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The Anthropocene is a time of unprecedented and accelerating rates of environmental change that includes press (e.g., climate change) and pulse disturbances (e.g., cyclonic storms, land use change) that interact to affect spatiotemporal dynamics in the density, distribution, and biodiversity of organisms. We leverage three decades of spatially explicit data on the density of a tropical folivore (Lamponius portoricensis [Insecta, Phasmida]) in a hurricane-mediated ecosystem (montane rainforest of Puerto Rico), along with associated environmental attributes, to disentangle the effects of interacting disturbances at multiple spatial scales. Spatiotemporal variation in density at a small spatial scale is affected by disturbance-related characteristics (hurricane severity, time after most recent major hurricane, ambient temperature, and understory temperature), legacies of previous land use, and understory habitat structure. Nonetheless, only a small proportion of spatiotemporal variation in density was related to those characteristics. In contrast, the majority of interannual variation in mean density at a larger scale was related to disturbance characteristics and understory habitat structure. These factors combine to affect a weak and declining trend in the density of L. portoricensis over time. The low resistance of L. portoricensis to Hurricane Hugo, as compared to Hurricanes Georges and Maria, likely arose because a drought followed Hurricane Hugo. The disturbance regime of the region is predicted to include increases in ambient temperatures, frequency of high-intensity storms, and frequency of droughts. Such trends may combine to threaten the conservation status of L. portoricensis, and other species with which it shares similar life history characteristics.

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Microbiota perform vital functions for their mammalian hosts, making them potential drivers of host evolution. Understanding effects of environmental factors and host characteristics on the composition and biodiversity of the microbiota may provide novel insights into the origin and maintenance of these symbiotic relationships. Our goals were to (1) characterize biodiversity of oral and rectal microbiota in bats from Puerto Rico; and (2) determine the effects of geographic location and host characteristics on that biodiversity. We collected bats and their microbiota from three sites, and used four metrics (species richness, Shannon diversity, Camargo evenness, Berger-Parker dominance) to characterize biodiversity. We quantified the relative importance of site, host sex, host species-identity, and host foraging-guild on biodiversity of the microbiota. Microbe biodiversity was highly variable among conspecifics. Geographical location exhibited consistent effects, whereas host sex did not. Within each host guild, host species exhibited consistent differences in biodiversity of oral microbiota and of rectal microbiota. Oral microbe biodiversity was indistinguishable between guilds, whereas rectal microbe biodiversity was significantly greater in carnivores than in herbivores. The high intraspecific and spatial variation in microbe biodiversity necessitate a relatively large number of samples to statistically isolate the effects of environmental or host characteristics on the microbiota. Species-specific biodiversity of oral microbiota suggests these communities are structured by direct interactions with the host immune system via epithelial receptors. In contrast, the number of microbial taxa that a host gut supports may be driven by host diet-diversity or composition.

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The Anthropocene is a time of rapid change induced by human activities, including pulse and press disturbances that affect the species composition of local communities and connectivity among them, giving rise to spatiotemporal dynamics at multiple scales. We evaluate effects of global warming and repeated intense hurricanes on gastropod metacommunities in montane tropical rainforests of Puerto Rico for each of 28 consecutive years. Specifically, we quantified metacommunity structure each year; assessed effects of global warming, hurricane-induced disturbance, and secondary succession on interannual variation in metacommunity structure; and evaluated legacies of previous land use on metacommunity structure. Gastropods were sampled annually during a 28-year period characterized by disturbance and succession associated with 3 major hurricanes (Hurricanes Hugo, Georges, and Maria). For each year, we evaluated coherence (the extent to which the environmental distributions of species are uninterrupted along a common latent environmental gradient), species range turnover, and species range boundary clumping; and conducted co-occurrence analyses for each pair of species. We used generalized linear mixed-effects model to evaluate long-term responses of the metacommunity to aspects of global warming and disturbance. Metacommunity structure was remarkably stable, with consistent patterns of species co-occurrence. Disturbance, warming, and successional stage had little effect on metacommunity structure. Despite great temporal variation in environmental conditions, groups of species tracked their niche through space and time to maintain the same general structure. Consequently, metacommunity structure was highly resistant and resilient to multiple disturbances, even those that greatly altered forest structure.

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A number of recent studies have documented long-term declines in abundances of important arthropod groups, primarily in Europe and North America. These declines are generally attributed to habitat loss, but a recent study [B.C. Lister, A. Garcia, Proc. Natl. Acad. Sci. USA 115, E10397-E10406 (2018)] from the Luquillo Experimental Forest (LEF) in Puerto Rico attributed declines to global warming. We analyze arthropod data from the LEF to evaluate long-term trends within the context of hurricane-induced disturbance, secondary succession, and temporal variation in temperature. Our analyses demonstrate that responses to hurricane-induced disturbance and ensuing succession were the primary factors that affected total canopy arthropod abundances on host trees, as well as walkingstick abundance on understory shrubs. Ambient and understory temperatures played secondary roles for particular arthropod species, but populations were just as likely to increase as they were to decrease in abundance with increasing temperature. The LEF is a hurricane-mediated system, with major hurricanes effecting changes in temperature that are larger than those induced thus far by global climate change. To persist, arthropods in the LEF must contend with the considerable variation in abiotic conditions associated with repeated, large-scale, and increasingly frequent pulse disturbances. Consequently, they are likely to be well-adapted to the effects of climate change, at least over the short term. Total abundance of canopy arthropods after Hurricane Maria has risen to levels comparable to the peak after Hurricane Hugo. Although the abundances of some taxa have declined over the 29-y period, others have increased, reflecting species turnover in response to disturbance and secondary succession.

