Species of Miconia are considered keystone plant resources for frugivorous birds in Neotropical forests, but for other ecosystems little of their ecological role is known. The fruiting phenology and the composition of frugivores of four Miconia species in savanna and palm swamp from the Brazilian Neotropical savanna were studied in three sites from November 2005 to May 2011. The hypothesis tested was that plants from different habitats share their frugivores and consequently promote links between habitats. Through focal plant observations (30–50 h per species in each site), 668 visits by 47 species of birds were recorded and plants from different habitats shared most of the frugivores (49–97%). The fruiting of Miconia chamissois in the palm swamp during the period of fruit scarcity (dry season) was accompanied by an enhancement in the frugivore bird richness and abundance in this habitat, providing indirect evidence of resource tracking. Bird species which primarily dwell in savanna recorded consuming fruits in palm swamps during the resource-scarce season is taken as evidence of landscape supplementation. Miconia assemblage studied here seems to promote a link between two adjacent habitats in the Neotropical savanna from Central Brazil, a link which is likely to be common in this naturally patchy ecosystem.

The sources of food and the width and overlap of the food niches of Bombus atratus and Bombus morio were determined by field observations and analysis of the pollen loads carried to the colonies by worker bees. The two species together utilized 50 flower species of which 26 were used by both. Solatium paniculatum (Solanaceae) and Psidium guajava (Myrtaceae) were the most frequently visited plants.

The food niche width and niche evenness for both species were similar. The correlation between niche width and niche evenness was non-significant showing that evenness does not depend on niche width. In addition, there was no correlation between niche width and overlap, i.e. overlap varied independently of niche width. A high overlap of food sources utilized by the two species was observed in September, October and November. This may be explained in one of two ways: (a) if B. atratus and B. morio compete for resources, competition would be more intense during those three months; (b) the convergency of both species to the same plant species (Solatium paniculatum and Psidium guajava) would only result in more intensive competition if resources were limiting. However, at that period of the year resources are abundant, therefore although the values of overlap were high, competition need not have occurred.

Maintenance of high plant diversity in tropical rain forests has been hypothesized to be related to intense seed predation, and studies have shown that the impact of seed-eaters varies according to seed size, forest type and level of disturbance. The hypothesis that seed survival and seedling recruitment depending on seed size, are related to forest type and the intensity of harvesting and stand refinement was therefore tested at Paracou, French Guiana, for three animal-dispersed tree species. Two forest areas, corresponding to two forest types, were selected based on the occurrence of a dominant species, Eperua falcata (Caesalpiniaceae). Two factors were tested: forest type (E. falcata-rich and E. falcata-poor) and level of harvesting (unlogged, low intensity of logging, low intensity of logging and thinning liberation by tree-poison girdling) within each forest type. Overall, there was no effect of species nor of logging treatment within forest type after 6 wk. There was only a significant effect of forest type on seed survival in the large-seeded Carapa procera, a rodent-dispersed species in the Meliaceae. In the two medium-sized seed species, Pradosia cochlearia and Manilkara bidentata, two frugivore-dispersed Sapotaceae, the effect of treatment was overall significant but was also highly variable between plots within treatments. After 1 y, C. procera showed little seedling recruitment due to low seed removal and dispersal, and high seed-seedling predation under all conditions. Neither forest type, nor treatment nested within forest type, affected seedling recruitment in P. cochlearia whereas M. bidentata seedlings were favoured in unlogged conditions at the E. falcata-poor forest type. These results suggest that species characteristics (such as seed size and palatability), or local tree diversity and resources for granivores select for contrasting patterns in tree recruitment between forest type in the rodent-dispersed tree species, and these interact with level of tree harvesting and stand refinement in the other frugivore-dispersed tree species.

