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.

This study provides a community-level analysis of how regeneration requirement and adult stature are related to tree allometry (diameter, height and crown size) throughout post-seedling ontogeny on Barro Colorado Island, Panama. Comparing 65 species, gap species are taller, have higher diameter growth rates and occupy more low-canopy sites (≤10 m canopy height) than shade species at small diameters (≤10 cm dbh). For trees >10 cm dbh, diameter-height relationships and growth rates no longer differ between gap and shade species, but shade species have larger, particularly deeper, crowns than gap species. Species with tall adult stature have more slender stems with larger crowns compared with treelet and mid-canopy species starting at 5 cm dbh. From 10 to 40 cm dbh, diameter growth rate is also significantly greater for tall species. The consistent allometric differences between functional groups on a community level will, in part, determine vertical and horizontal stand structure.

We investigated the dispersal of a large-seeded tree species, Canarium euphyllum (Burseraceae), in the moist evergreen forests of the Khao Yai National Park in Thailand. By combining direct observations of fruit consumption in tree canopies (543 h) and the camera-trapping observations of fallen fruit consumption on the forest floor (175 camera-days), we identified the frugivore assemblage that foraged on the fruits of C. euphyllum and assessed their role in seed dispersal and seed predation. In the canopy, our results showed that seeds were dispersed by a limited set of frugivores, one pigeon and four hornbill species, and predated by two species of squirrel. On the forest floor, seven mammal species consumed fallen fruits. A combination of high rates of fruit removal and short visiting times of mountain imperial pigeons (Ducula badia) and hornbills (Buceros bicornis, Aceros undulatus, Anorrhinus austeni and Anthracoceros albirostris) led us to conclude that these large frugivorous birds provide effective seed dispersal for this tree species, in terms of quantity. These frugivorous species often have low tolerance to negative human impacts and loss of these dispersers would have severe deleterious consequences for the successful regeneration of C. euphyllum.

We investigated the association between lianas and Bertholletia excelsa (Brazil nut), a long-lived, emergent tree of significant ecological and economic importance in Amazonia. Our objectives were: (1) to determine the relationship between crown liana load and liana number, basal area, and origin in relation to the B. excelsa host; and (2) to determine the relationship between liana load and B. excelsa fruit and nut production, diameter growth, and crown form, position and area. One hundred and forty trees (≥50 cm dbh) were selected with representatives of 10 diameter classes and four liana load categories. To quantify fruit and nut production, fruit counts and nut fresh weights per tree were measured in 2002 and 2003, and annual diameter growth was quantified using dendrometer bands. Trees with lianas produced significantly fewer fruits and had reduced nut fresh weights than liana-free trees. Trees with the most extensive liana loads (>75% crown coverage) were 10.2 times more likely to have crown forms categorized as less than half-crowns or few branches than trees with reduced liana loads. No statistically significant relationship was found between liana load and tree diameter growth. Results suggest that liana cutting might increase B. excelsa fecundity and commercial nut yields.

Little is known about the change of species-rich tropical insect communities along habitat gradients. Diversity and species richness of geometrid moths were investigated at 15 anthropogenically disturbed sites in a montane area in the Andes of southern Ecuador representing a successional gradient. These plots were compared with six closed-forest understorey sites. We collected a total of 23,720 individuals representing 868 morphospecies. Local diversity increased with forest recovery and decreased with increasing distance to the natural forest. 18.6% of all species were found as unique singletons. The mean proportions of local singletons differed significantly between three succession classes. Forest understorey showed a higher proportion of singletons than early and late successional stages. Ordination of the moth samples showed a clear separation of geometrid ensembles at successional sites vs. the forest understorey sites. Patterns of species turnover were influenced by the degree of habitat openness, and to a lesser extent by elevation. However, faunal differences were not related to geographical distances between the sampling sites. In conclusion, geometrid moth ensembles of regenerating Andean montane forest remain diverse, but change significantly in composition relative to adjacent natural forest, whereas the diversity and composition of the geometrid fauna are far more strongly affected in non-forested habitats and abandoned pastures.

