse conditions. Our results showed that heavier seeds are more likely to germinate, but we did not find evidence that could support the reserve effect, metabolic effect or seedling-size effect. As seedlings from larger and medium seeds exhibited comparatively similar RGR, survival percentages and final size, maternal plant size was positively associated with improved seed quality and seedling performance. These results demonstrate that seed mass and maternal size during early seedling establishment are critical for Polylepis persistence, demography and conservation.

Mangrove species have developed nutrient conservation mechanisms to adapt to oligotrophic intertidal environments. However, nutrient enrichment occurs worldwide, particularly in estuarine and coastal regions. Mangrove species may change their adaptive strategies if nutrient availability increases substantially. To understand how nutrient resorption (a major nutrient conservation strategy) responds to nutrient enrichment, a common mangrove species in China, Aegiceras corniculatum (black mangrove), was selected, and saplings were cultivated in nutrient-enriched soils. After one year, neither N nor P resorption efficiency showed significant variations with nutrient availability and there was no difference between N and P resorption efficiency. Overall, nutrient resorption efficiency of A. corniculatum remained at ∼40%, lower than the global average levels of evergreen plants (∼50%), indicating incomplete resorption of nutrients. Incomplete resorption was also evidenced by the nutrient concentrations, resorption proficiency and N: P ratio of plant leaves. Collectively, these results indicate that black mangrove can maintain constant nutrient resorption efficiency under eutrophic conditions.

Both decreases in compositional similarity with increasing geographic distances between sites (i.e. distance–decay relationship) and vertical stratification of species composition are key issues in ecology. However, the intersection between these two trends has scarcely been investigated. Here we use identical sampling methods in the canopy and at ground level in a tropical rainforest remnant on the coast of the Gulf of Mexico to evaluate, for the first time, a distance–decay relationship within vertical strata in insect assemblages. We found that the ant assemblage was vertically stratified; ant species richness was higher at ground level than in the canopy, and the species composition differed between the two vertical strata. Moreover, we observed that β-diversity increased with geographic distance at ground level, but not in the canopy strata. However, contrary to our prediction, there was less species turnover (lower β-diversity) between vertical strata than between trees. These findings may reflect differences in the dispersal capacity and nest habit of ants from each vertical stratum, and also habitat heterogeneity on the horizontal scale, e.g. the species of sampled trees. Our results illustrate the importance of sampling more than one vertical stratum to understand the spatial distribution patterns of biological diversity in tropical rainforests.

The proliferation of disturbance-adapted species in human-modified landscapes may change the structure of plant communities, but the response of biodiversity to human disturbances remains poorly understood. We examine the proliferation of the palm, Syagrus coronata, in disturbed forest stands and its impacts on the structure of vascular epiphyte assemblages in a human-modified landscape of Brazilian Caatinga dry forest. First, we compared S. coronata density between old-growth and regenerating forest stands. We then surveyed vascular epiphytes on 680 phorophytes (S. coronata and non-palm/control species) across five habitat types with different disturbance levels. There was an eight-fold increase in S. coronata density in regenerating areas compared with in old-growth forest. Syagrus coronota supported richer epiphyte assemblages at local (i.e. per palm) and landscape (i.e. pooling all palms) scale than control phorophytes, supporting more than 11 times the number of species of control phorophytes at both scales. Epiphyte assemblages were more abundant, species-rich and dominated by abiotically dispersed species in forest sites with intermediate disturbance levels (regenerating forest stands). More than simply operating as an exclusive phorophyte for more than 90% of the epiphyte species we recorded here, S. coronata favours epiphyte persistence and structures their assemblages across human-modified landscapes of the Caatinga forest.

The extinction of megafauna may lead to the trophic collapse of ecosystems that depend on the dung that they produce. Some dung beetle species may undergo phenotypic changes in response to altered resource availability. The pronotal width of dung beetles is a trait that can be used as a proxy measure for the amount of dung provisioned during the larval stage. In this study conducted in Peninsular Malaysia, we compare the intraspecific difference in pronotal widths of dung beetles in forests with and without megafauna. Beetles were collected using burrowing interception traps baited with elephant dung. Six species with a minimum sample size of 55 beetles per species were used. Pronotum widths were compared using Bayesian estimation (BEST). There was no credible difference between intraspecific pronotal widths of four species, but credible differences between the mean parameters of two species, Liatongus femoratus and Oniticellus tessellatus. Both these species belong to genera that have a close association with megafauna, while the other are believed to be generalists. This may indicate that species that depend on megafauna dung as a breeding resource undergo a phenotypic change following the loss of their preferred dung type. Phenotypic changes appear to be a pathway which allows species to survive the initial trophic collapse of an ecosystem.

