Although the floral traits of Parkia conform to the bat-pollination syndrome, many visitors other than bats have been observed at their flowers. Some chiropterophilous plants are also pollinated by other animals; the syndrome is therefore best regarded as a hypothesis for which field observations and pollination experiments are required. The present study aimed, for the first time, to determine the breeding system of the economically important canopy trees, Parkia speciosa and P. timoriana, and to identify their pollinators. Pollination experiments carried out in Trang and Songkhla Provinces, in 28 trees of P. speciosa and four P. timoriana indicated that they are self incompatible. Open pollination resulted in the highest fruit set (average 60–67% of inflorescences per tree) although this was not significantly different from hand-crossed pollination (48–60%). Insect pollination resulted in fruit set in only 12% of P. speciosa inflorescences. Fruit bats, mainly Eonycteris spelaea, visit flowering plants continuously from dusk till after midnight. Nocturnal and diurnal insects (moths and stingless bees respectively) visit capitula, mostly at the nectar zone. Nectarivorous bats are the most effective pollinator for P. speciosa and P. timoriana. The fact that populations of E. spelaea appear to be declining throughout their distribution is therefore a matter of increasing concern.

Although plant species that attract multiple species of pollinators predominate in tropical plant communities, pollination specialists appear to be at a greater advantage in tropical ecosystems in which pollinators are numerous and many plants flower synchronously. The present study determined the breeding system and legitimate pollinators of Oroxylum indicum Vent. in Songkhla and Patthalung Provinces, Thailand. Oroxylum indicum exhibits steady-state flowering, with one or two flowers per inflorescence opening each night. Flowers open in the evening and drop off shortly after midnight, while its bilabiate stigma is highly sensitive, and quickly close upon being touched. Oroxylum indicum is self-incompatible. Hand-cross pollination and open pollination yielded the highest pollination success (47.7% and 31.2% respectively, n = 7 trees). About 900 pollen grains are needed for initiating fruit set. It is confirmed that a fruit bat, Eonycteris spelaea, is the legitimate pollinator. Bats are responsible for all pollen load and the pollen load from only one visit is generally sufficient to initiate fruit set. Although Eonycteris spelaea is effective, it is an inefficient pollinator. Compared with plant species pollinated by multiple animal species, the likelihood of pollination failure resulting from the decline in populations of Eonycteris spelaea will be much more intense in Oroxylum indicum.

Seed dispersal and predation by spiny rats (Proechimys semispinosus) and red-tailed squirrels (Sciurus granatensis) were studied in five forest gaps and adjacent forest understorey on Barro Colorado Island, Panama, during June and July 2003 and January 2004. Live trapping on grids was used to estimate the abundances of rats in both habitats and was conducted during 10 nights at the beginning of each field season. We captured 70 individual spiny rats (53 in forest gaps and 17 in understorey). To address the removal and dispersal of seeds, semi-permeable wire-mesh exclosures were set at randomly selected stations within the trapping grids. These exclosures allowed the entry of spiny rats, squirrels, and other small rodents but excluded larger granivorous mammals. Seeds were marked with pieces of string that were dusted with fluorescent powder and tracked at night with an ultraviolet light. A total of 304 seeds was removed (159 in forest gaps and 145 in understorey). Spiny rats removed more seeds from gaps, and squirrels removed more seeds from understorey. Both species dispersed more seeds during the rainy season than during the dry season. Squirrels dispersed seeds farther than did spiny rats. Due to their foraging behaviour and association with gaps, spiny rats may disperse seeds from forest understorey into gaps.

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.

Fish biomass, species richness and composition were compared between upland streams draining two contrasting geological units (Pebas and Tsa) in Colombian Amazonia. Because Pebas sediments reportedly show higher levels of base concentrations than Tsa sediments, we expected that the fish communities from the Pebas streams would show highest biomass and species richness, and that the species composition would vary between the two upland systems. Eight forest streams were sampled in four locations, applying four daily sampling events. Tsa soil samples were comparatively sandy, whereas Pebas soil samples tended to be siltier, with higher levels of exchangeable acidity, Ca, Mg and total bases. Conductivity, concentrations of bases (Ca, Mg, K and Na), bicarbonates and temperature showed higher values in Pebas stream-water samples than in Tsa. In total, 7696 fish individuals were captured, belonging to eight orders, 28 families and 122 species. Pebas streams had 1.3 times more species than Tsa streams, and more than twice the total biomass. Species richness and biomass were highly correlated with conductivity and water concentrations of Mg and Na, and biomass alone with dissolved oxygen. Fish species composition differed significantly between the geological units. Species turnover was not related to distance between sampling locations.