Local species richness and between-site similarity in species composition of parasitoid wasps (Hymenoptera: Ichneumonidae; Pimplinae and Rhyssinae) were correlated with those of four plant groups (pteridophytes, Melastomataceae, Burseraceae and Arecaceae) in a western Amazonian lowland rain forest mosaic. The mosaic structure of the forest was related to variation in soils within the non-inundated terrain. Significant matrix correlation between patterns in parasitoid wasp species composition and plant species composition was found. Most of the overall correlation was due to idiobiont parasitoids of weakly concealed hosts, which attack host larvae and pupae in exposed situations, with two of the four ecologically defined parasitoid groups showing no correlation at all. A positive correlation between the number of plant species and the number of Pimplinae and Rhyssinae species at a site was found when the latter was corrected for collecting effort. Consequently, the degree of floristic difference between sites may be indicative of the difference in species composition of ichneumonids, and the species richness of plants may serve as a predictor of the species richness of parasitoid wasps. Although these results were obtained in a mosaic including structurally and floristically clearly different types of rain forest, the correlation coefficients were relatively low, and the present results lend only weak support to the idea of using plant distributions as indicators of animal distributions.

The temporal impact of clearing trees on litter production, litter decomposition and on C, N and P release through decomposition of litter was examined in the pasture systems of a semi-arid zone of central Queensland. Paired sites for cleared pastures (developed from clearing woodlands) and uncleared (intact woodland) pastures were selected to represent three dominant tree communities of the region i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla, with three different time-since-clearing (5, 11–13 and 33 y) treatments. Yearly litter production was greater at uncleared sites (1732–1948 kg ha−1 y−1 for eucalypt and 2596 kg ha−1 y−1 for acacia communities) compared with cleared sites (1038–1282 kg ha−1 y−1 for eucalypt and 1100 kg ha−1 y−1 for acacia communities averaged over three time-since-clearing treatments). Rates of litter decomposition and of release of C, N and P from decomposing litter were higher at cleared than uncleared sites for all three tree communities. The cleared and uncleared sites did not differ significantly in total amount of C and N released per year since the concentrations of C and N were greater in litter from uncleared sites but the rate of release was less than that at cleared sites. Slow but continuous release of nutrients in eucalypt and acacia woodlands may be an adaptation of these communities to maintain the nutrient cycle and to avoid leaching of nutrients in the nutrient-poor soils of the region.

Nutrient resorption efficiency of woody plants, litterfall and nutrient fluxes were investigated in a burned and an unburned cerrado plot between October 1997 and September 1999. A large experiment (Fire Project, Brasília, Brazil) on the effects of prescribed burnings was initiated in 1992. Cerrado plots were delimited and subjected to different fire regimes. Seasonal trend of litterfall was similar in both plots but the production in the burned plot was 42.2 g m−2 y−1 before the fourth prescribed fire (September 1998) and decreased by 22% 1 y after burning while in the unburned plot it was around 230 gm−2 y−1. Although nutrient concentrations in leaf litter were higher in the burned plot, the nutrient fluxes were 60–80% lower than in the unburned plot. Nutrient use efficiency (ecosystem level) was 4373 for P and 137 for N. Measured resorption efficiency for 10 cerrado species ranged from 14.5 to 37.2% for N and from 40 to 70.4% for P and in general, there were no differences between plots. N is in short supply, partly because of fire history, but the results, both at ecosystem and species levels (mean N/P in fresh leaves was 18), indicated a stronger limitation by P than by N.

The effects of N, P, NP and NPKS application on plant growth, above-ground primary production and N and P accumulation in the above-ground biomass of a flooded savanna were assessed over two growth cycles. Application of N or P did not improve plant growth and primary production, addition of NP had a noticeable effect, whereas NPKS fertilization led to a three-fold increase in plant production. The four most important grasses in the analysed ecosystem responded to nutrient application with increasing growth, indicating that they all are constrained by nutrient availability, but each species exhibited a different seasonal growth pattern suggesting a temporal division of nutrient resources. N accumulated in the harvested biomass during the growth season was 50% above that of control plants when NP was applied and showed a four-fold increase when NPKS was added. With NP addition, in 2 mo plants accumulated three times more P in the harvested biomass than the control plants. The maximum N accumulated during the growth season in the NPKS treatment represented half the fertilizer N, and probably all the N added (15 g m−2) may have been used if the whole biomass had been considered. With the rather small amounts of P added to the soil in the P treatment (2 g m−2), the maximum amount of P accumulated after 2 mo scarcely represented 13% of the added P, suggesting that most of the fertilizer P became rapidly immobilized or sorbed, not being available to plants in the short term. However, the increasing growth rates of grasses during the following 7 mo indicate that some P fluxed from these pools to the soil solution and to plants.