Tropical tropical montane cloud forests (TMCFs) cover a small portion of the Earth, yet they are significant biodiversity hotspots and centres of endemism, and they provide important hydrological and biogeochemical functions that affect human livelihoods. Given their fundamental sensitivity to climate, TMCFs also serve as an early warning system for climate change impacts. This paper outlines a new international initiative, CloudNet, that aims to promote integrated research across TMCFs, and introduces a special issue that reviews emerging themes and topics in the ecology of TMCFs, highlighting knowledge gaps and suggesting new directions for research. CloudNet is helping coordinate several new research projects and protocols: (1) a global repository of TMCF data and meta-analyses across multiple sites; (2) a multi-site study of plant functional traits across TMCFs; (3) a multi-site study of decomposition processes across TMCFs; (4) a protocol for standardizing climate data collection across TMCFs. These studies are intended to evaluate the extent to which general patterns emerge, accounting for biogeographic, phylogenetic and environmental differences among sites. Common data collection across TMCFs should also allow better integration across disciplines, such as linking nutrient limitation, seed production and propagule recruitment, and enable cross-site comparisons of how TMCFs respond to drivers of global change, including rising cloud bases, increasing temperatures, altered disturbance regimes, biological invasions and extinction, and changing human land use.

This study was conducted in a woodland savanna in western Venezuela exclosed from grazing and burnt once a year towards the end of the dry season. Mean annual rainfall is 1500 mm, with a strong seasonality.

Two cohorts of seedlings of Andropogon semiberbis were tagged and monitored for up to three years. Several variables such as survivorship, plant size, seedling density, fire damage and distance to the nearest adult were measured or estimated. Two burning experiments to measure survivorship before and after fire, and two seedling-growth experiments to assess competitive interference from adult plants of three grass species were performed.

The highest mortality takes place during the dry season and is due to fire. This decreases as the plants get bigger due to increasing structural complexity of the clump by growth which gives added protection to the meristems. Other mortality factors such as desiccation, uprooting and shading seem to be important during the wet season, when mortality rate is relatively constant. Survivorship during the first year and after three years is strongly correlated to the size attained by the end of the first growing season.

Seedling densities are rather low and do not seem to play any role in survivorship in this population. Adult interference with seedling growth decreases with distance and seems to be due to root competition, although there is a tendency toward increased foliage interference related to the canopy structure of adult plants.

In this study I document the growth rate and age of trees in an old-growth montane Hawaiian wet forest and use these results to evaluate the cyclic succession model for forest dynamics. I used two methods to estimate the age of trees – the crown-class model and radiocarbon dating. Over 6000 trees belonging to eight species were tagged and measured over 7 y on Hawaii Island. Growth rates for the dominant tree (Metrosideros polymorpha) were relatively low (mean = 1.3 mm y−1) and varied with tree size and crown class. 14C-based age estimates for 27 M. polymorpha trees loosely corroborated estimates based on the crown-class method. The oldest tree dated by 14C had a median age of 647 y BP, placing it among the oldest documented angiosperm trees in the northern hemisphere. 14C dating revealed that the upper canopy may be comprised of three distinct age groups of M. polymorpha trees of similar size, with the median age of each group separated by 200–250 y. The high density of large, very old trees in multiple groups is unusual for a tropical forest and indicates that forest development may occur through gap-phase regeneration at a fine scale and stand-level mortality at a coarser scale.

Great apes are considered to be important seed dispersers in palaeotropical habitats due to their large body size (this would be reflected in the amount of foods consumed) and large home ranges (Poulsen et al. 2001, Wrangham et al. 1994). Furthermore, the great apes might process seeds in a way that maintains their viability (Lambert 1999). Previous studies of seed dispersal by great apes have generally taken the form of lists of seeds found in their faeces (Voysey et al. 1999a, Wrangham et al. 1994), effects of passage through their guts on seed germination (Idani 1986, Wrangham et al. 1994), and effects of dispersal location on germination/seedling survival (Gross-Camp & Kaplin 2005, Rogers et al. 1998, Voysey et al. 1999b). In contrast with the richness of reports about aspects of seeds after their dispersal, few studies have investigated the dispersal pattern of seeds. In this study, we report on the estimated distances of seed dispersal by the wild bonobo (Pan paniscus Schwartz), a species of great ape.

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.

