A greater relative allocation of phosphorus (P) to photosynthetically active cells functions to maintain a rapid photosynthesis under P limitation, and may be a key mechanism of plants to use P efficiently. This mechanism has not been studied in tropical trees despite the productivity of tropical forests often being limited by P. In this study, the spatial distribution of P among tissues on a cross-section of leaf lamina was analysed for 13 tree species from P-limited sites on Mount Kinabalu, Borneo. Most species showed greater P concentration in palisade mesophyll than in spongy mesophyll and epidermal tissues, suggesting that tropical trees under P limitation localize foliar P in photosynthetic palisade mesophyll.

We compared exotic pasture grass cover near the edges of 20–25-y-old secondary forests (N = 8) with those of mature forests (N = 8), bordering actively grazed pastures on the Pacific Coast of Ecuador. We estimated grass cover in 224 1 × 3-m plots along transects that ran from the pasture edge into forest interiors (11–44 m). Using a spline regression, we divided the transects into three segments: exterior (in the pasture), edge and interior (in the forest). With a stepwise regression, we tested the effect of transect section, forest type and distance from edge on grass cover. Forest type, distance from edge, interior transect section and the combined effect of distance from edge in both the interior and exterior sections explained variation in grass cover. Grass abundance was higher and penetrated further into secondary than mature forests. Edge proximity and differences in forest canopy openness likely favours recruitment and persistence of pasture grasses.

There is still much to learn about pollination ecology in areas of high species diversity, such as the Neotropical region. For example, the role of non-flying mammals in pollination is largely unknown in the Neotropical areas, despite the importance of this group in the pollination of plants in other regions. Here we report evidence for flower visitation by a rodent to Oreocallis grandiflora (Proteaceae) in our study site in the southern Andes of Ecuador. For a period of 241 h, camcorders equipped with infrared lights revealed 22 occurrences of floral visitation by Microryzomys altissimus (Cricetidae) to inflorescences of O. grandiflora. Pollen samples taken from the fur of captured individuals showed that M. altissimus carries pollen of O. grandiflora, indicating a potential pollinator role for the rodent. This is the first record of flower visitation by a rodent in the Neotropical Andes. Pollination interactions between non-flying mammals and Proteaceae have been reported in other southern hemisphere continents. This study underscores the need for more research on pollination interactions in the Neotropics, especially in critical Andean biodiversity hotspots.

Avian predators may represent an important selective pressure favouring the evolution of aposematic colouration in millipedes that present chemical defences. However, the role of their warning colouration in predator avoidance remains poorly explored under field conditions, especially in Neotropical forests. Thus, to evaluate the hypothesis of the predator avoidance, we conducted a factorial experiment utilizing artificial replicas of millipedes constructed from plasticine and placed in the natural habitat of Odontopeltis aleijadinho (Polydesmida, Chelodesmidae), an Atlantic Forest endemic aposematic millipede. We assessed patterns of attack to aposematic and non-aposematic replicas applied with repugnant fluid extracted from living millipedes and two control treatments, distributed as a total of 300 replicas exposed for 48 h on the forest floor. The average percentage of replicas attacked was nearly 10-fold higher on those non-aposematic control replicas (13.3% ± 3.3%) than on aposematic replicas (1.3% ± 0.9%). In 24 replicas attacked by avian predators, no effect of millipede repugnant fluid was found, but the effect of colouration pattern was statistically significant. Our data support the hypothesis that a warning colouration pattern involving yellow spots symmetrically distributed along the millipede body can mediate avian predator avoidance.

Epiphytes represent keystone resources for many arthropod and vertebrate species, however their ecology remains poorly explored, especially within the palaeotropics. Several recent studies have examined relationships between epiphyte richness and characteristics of local habitats, although these have all focused on neotropical forests. Here, we aim to determine whether predictors of neotropical epiphyte richness are consistent at a palaeotropical site. A total of 44 host trees (dbh range 25–288 cm) were sampled at two study sites on Buton Island, Indonesia. For each tree, epiphyte richness and seven variables relating to characteristics of the host tree and surrounding habitats were recorded: site (a proxy value for disturbance level and water availability), host above-ground biomass (agb), altitude, bark texture, exposure, emergence and crown area. Gaussian GLM analyses indicated that the percentage deviance explained in epiphyte richness per host was greatest for agb (20.9%), crown area (19.6%) and site (15.5%); similar to previous findings from the neotropics. Results therefore suggest that high epiphyte diversity within palaeotropical forests is most likely to be found in large tracts of undisturbed forest, supporting large, broad-crowned trees.