Anthropogenic wildfires are becoming increasingly frequent in wet tropical forests. This trend follows that of other anthropogenic disturbances, which are now acute and widespread. Fires pose a potentially serious threat to tropical forests. However, little is known about the impact of unintended forest fires on below-ground resources in these ecosystems. This study investigated the influence of fires on the distribution and variability of soil resources on two sets of 50×50-m burned and unburned plots in a Nicaraguan rain forest. Samples were collected at 5-m intervals throughout each plot as well as subsamples at 50-cm intervals. Geostatistical techniques as well as univariate statistics were used to quantify the spatial autocorrelation and variability of selected nutrients (N, P and K), carbon and standing leaf litter. Most variability in this forest was spatially dependent at a scale of 30 m or less. However the average range of autocorrelations varied greatly between properties and sites. Burning altered soil heterogeneity by decreasing the range over which soil properties were autocorrelated. Overall the average patch size (range) for nitrogen was reduced by 7%, phosphorus by 52%, potassium by 60% and carbon by 43%. While phosphorus and leaf litter increased in the burned plots compared to unburned plots, potassium was not different. Nitrogen and carbon did not display a consistent pattern between burning regimes and this may be explained by variation in fire intensity. Leaf litter measurements did not correlate with measured soil nutrients within plots. Observed changes in the burned forest were likely a result of both the intensity of burning and change in vegetative cover between the time of the fires and soil sampling.

Low phosphorus (P) supply frequently has been shown to limit the abundance and activity of nitrogen (N)-fixing organisms, potentially constraining N inputs to ecosystems. Previous research in a montane Hawaiian forest has shown that ground-level P-fertilization led to significant increases in the population size of epiphytic N-fixing lichens (cyanolichens), as well as a shift in community composition from crustose to leafy species. In this study, we ask whether these changes in the cyanolichen community have resulted in increased N inputs to the forest, and also whether the very high levels of P in the canopy of P-fertilized forest stimulate individual lichen fixation rates over those of lichens from a nearby unfertilized reference forest. We used acetylene reduction (AR) assays to measure the fixation rates of 14 cyanolichen species from P-fertilized forest, and calibrated these rates by measuring 15N2 fixation incorporation in four species. We found that the ratio of acetylene reduced to N fixed ranged from 2.4 ± 0.4 in Pseudocyphellaria crocata to 9.3 ± 2.4 in Leptogium denticulatum. Nitrogen fixation rates in the P-fertilized forest ranged from 0.64 ± 0.05 nmol N cm−2 h−1 in Nephroma helveticum to 3.97 ± 1.48 nmol N cm−2 h−1 in Parmeliella nigrocincta. Fixation rates did not vary greatly among species from P-fertilized forest. We compared these P-fertilized rates to those of 10 species from the reference forest, and found that mass-based fixation rates of P-fertilized lichens were not greater than those of lichens from the unfertilized forest. Using the measured AR rates, we estimate that the P additions increase cyanolichen N inputs to the forest 30-fold, from ~0.3 kg N ha−1 y−1 to ~9 kg N ha−1 y−1. These results suggest that P additions to this ecosystem increase N inputs primarily by increasing the abundance of cyanolichens, and that shifts in cyanolichen community composition and changes in individual fixation rate were of lesser importance in determining ecosystem N inputs.

Altitudinal transects of biodiversity are important to understanding macro-ecological patterns. Hump-shaped altitudinal profiles in species richness are a common pattern in terrestrial small-mammal communities studied previously mostly in New World mountain ranges. Based on capture–mark–recapture live-trapping conducted over four seasons (four nights per session) along an altitudinal transect from 1000 to 1747 m asl on the southern slopes of the Soutpansberg Mountains of northern South Africa, we recorded 12 species of small mammal, including nine rodents, two shrews and one elephant shrew (sengi). Three species of rodent and the sengi dominated the communities whilst six species were recorded with three or fewer captures. Although we found no effect of season, we found a significant linear increase in terrestrial small-mammal richness (but not Simpson's diversity, D) with altitude in the Soutpansberg Mountains located just north of the Tropic of Capricorn in South Africa. This trend could best be explained by an increase in the proportion of rocky cover and a change in vegetation from savanna to grassland. Peak densities of three common rodent species and one common insectivore varied from 10 ha−1 (Elephantulus myurus) to 54 ha−1 (Micaelamys namaquensis) and density showed no significant variation with season. However, density either declined (Aethomys ineptus) or increased (Rhabdomys dilectus and Elephantulus myurus) significantly with altitude; this variation was best explained by the proportion of rocky cover. Seasonal variation had a significant effect on body mass of two rodent species. A review of small-mammal studies from major mountain ranges in Africa and Madagascar found that the hump-shaped pattern is not common. Declines in richness with increasing altitude as well as cases of no significant altitudinal change were the most common patterns noted. Tropical African mountains (including the Soutpansberg with 27 species) have far higher small-mammal diversity than temperate African mountains.