We studied oribatid (Acari: Oribatida) communities in two distinct microhabitats (litter and root) of the bird's nest fern (Asplenium nidus) in an approximately 4-ha area in a subtropical forest, Okinawa, Japan. We collected a total of 15 729 oribatid mites from 37 ferns and examined whether the size and height of the ferns and the distance between ferns affected the structure of the oribatid communities in terms of the species composition, number of individuals, density (individuals per 100 g dry wt of substrate), number of species and species diversity (Simpson's index). Oribatid communities differed significantly in species composition and density between litter and root components and were evenly distributed horizontally throughout the plot. The density of oribatid mites in the litter decreased significantly with increasing height of the ferns, and the species composition and the numbers of individuals and species in the litter were affected by fern size. Our results suggest that the litter and root of bird's nest ferns allowed diverse oribatid communities to become established, and variations in size and height of the ferns may help to maintain or enhance the diversity of oribatid communities in bird's nest ferns in subtropical forests.

Light is a key environmental factor limiting growth and survival of trees in the subcanopy of wet tropical forests (Davies 2001, Thomas 1996). Light availability varies both vertically and horizontally and affects tree height, crown shape and tree architecture (Bongers & Sterck 1998, Sterck & Bongers 2001, Sterck et al. 1999) in addition to growth and survival (Clark & Clark 1992, 2001). Although many studies of tree seedlings and saplings have shown that growth varies significantly with light availability in tropical wet forests (Clark et al. 1993, Iriarte & Chazdon 2005, King 1991, Kohyama 1991, Montgomery & Chazdon 2002, Oberbauer et al. 1988, 1993; Poorter & Werger 1999, Sterck et al. 1999, Welden et al. 1991), few studies have examined these relationships in size classes above 5 cm dbh (Sterck 1999). King et al. (2005) found that annual increment growth of trees in the 8–20-cm dbh size class in two Asian forests was positively dependent on an index of crown light interception, but no direct measurements of light availability were taken in this study. Due to logistical challenges, few direct measurements of light environments above tree crowns have been made in tropical forests (Sterck & Bongers 2001). To our knowledge, no measurements have been made in second-growth forests.

The crab-eating fox (Cerdocyon thous (Linnaeus, 1766)) and the raccoon (Procyon cancrivorus (Cuvier, 1798)) are medium-sized nocturnal carnivores (3–8 kg) belonging, respectively, to families Canidae and Procyonidae (Berta 1982, Langguth 1975, Yanosky & Mercolli 1993). Both are widely distributed over the Neotropical Region (Colombia, Venezuela, Guyana, Surinam, French Guiana, Paraguay, Uruguay, northern Argentina and the greater part of Brazil) (Berta 1982, Brady 1979, Langguth 1975, Santos & Hartz 1999), being sympatric over most of their range. In Brazil both species are found in various different habitats, including the coastal plains (restingas) (Berta 1987, Langguth 1975, Motta-Junior et al. 1994, Novaes 2002, Santos & Hartz 1999, Wang & Sampaio 2001).

Fire is a common feature of tropical savannas and it has an important role in the ecology and evolution of the flora. Many woody species in tropical savannas are well adapted to fire and have a vigorous resprouting ability that enables them to survive recurring fire (Frost & Robertson 1987, Hoffmann & Solbrig 2003, Meyer et al. 2005). Studies on the interaction between fire and woody plants in Mediterranean-climate regions have considerably increased our understanding of the subject but relationships between plant attributes (stem diameter and height) and post-fire resprouting ability of southern African savanna woody species are poorly understood. Resprouting is a widespread mechanism by which many plants regenerate after partial or total defoliation (Bellingham & Sparrow 2000, Bond & Midgley 2001).