Jackfruit (Artocarpus heterophyllus Lam.) is an exotic invasive plant species in the Brazilian Atlantic Forest that causes changes in the environment through the release of allelopathic substances and has high fruit production. We aimed to understand the potential effects of the jackfruit on the non-volant small mammal assemblage in an area protected by law, in the municipality of Cariacica – Espírito Santo, south-eastern Brazil. We sampled the small mammals assemblage using live traps in 18 sites, eight with jackfruit and 10 without. We ordinated the assemblage and tested possible differences in species richness and abundance according to the jackfruit density. We recorded 31 species of non-volant small mammals, with 13 species endemic to the Atlantic Forest. Jackfruit species can affect both positively and negatively the studied assemblage of non-volant small mammals. For species with a frugivory habit, jackfruit has a positive effect favouring these species. On the other hand, for insectivorous species, jackfruit represents an impact inhibiting the presence of these species in an area with high jackfruit density. The results presented are the first step in understanding the effect of this invasive species on a small mammals assemblage and initiating a monitoring of these species in areas affected by jackfruits. Furthermore, management of jackfruits in this protected area is required.

Understorey wildfires harm tropical forests by affecting natural regeneration, but the trajectories of fire-disturbed forests after disturbance are poorly understood. To fill this gap, we conducted experimental burns in a transitional forest between the Amazon forests and the Brazilian Savanna (Cerrado) and investigated their effects on plant community diversity of regeneration. The experiment consisted of three 50-ha plots that between 2004 and 2010 were burned either annually (six times), every three years (thrice) or not at all (Control). To evaluate early post-fire recovery, we recorded grass occurrence and regenerating stems (≤1 cm in diameter at breast height). We noted that high fire-frequency plots had a reduction of species richness (62%) and abundance (84%) and were associated with floristic and structural changes, dominance of few species and increase of grass colonization when compared with low fire-frequency. We observed that resprouts were the main pathway for forest restoration in both burned regimes, particularly in low fire-frequency. However, the forest can recover from fires by means of resprouting, until a threshold in fire frequency is reached, when resprouts and seedlings declined for most of the species, with a few fire-tolerant species becoming dominant.

While populations of the Endangered Grey Parrot Psittacus erithacus have collapsed across its range, the species remains remarkably abundant on the island of Príncipe, Gulf of Guinea. We examine how aspects of its ecology interplay with local environmental conditions, to inform conservation strategies for this species and other large parrots. On Príncipe, parrots breed in large trees of common species, with nest densities (42 ± 34 km−2) greatly exceeding those for any comparably sized parrot. Productivity is high (1.9 chicks per cavity), probably reflecting the absence of nest competitors and predators. Food sources are abundant and much of the island is inaccessible to trappers, so many nests are successful each year. Historically harvest has involved taking only chicks from trees in a few traditional patches. These conditions have combined to allow Grey Parrots to thrive on Príncipe, while elsewhere nest trees are timber targets, nest competition and nest predation are likely to be more intense, trapping is indiscriminate, and few areas remain unexploited by trappers. Preservation of large trees as breeding refugia, and vigilance against the indiscriminate trapping of adult birds, are identified as key conditions to stabilize and recover mainland Grey Parrot populations and indeed large parrots generally, given their very similar ecological traits and anthropogenic circumstances.

Herbivores use a wide range of factors to choose their host, including their own physiological states, physical characteristics of plants and the degree of competition. Field observations of herbivores in their native habitats provide a means for simultaneously estimating the relative importance of these factors, but statistical analysis of all these factors may be challenging. Here we used a 7-week dataset of leaf-cutting ant (Atta cephalotes) foraging in a diverse Neotropical arboretum containing 193 tree species (822 trees) to examine the relative role of tree phylogeny, territoriality and tree functional characteristics using a phylogenetic generalized least squares (PGLS) model. We observed that 54 tree species (117 trees) were foraged by the ants. This pattern was not random, but reflected known features of leaf-cutting ant foraging behaviour, such as a preference for larger trees and the decreased likelihood of foraging at the periphery of a colony’s territory. However, random effects such as tree phylogeny, the identity of individual trees and colony-specific effects explained most of the variation in foraging data. A significant phylogenetic effect on foraging likelihood (λ = 0.28), together with repeated measures of foraging on the same tree species, allowed estimation of relative palatability for each plant species. PGLS models can be flexibly scaled to include other covariates for even more complex investigation of foraging behaviour, and the link function can be modified to include the amount of plants foraged. As a result, PGLS can be used as a flexible framework for the study of LCA foraging.