We investigated spatial distribution of lianas, and examined relationships between distribution and topography in a secondary forest on the northern part of the main island of Okinawa, south-west Japan. All lianas with a stem diameter exceeding 2 cm at a point 1.3 m from the root were inventoried, and stem diameter and root position were measured within a small watershed (16.0625 ha). Geographical information systems (GIS) were used to divide the watershed into 257 cells in total, each cell being 25 m × 25 m. Three topographic parameters were measured in each cell: slope angle, slope aspect and relief. In total, 930 stems from 20 species of lianas were recorded. Distribution of all liana stems and 14 of 15 species analysed were biased toward concave sites. Abundance of total lianas was higher in concave sites than in convex sites. Our results suggest that distribution and abundance of lianas are strongly affected by topography, and that lianas tend to be distributed in sites with more water and nutrients, which are formed by relief in the Okinawa forest. Factors affecting stem density differed among species.

The fruit of six species of Diospyros (Ebenaceae) provide food for eight species of diurnal primates in the Lopé Reserve, Gabon. Both succulent flesh and immature seeds are eaten but patterns of consumption vary among the primate species. Interactions between D. mannii, which has very large fruit (9 cm × 7 cm) and seeds (5 cm × 2 cm), and primates were observed in detail. D. mannii fruit are unusual, being covered by a dense mat of irritant hairs that are largely retained, but become looser on ripening, when fruit are abscissed. Primates do not eat immature seeds of this species but do predate on seeds of some other Diospyros species. Ripe flesh (and ripe seeds) of D. mannii are eaten by gorillas and chimpanzees but not by monkeys. Comparison of fruit characters and of feeding patterns of primates for the six Diospyros species suggests that large seeds are potentially vulnerable to high levels of predation but the presence of irritant hairs provides protection during fruit development. Abscission of ripe fruit (shown only by D. mannii) appears to afford additional protection from predation on ripe seeds by arboreal monkeys. These observations underline the complexity of plant-animal interactions in tropical forests and suggest that some fruit characters have evolved to reduce seed loss during maturation.

Patterns of bird species diversity within three vegetation types were investigated by the line transect method on Mundanthurai Plateau, South India. Minimum numbers of species and individuals were seen in the study area during July and August. Such seasonal variation was more pronounced in riverine and dry deciduous forest than in the secondary vegetation which was avoided by most of the winter migrants. There was a greater species overlap between riverine and dry deciduous forest than between riverine and secondary vegetation.

No relationship could be established between bird species diversity and tree species/foliage height diversity. The secondary vegetation had fewer specialized forest species and more generalists. Larger birds (>200 g) were rare but smaller ones (<50 g) were more common. The paper emphasizes that the conservation status of avifauna in managed forests in India needs to be assessed and monitored.

Changes in morphological and anatomical leaf characteristics of woody plant species along an altitudinal gradient as well as between a late-successional and mature upper montane rain forest were examined. For leaf size, the Raunkiaer-Webb classification system was applied. The mature-forest transect comprised eight plots of 0.1 ha between 2300 and 3300 m asl, the successional-forest transect, four plots between 2400 and 2750 m asl. The latter comprised structurally heterogeneous vegetation patches. For each plot the proportions of leaf size classes and of the different categories of leaf shape, margin, and apex were calculated. Leaf size and the proportion of drip-tips decreased with increasing elevation. Serrate leaf margins were more prominent at higher elevations. Stomatal density, leaf thickness and related anatomical characteristics did not show significant trends. Differences between the mature and successional forest plots were generally slight. The advanced age of the successional forest probably led to a convergent development of leaf characteristics.

The goal of this study was to assess territoriality and foraging home ranges for stingless bee species; and to develop methods for censusing stingless bee colonies. Colonies of two meliponine bee species, Trigona corvina Cockerell and Trigona amalthea Vachal, were censused using carrion and honey baits. Trigona corvina and Trigona amalthea are dispersed in a Costa Rican tropical wet forest (La Selva) so that foraging ranges of the colonies are non-overlapping. The nest density was c. 0.25 ha−1 for T. amalthea and 1.0 ha−1 for T. corvina. T. corvina visited carrion baits exclusively, while T. amalthea visited both carrion and honey baits. The identities of T. amalthea colonies were confirmed using a nestmate recognition assay. Partamona peckolti Friese, Plebeia frontalis Friese, and T. fulviventris Guerin also appeared at the baits. The reliability of baiting to determine colony abundance and distribution is assessed.