In tropical forests, trees compete not only with other trees, but also with lianas, which may limit tree growth and regeneration. Liana effects may depend on the availability of above- and below-ground resources and differ between tree species. We conducted a shade house experiment to test the effect of light (4% and 35% full sun, using neutral-density screen) on the competitive interactions between seedlings of one liana (Byttneria grandifolia) and three tree species (two shade-tolerant trees, Litsea dilleniifolia and Pometia tomentosa, and one light-demanding tree, Bauhinia variegata) and to evaluate the contribution of both above- and below-ground competition. Trees were grown in four competition treatments with the liana: no competition, root competition, shoot competition and root and shoot competition. Light strongly affected leaf photosynthetic capacity (light-saturated photosynthetic rate, Pn), growth and most morphological traits of the tree species. Liana-induced competition resulted in reduced Pn, total leaf areas and relative growth rates (RGR) of the three tree species. The relative importance of above- and below-ground competition differed between the two light levels. In low light, RGR of the three tree species was reduced more strongly by shoot competition (23.1–28.7% reduction) than by root competition (5.3–26.4%). In high light, in contrast, root competition rather than shoot competition greatly reduced RGR. Liana competition affected most morphological traits (except for specific leaf area and leaf area ratio of Litsea and Pometia), and differentially altered patterns of biomass allocation in the tree seedlings. These findings suggest that competition from liana seedlings can greatly suppress growth in tree seedlings of both light-demanding and shade-tolerant species and those effects differ with competition type (below- and above-ground) and with irradiance.

The development of metacommunity theory, which suggests that the diversity and composition of communities is influenced by interactions with other communities, has produced new tools for evaluating patterns of community change along environmental gradients. These techniques were used to examine how plant communities changed along elevation gradients in montane tropical forests. Two transects of 0.1-ha vegetation plots were established every 50 m in elevation in the mountains of eastern Puerto Rico. The transects ranged from 300 m to 1000 m asl and 400 m to 900 m. In each plot, all free-standing woody stems greater than 1 cm in diameter at 130 cm in height were marked, measured and identified. Additional data on three similar transects were taken from the literature. The upper or lower boundaries of species ranges were significantly clumped along all five transects. Coherence, a measure of the number of gaps in species distributions, was also significant across all transects, and three transects showed significant, albeit low, nestedness. Four sites had significant species turnover. These results suggest that metacommunity techniques can be useful in searching for patterns of community change present in montane tropical forests.

Spatial distribution patterns and habitat associations of Fagaceae species in a Fagaceae-codominated hill forest in Sumatra were investigated. Ten Fagaceae species believed to be zoochorous (animal-dispersed seed) and five codominant canopy and emergent anemochorous (wind-dispersed seed) species from Anacardiaceae and Dipterocarpaceae were studied. Five Fagaceae species and all codominant anemochorous species were significantly aggregated while the other five Fagaceae species showed a random distribution pattern. The median distance of small saplings from the nearest reproductively mature tree tended to be shorter for aggregated species than spatially random species. This implied that some Fagaceae species dispersed over longer distances than anemochorous species. Relationships between four habitat variables and distribution of the target species were examined with torus-translation tests. Three Quercus and one Lithocarpus species showed positive habitat associations. Two Quercus species aggregated at the preferred habitat, but the others were randomly distributed. Thus tree species with specific habitat preference do not only aggregate at the preferred habitat. The three ridge-specialist Quercus species showed gradual changes in habitat association, which could reflect avoidance of competition among the species. Most of the Lithocarpus species showed little correlation with habitat variables. Coexistence of the three Quercus species partly reflected subtle differences in topographical preferences. Distribution of five of the six Lithocarpus species was unrelated to topography, so other mechanisms must be sought to account for the maintenance of coexistence in this species-rich genus.

Edge effects encompass biotic and abiotic changes resulting from the interaction between two different habitat types (Murcia 1995). Edge habitats are ecologically distinct from patch interiors, and understanding how ecological patterns change near edges is important in understanding landscape-level dynamics such as the impacts of fragmentation (Ries et al. 2004). Abiotic conditions at the forest edge, such as increased wind and solar radiation, increased fluctuations in temperature, and decreased humidity, may affect forest-adapted organisms (Harper et al. 2005, Murcia 1995). So, edges may affect lizards and amphibians due to their physiological needs (Lehtinen et al. 2003, Vallan 2000). Anurans are considered sensitive to environmental changes due to their permeable skin, shell-less eggs and use of land as well as freshwater habitats (Vallan 2000). Changes in vegetation structure and microclimate are likely to be the predominant factor affecting amphibian abundances across edges (Jellinek et al. 2004, Marsh & Pearman 1997, Schaepfer & Gavin 2001, Urbina-Cardona et al. 2006).