Large-scale natural disturbances, such as hurricanes, can have profound effects on animal populations. Nonetheless, generalizations about the effects of disturbance are elusive, and few studies consider long-term responses of a single population or community to multiple large-scale disturbance events. In the last 20 y, two major hurricanes (Hugo and Georges) have struck the island of Puerto Rico. Long-term population trends of 17 species of terrestrial gastropod were evaluated to determine whether gastropods respond to hurricane disturbances in a consistent fashion. Some species increased, some decreased, and some exhibited no simple trend in density or spatial variability following disturbance. In addition, some species responded differently to the two hurricanes with respect to population density, absolute spatial variability, or relative spatial variability. Population responses probably hinge on trade-offs between sensitivity to microclimatic changes and resource availability resulting from the relocation of biomass from the canopy to the forest floor. The historical context within which a hurricane occurs may be as important, or more so, than the intensity of the storm, per se.

Aechmea magdalenae is a terrestrial bromeliad that dominates areas of forest understorey on Barro Colorado Island, Panama. Nocturnal CO2 uptake via crassulacean acid metabolism was the primary means of carbon gain under well-watered conditions and all light regimes. The ability to maintain a positive carbon balance under conditions of very low light was demonstrated by laboratory measurements of photosynthesis and forest measurements of growth. Low-light-grown juvenile rosettes had the same daily net assimilation whether tested at photon flux densities of 15 or 300 μmol m−2 s−1 Growth rates of rosettes in treefall gaps were similar to those of plants in closed canopy forest. Growth rates of forest plants were increasingly correlated with canopy openness as the wet season progressed due to increased growth by gap plants, suggesting that water availability rather than light may limit growth during the annual dry season.

The Atlantic forest of Brazil is considered to be a high priority for conservation in South America. Despite its importance, few phenological and ecophysiological data are available for plants of this area. In this study the seasonal changes in the water potentials (Ψ) and the phenological behaviour of three woody legumes are related to environmental conditions, particularly air vapour pressure deficit (VPD). The values of Ψ at predawn were greater than −0.75 MPa for all species even during the dry season (May–September). The minimal daily value of Ψ was −3.8 MPa. The maximum daily amplitude of Ψ (Δ parameter) was correlated with the air vapour pressure deficit, showing high correlation coefficients in linear equations. A high recovery rate of Ψ after rain (greater than 0.80) was registered for all species, suggesting a high hydraulic conductivity. The high values of Ψ at predawn during the year and the strong relationship between the daily amplitude of Ψ and VPD suggested that the changes in the canopy cover are related more to atmospheric drought than to soil water deficit.

Despite the importance of treefall gaps in tropical forest dynamics, few studies have followed gap-phase processes for more than 2 y. We monitored, for five years, the growth and survival of many seedlings of Tetragastris panamensis (Engler) O. Kuntze, Protium panamense (Rose) I. M. Johnston, and Desmopsis panamensis (Rob.) Saff. (three common tree species of the Panamanian tropical moist forest) in artificially created treefall gaps and under intact-canopy control plots. On these same plots, we also monitored light levels using hemispherical photographs taken over an 8-y period. Seedling height growth was faster in gaps than under intact canopies during the first 42 mo of regrowth, then declined to rates similar to those under intact canopies. Light levels in gaps similarly rose and fell, returning to pre-gap levels by month 48. Only Tetragastris panamensis showed higher survival in gaps, contrary to the general assumption that seedling survival is enhanced by gap creation. Our results document important transition points that mark the conclusion of the gap phase, suggesting an estimate of 4y for the duration of the gap phase in this tropical forest.

We studied the effects of savanna fires on the structure of local ungulate communities in a West African woodland savanna. The distribution of 11 ungulate species over 9−15 burned sites (the number of which increased as burning activity continued during the dry season) and 7−13 unburned sites was compared with a variety of null models or randomized ‘virtual communities’. Five different parameters of community structure were examined: body mass distribution, co-occurrence patterns, species richness, species density and guild dominance. Overall, ungulate species were not randomly distributed over burned and unburned sites. The regular spacing of body masses in the set of species recorded on burned and unburned sites indicated competition, since species similar in body mass are more likely to compete than species of different size. However, co-occurrence patterns on burned sites were random, indicating absence of competition at fine spatial scales due to differential habitat use within the burned landscape. Although the attractiveness of the regrowth on burned sites resulted in higher numbers of ungulates compared with unburned sites, species richness was not different. Grazers were the dominant guild on burned sites, but there were no differences in species richness or species density between grazers and browsers on unburned sites.