In this study we investigated the importance of two species of fruit bat (Rousettus leschenaulti and Cynopterus sphinx) as seed dispersers for a species of fruit tree (Syzygium oblatum) found in the Xishuangbanna Tropical Botanical Garden in South-West China. We found that although R. leschenaulti and C. sphinx were the two primary seed dispersers of S. oblatum over half of the fruit produced by the tree (65%) fell to the ground. Out of the fruit collected, R. leschenaulti and C. sphinx were able to disperse seeds up to 73 m from the parent tree with the highest density of feeding roosts occurring at 21.3 m (SE = 5.2 m). We found no signs that either species of bat used the parent tree as a feeding roost, instead choosing specific trees that were at lower densities compared with other trees in the forest that were not used. When comparing the viability of seeds in three different habitats (under parent tree, in forest gap, under feeding roost) survival analysis revealed that seedling survival was significantly higher in the forest gap (91.7% ± 4.41%) than under the parent tree (78.3% ± 1.67%), but was not significantly different to seedling survival underneath feeding roosts (86.7 ± 1.67%). Further work also showed that the seeds did not have to be removed from the fruit or ingested by the bat in order to germinate. We conclude that although S. oblatum is not dependent on R. leschenaulti and C. sphinx for successful germination of its seeds, these two species of bat are important seed dispersers and can move seeds to areas where there is a greater chance of germination success and survival.

Two rattans species were studied in Côte d'Ivoire using a stage-classified matrix model to compare their demography and life histories. Respectively 854 and 1009 genets of Eremospatha macrocarpa (pleonanthic) and Laccosperma secundiflorum (hapaxanthic) were censused every 6 mo over 18 mo. The population growth rates of E. macrocarpa (λ = 0.979) and L. secundiflorum (λ = 0.959) were not significantly different from 1. This indicates that the populations were close to equilibrium. However, the difference between the stable stage distributions and the observed distributions indicated temporal variation in vital rates. Elasticity analysis showed that growth and fecundity had lower contributions to λ than the survival rates for the two species. A Life Table Response Experiment revealed that the survival of the first juvenile stage (all stems < 6 m in length), fecundity, growth of the second juvenile stage (at least one stem > 6 m in length) and adult (reproductive) survival highly contribute to the differences between the demography of the two species. Reproduction is postponed longer for L. secundiflorum than for E. macrocarpa and the mean remaining life span for adult genets is shorter for L. secundiflorum than for E. macrocarpa. Finally, our results suggest the existence of two trade-offs within reproduction which suggest that, although the two species have different demographic features, the λ of their populations are not significantly different from 1.

All fig wasps are confined to figs as larvae, and their specialized diets are restricted to fig embryos, galled fig ovaries or other fig wasp larvae (Boucek 1988). Almost all of the ∼800 Ficus species (Moraceae) are involved in species-specific obligate mutualism with a pollinating fig wasp (Hymenoptera: Agaonidae), which also strictly depends on its host fig for reproduction (Berg 2003, Ramirez 1970, Wiebes 1979). More than half of all fig species are functionally dioecious, with male and female functions relegated to separate plants, called gall and seed figs (Kjellberg et al. 1987). Gall figs are functionally male because they foster the pollinator larvae that disperse the fig's pollen as adults. Seed figs are functionally female and produce only seeds. The styles are too long for pollinator ovipositors to reach the ovules, and hence they cannot lay eggs. Gall fig styles are short (Ganeshaiah et al. 1995, Weiblen et al. 1995).

The induction of carbon-based secondary metabolites in leaves following damage has been proposed to be a result of a shift in the carbon:nutrient balance, when growth is limited by nutrients in relation to carbon. Here we test this hypothesis using seedlings of a tropical tree, Shorea leprosula (Dipterocarpaceae). In the short term, we analysed the phenolic content of leaves 7 d after damage on seedlings grown under differing light and nutrient treatments. In the long term, we examined the effect of nutrients, over 12 mo, on leaf phenolic concentration and seedling growth. In both the long and short term, levels of phenolics increased in damaged leaves under low nutrient treatments. No changes in leaf phenolics were detected under high nutrient regimes, or in the short term under low light. In addition, it was found that defoliation of seedlings in high-nutrient environments led to greater rates of leaf production than in undamaged seedlings, suggesting compensation.