Seed predation by native and alien rodents can limit plant recruitment and ultimately affect forest dynamics and composition (Campbell & Atkinson 2002, Côté et al. 2003, Hulme 1998, Sánchez-Cordero & Martínez-Gallardo 1998). Even partial consumption of seeds by predators may affect plant community structure, though its importance is poorly understood (Steele et al. 1993, Vallejo-Marín et al. 2006). Despite consumption of relatively large portions of seeds by herbivores, seeds can retain their ability to germinate if the embryo remains intact (Dalling & Harms 1999, Janzen 1972, Mack 1998). Germination of damaged seeds may be accelerated or prolonged (Karban & Lowenberg 1992, Koptur 1998, Vallejo-Marín et al. 2006). Damage by seed pests also facilitates ageing stress; which manifests as decreased seedling vigour, decreased seed viability, lower germination percentages and slower germination rates (Priestley 1986).

Climate change may increase the intensity of hurricanes (Emanuel 1987, 2003), and thus the size of disturbance in tropical forests. As a consequence, disturbance-specialist plants, such as lianas, may increase in abundance there (Phillips & Gentry 1994). Putz (1984) hypothesized that lianas create larger treefall gaps by connecting trees together and pulling down multiple trees during storms. This positive-feedback cycle may increase the prevalence of lianas in disturbed tropical forests (Schnitzer & Bongers 2002, Schnitzer & Carson 2001). Alternatively, Putz (1984) proposed that lianas tie and stabilize canopies together, resulting in less disturbance. Forest age may determine the role of lianas during disturbance because liana abundance and composition vary through secondary succession (De Walt et al. 2000, Schnitzer et al. 2000). To test the two hypotheses of Putz (1984), we evaluated the effect of liana cutting between forests of different successional ages on tree damage by hurricane Wilma.

Even though the great majority of the biomass and diversity of mammals in tropical forests inhabit the canopy (Eisenberg & Thorington 1973), most knowledge of this group is based on forest-floor samples (Lowman & Moffett 1993). Studies that include trapping efforts in the canopy are becoming increasingly common (Grelle 2003, Lambert et al. 2005, Malcolm 1995, Patton et al. 2000, Vieira & Monteiro-Filho 2003, Voss et al. 2001), but aspects on the ecology of arboreal small mammals still remain poorly understood. Many species of non-flying mammals co-occur in the canopy and, thus, are expected to use niche dimensions differently to permit coexistence (Cameron et al. 1979). Despite the difficulties of access to and in understanding the three-dimensional use of the arboreal strata by the different species (Emmons 1995), some studies have demonstrated that the differential use of the habitat (Cunha & Vieira 2002, Gentile & Fernandez 1999), of food items (Cáceres et al. 2002, Santori et al. 1995) or both (Leite et al. 1996, Mauffrey & Catzeflis 2003), include strategies involved in the division of resources.

A close relationship has been reported between seed size and many different plant traits such as seedling size, relative growth rate, seedling survival, distance of dispersion, colonization and density of seeds in the soil (Coomes & Grubb 2003, Jurado & Westoby 1992, Lahoreau et al. 2006, Saverimuttu & Westoby 1996, Souza & Valio 2001). Although the association of seed size and shade tolerance is unclear (Westoby et al. 1996) some authors have suggested that a larger-seeded species is better able to tolerate low light availability (Foster 1986, Foster & Janson 1985, Leishman & Westoby 1994) by producing a vigorous seedling with a higher ability to withstand predation (Armstrong & Westoby 1993, Foster 1986) and delaying the beginning of carbon fixation so as to increase survival under a canopy and under leaf litter.

Philornis is a neotropical, monophyletic genus of Muscidae (Diptera) (Couri et al. 2007) that includes many bird parasites (Skidmore 1985). The interaction system of Philornis and birds is very peculiar: fly adults are free-living and only larvae interact with birds (Couri 1985, 1999; Dodge 1963). Larval trophic habits are known for 22 of the 49 species (de Carvalho et al. 2005) and are divided into three groups: coprophagous (P. aitkeni and P. rufoscutellaris), free-living haematophagous (P. falsificus) and subcutaneous (18 spp.). Philornis downsi is unusual because the first and the early second instars display a subcutaneous phase, whereas the late second and third phases show a nest-dwelling haematophagous phase (Fessl et al. 2006).