Features of microhabitats used by tadpoles of 17 anuran species were recorded in 16 streams in the montane meadows of the Serra do Cipó, southeastern Brazil. Month of occurrence of tadpoles, from November 1998 to February 2000 (16 months) was also recorded. The most important ecological features in differentiating tadpole species were position in the water column, time of occurrence and water depth. Tadpole species were then compared based on their microhabitat preferences, and it was tested whether phylogenetically closer species use microhabitats in a more similar way. In hylids, microhabitat use patterns were not influenced by proposed phylogenetic relationships, and many convergences in ecomorphological types may exist. On the other hand, leptodactylids may have undergone a conservative evolutionary history, as they formed a relatively homogeneous group concerning ecomorphological types and microhabitat preferences.

Animals living close to human settlements more often experience disturbance, but also reduced predation risk. Because an escape response is costly, behavioural adjustments of animals in terms of increased tolerance of humans occurs and is often reported in the literature. However, most such studies have been conducted in and around long-existing cities in Europe and North America, on well-established animal populations. Here, we investigate the degree of tolerance of human disturbance across 132 bird species occurring in disturbed (small farms) and undisturbed (intact wetlands and grasslands) areas in Pantanal, Mato Grosso (Brazil), a region with only a very recent history of human-induced disturbance. We found a clear across-species trend toward higher tolerance of human disturbance in birds near farms when compared with birds in wild areas. Such a flexible and perhaps also rapid emergence of tolerance when facing small-scale and very recent human disturbance presumably involves learning and might be attributed to behavioural plasticity. The ability of birds to modify their degree of tolerance of human disturbance may play a key role in the facilitation of wildlife–human coexistence.

Several studies have evaluated the short-term effects of tropical forest fragmentation on plant taxonomic diversity, while only a few have evaluated its effects on functional or phylogenetic diversity. To our knowledge no study has looked at the long-term consequences of tropical forest fragmentation on the three main components of plant diversity simultaneously: taxonomic, functional and phylogenetic diversity. We sampled the vascular flora using belt transects (50 × 4 m) in a continuous tropical semi-evergreen forest (16 transects) and in an adjacent naturally fragmented forest (fragments of 1.7-My-old semi-evergreen forest immersed in a mangrove/sedge matrix) (18 transects), and compared their taxonomic, functional and phylogenetic plant diversity. There were 36 species in the continuous forest and 28 in the fragmented forest. Continuous forest was taxonomically more diverse (25%) than the fragmented forest. All functional diversity metrics were greater (6–33%) in the continuous than in the fragmented forest. Phylogenetic diversity was 19% greater and phylogenetically more overdispersed in the continuous forest than in the fragmented forest. The results suggest that in the fragmented forest not only is taxonomic plant diversity lower, but functional and phylogenetic diversity are as well. The negative effects of forest fragmentation on plant diversity seem to be chronic.

Estimates were made of the populations of seven nests of Macrotermes jeanneli of different sizes in Kenya. Caste and instar composition were examined, and relationships of these to the dimensions of the mound were investigated. Survival of nests of different sizes was followed over four years.

One component of the high organismal diversity of tropical lowland rain forests is the existence of series of closely related, sympatric species. For example, the six distinct tree species of the monophyletic Polyalthia hypoleuca complex regularly grow sympatrically in various combinations throughout the rain forests of Malesia. Theoretical and empirical evidence has been presented indicating that the members of such series either (1) are well differentiated with respect to at least one major niche component; or (2) may lack differentiated niches. In this study, certain sympatric members of the complex are shown to have clearly diverged in autecological characteristics that affect their distribution including: (1) P. glauca, P. hypoleuca, and P. sumatrana differ in growth characteristics, height at maturity, seedling germination requirements, and are found on soils with differing degrees of hydration; (2) P. discolor grows to a different height and on different substrate types than does P. multinervis; and (3) P. glauca and P. hypoleuca seedlings differ in transpiration characteristics and response to flooding and drought.