Pteridium caudatum is a fern that frequently invades burnt areas in the Yucatán Peninsula and other neotropical sites. While post-fire regeneration of this fern apparently occurs mainly by vegetative means, little is known about the role of its spores in post-fire regeneration and in colonization of newly invaded fields. Central to these questions is whether bracken fern spores maintain their viability after fires. Here we experimentally evaluate the effect of fire-induced temperatures on Pteridium caudatum spore germination. We used 1200-cm3 blocks containing a constant fuel load of 47.4 g of litter, in which we placed spores at three different depths. The blocks were then ignited, and temperatures at each depth were monitored at 1-min intervals for 2 h. One day after the experimental fires, spores were dug out and cultured at 25 °C and 12-h light/dark cycles. Soil temperatures decreased significantly in relation to depth during fires. Spores on the surface were severely affected by fire, while those buried at 1 and 3 cm showed 77% germination. Germination in unburned controls was 86%. Our results suggest that during fires, Pteridium caudatum spores buried a few centimetres below the surface have a high percentage of viability, which could explain the rapid establishment of this species in burnt fields.

A variety of processes have been identified as playing a key role in maintenance of hyper-rich tropical forest, among which ecological sorting caused by niche partitioning challenges stochastic dispersal processes. However, demographic responses to spatio-temporal resource variation that could result in biased species distributions are still little studied. In this paper we investigate from two censuses, c. 15 y apart, of a 12-ha permanent forest sample in French Guiana, how tree recruitment and mortality rates vary among hydrological soil types known to affect species habitat preferences and among ecological guilds related to species light requirement. The results indicate that both recruitment and mortality vary significantly with respect to these factors. While the mean instantaneous mortality and recruitment rates are estimated to 0.98 and 0.81%, respectively, pioneer species, canopy trees and hydromorphic bottomland soils depart significantly from these values. In particular, the pioneers, regenerating either from the soil seed bank or from post-opening seed rain, show faster dynamics than other species. These two guilds harbour probabilities of mortality elevated by a factor of 1.9 and 3.2, respectively, and probabilities of recruitment elevated by a factor of 4.9 and 3.1, respectively. Conversely, canopy trees show slower dynamics, with probabilities of mortality and recruitment lowered by a mean factor of about 0.5 with respect to other species. We also observe that trees growing in hydromorphic bottomlands prove to have significantly higher mortality and recruitment probabilities, by a factor of about 2 with respect to those growing in terra firme.

To understand the variation in community dynamics of tropical montane forests along gradients of soil fertility, death, recruitment and growth of trees (≥5 cm diameter) were monitored over 14 y (1997–2011) in nine plots placed in a matrix of three geological substrate types (Quaternary sediments, Tertiary sedimentary rocks and ultrabasic rocks) and three topographical units (ridge, middle and lower slopes) on Mount Kinabalu, Borneo. The plot area was 0.05 ha for ridge, 0.1 ha for middle slope and 0.2 ha (on ultrabasic rocks) and 1 ha (on the other substrates) for lower slope. Recruitment rates did not show a consistent pattern across geological substrates or topographies. Mortality rates were relatively high in almost all plots during the 1997–1999 period, including the El Niño drought, and in three plots on ultrabasic rocks during 2001–2005. Binomial logistic regression analyses showed that mortality during 1997–1999 increased with soil fertility (soluble phosphorus). Background mortality, excluding these periods, did not differ across geological substrates or topographies. The average growth rate during 1997–2011 was higher on more fertile soils and positively correlated with mortality during 1997–1999. We suggest that a high mortality rate during the drought period was related to high species diversity on more fertile soils, whereas a lower growth rate was related to stunted structures on poorer soils.

The population biology and ecology of most members of the neotropical family Centrolenidae, or glass frogs, are unknown. Glass frogs deposit their eggs in a gelatinous mass on vegetation overhanging streams, the eggs hatch, and the tadpoles drop into the water, where they complete development (Savage 2002). This study will contribute to our limited understanding of centrolenid reproductive ecology by quantifying variation in clutch size, embryonic development and embryonic mortality in a population of Hyalinobatrachium pulveratum.

Performance of seedlings of seven rain forest, canopy dominant Shorea species was studied in a transplant experiment in forest sites at three different elevations (low, mid and high) within the humid zone of southwest Sri Lanka. Five species generally inhabit low- to mid-elevations, one at mid- and lower montane elevations, and one exclusively at lower montane elevations. Temperature, rainfall and cloudiness varied with elevation. For each site seedlings were grown in pots under partial shade conditions using similar soils and evermoist conditions. All growth measures showed differences among elevation sites, among species and in the interaction between species and elevation sites. Performances of species collectively showed (i) decline in height and leaf number with increase in elevation, (ii) higher dry mass at low- and mid-elevation sites compared to that at high-elevation and (iii) a higher mass of single leaves at the mid-elevation site than at the high-elevation site. Rank order of species changed across elevations for both height and dry mass. Dry mass declined with elevation in four of the seven species studied. S. gardneri, the only exclusively lower montane species, increased dry mass with elevation. Height declined with elevation for six of the species with only S. gardneri showing no change. Changes with elevation in the rank order of species for total leaf number and mass of single leaves were small. However, total leaf number and masses of single leaves differed among species and among elevations. S. megistophylla and S. disticha had a few leaves with high individual masses, while S. gardneri, S. affinis and S. trapezifolia had many leaves with less mass per individual leaf. One group of species showed relatively little change in leaf number per seedling and large changes in mass of single leaves. The other group varied more in leaf number but mass of individual leaves remained constant. Growth allocation to leaf production versus individual leaf size appears related to the successional division of Shorea section Doona. Also all species grew better at the low-elevation site irrespective of their natural ranges except S. gardneri, whose natural range is restricted to high elevations, and exhibits markedly lower growth responsiveness than the other wide ranging species.

Interspecific variation in seed size can affect seedling establishment in the light-limited understorey of rain forests. Large seeds with extensive seed reserves may allow seedlings to (1) persist in the deep shade, thereby increasing the likelihood of exposure to a canopy gap (Leishman & Westoby 1994, Saverimuttu & Westoby 1996); (2) promote growth, thereby allowing seedlings to reach higher light strata or to develop sufficient photosynthetic tissue to meet their energy needs in low light (Foster 1986); and (3) allow compensation for tissue losses to herbivores and pathogens (Armstrong & Westoby 1993, Foster 1986, Harms & Dalling 1997). However, comparisons of shade tolerance among species that vary in seed size have produced conflicting results; short-term seedling survival was strongly positively associated with seed size in several studies (Grime & Jeffrey 1965, Leishman & Westoby 1994), but only weakly in others (Augspurger 1984, Grubb & Metcalfe 1996).

Bats are important components in tropical mammal assemblages. Unravelling the mechanisms allowing multiple syntopic bat species to coexist can provide insights into community ecology. However, dietary information on component species of these assemblages is often difficult to obtain. Here we measured stable carbon and nitrogen isotopes in hair samples clipped from the backs of 94 specimens to indirectly examine whether trophic niche differentiation and microhabitat segregation explain the coexistence of 16 bat species at Ankarana, northern Madagascar. The assemblage ranged over 4.4‰ in δ15N and was structured into two trophic levels with phytophagous Pteropodidae as primary consumers (c. 3‰ enriched over plants) and different insectivorous bats as secondary consumers (c. 4‰ enriched over primary consumers). Bat species utilizing different microhabitats formed distinct isotopic clusters (metric analyses of δ13C–δ15N bi-plots), but taxa foraging in the same microhabitat did not show more pronounced trophic differentiation than those occupying different microhabitats. As revealed by multivariate analyses, no discernible feeding competition was found in the local assemblage amongst congeneric species as compared with non-congeners. In contrast to ecological niche theory, but in accordance with studies on New and Old World bat assemblages, competitive interactions appear to be relaxed at Ankarana and not a prevailing structuring force.

To investigate changes in vegetation and climate with altitude, we established forest plots and recorded climatic data at 100-m intervals between 550–1100 m asl on the western slopes of Mount Batilamu, Mount Koroyanitu range, Viti Levu, Fiji. Trees with a dbh ≥10 cm were identified and measured in 21 10 × 10-m plots, starting at 750 m altitude. Temperature and relative humidity sensors were deployed in two habitats, leaf litter and 50 cm above the ground, and two vegetation types, grasslands and forest, at six altitudes over a 48-h period. Two significantly distinct forest types, lowland and montane, were present. Montane forest was found at higher elevations (>950 m asl) and had significantly higher stem density. Mean temperature decreased significantly with altitude and was strongly moderated by vegetation type (lower average and less variation in forest). While average relative humidity significantly increased with altitude, it was strongly moderated by both habitat and vegetation type (higher average and less variation in leaf litter and forest). The lapse rate varied with time of day (higher during the day) and vegetation type (higher in grasslands). Therefore, vegetation and microhabitats create unique microclimates, and this should be considered when investigating current or future climatic patterns along altitudinal gradients on forested mountains.