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Fragmentation per se due to human land conversion is a landscape-scale phenomenon. Accordingly, assessment of distributional patterns across a suite of potentially connected communities (i.e. metacommunity structure) is an appropriate approach for understanding the effects of landscape modification and complements the plethora of fragmentation studies that have focused on local community structure. To date, metacommunity structure within human-modified landscapes has been assessed with regard to nestedness along species richness gradients. This is problematic because there is little support that species richness gradients are associated with the factors moulding species distributions. More importantly, many alternative patterns are possible, and different patterns may manifest during different seasons and for different guilds because of variation in resource availability and resource requirements of taxa. We determined the best-fit metacommunity structure of a phyllostomid bat assemblage, frugivore ensemble, and gleaning animalivore ensemble within a human-modified landscape in the Caribbean lowlands of Costa Rica during the dry and wet seasons to elucidate important structuring mechanisms. Furthermore, we identified the landscape characteristics associated with the latent gradient underlying metacommunity structure. We discriminated among multiple metacommunity structures by assessing coherence, range turnover, and boundary clumping of an ordinated site-by-species matrix. We identified the landscape characteristics associated with the latent gradient underlying metacommunity structure via hierarchical partitioning. Metacommunity structure was never nested nor structured along a richness gradient. The phyllostomid assemblage and frugivore ensemble exhibited Gleasonian structure (range turnover along a common gradient) during the dry season and Clementsian structure (range turnover and shared boundaries along a common gradient) during the wet season. Distance between forest patches and forest edge density structured the phyllostomid metacommunity during the dry and wet seasons, respectively. Proportion of pasture and forest patch density structured the frugivore metacommunity during the dry season. Gleaning animalivores exhibited chequerboard structure (mutually exclusive species pairs) during the dry season and random structure during the wet season. Metacommunity structure was likely mediated by differential resource use or interspecific relationships. Furthermore, the interaction between landscape characteristics and seasonal variation in resources resulted in season-specific and guild-specific distributional patterns.

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Research concerning spatial dynamics of biodiversity generally has been limited to considerations of the taxonomic dimension, which is insensitive to interspecific variation in ecological or evolutionary characteristics that play important roles in species assembly and provide linkages to ecosystem services. Consequently, the assumption that the taxonomic dimension is a good surrogate for other dimensions remains unconfirmed. We assessed variation in taxonomic (species richness) as well as phylogenetic and functional (Rao's quadratic entropy, a measurement of dispersion) dimensions of bat biodiversity along an elevational gradient in the Manu Biosphere Reserve of Peru. Phylogenetic dispersion was based on relatedness of species derived from a mammalian supertree. Functional dispersion was estimated separately for each of six functional components that reflect particular niche axes (e.g. diet, foraging strategy, body size) and for all functional components combined. Species richness declined nonlinearly with elevation, whereas phylogenetic dispersion and functional dispersion based on all functional components were not significantly associated with elevation (orthogonal polynomial regression). Moreover, considerable heterogeneity in the form of elevational relationships existed among functional components. After accounting for variation in species richness, dispersion of phylogenetic, diet and foraging strategy attributes were significantly greater than expected at high elevations, whereas dispersion of body size was significantly less than expected at high elevations. Species richness was a poor surrogate for phylogenetic or functional dispersion. Functional dispersion based on multiple components obscured patterns detected by particular components and hindered identification of mechanistic explanations for elevational variation in biodiversity. Variation in phylogenetic dispersion effectively captured the composite variation represented by all functional components, suggesting a phylogenetic signal in functional attributes. Mechanisms that give rise to variation in richness do not fully account for variation in phylogenetic or functional characteristics of assemblages. Greater than expected phylogenetic, diet and foraging strategy dispersion at high elevations were associated with the loss of phylogenetically or functionally redundant species, suggesting that increasing interspecific competition with decreasing productivity resulted in competitive exclusion. In contrast, low dispersion of size attributes at high elevations suggests the importance of abiotic filtering that favours small-sized species that can more easily enter torpor.

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Understanding the effects of disturbance and secondary succession on spatio-temporal patterns in the abundance of species is stymied by a lack of long-term demographic data, especially in response to infrequent and high intensity disturbances, such as hurricanes. Moreover, resistance and resilience to hurricane-induced disturbance may be mediated by legacies of previous land use, although such interactive effects are poorly understood, especially in tropical environments. We address these central issues in disturbance ecology by analyzing an extensive dataset, spanning the impacts of Hurricanes Hugo and Georges, on the abundance of a Neotropical walking stick, Lamponius portoricensis, in tabonuco rainforest of Puerto Rico during the wet and dry seasons from 1991 to 2007. By synthesizing data from two proximate sites in tabonuco forest, we show that resistance to Hurricane Hugo (97% reduction in abundance) was much less than resistance to Hurricane Georges (21% reduction in abundance). Based on a powerful statistical approach (generalized linear mixed-effects models with Poisson error terms), we documented that the temporal trajectories of abundance during secondary succession (i.e., patterns of resilience) differed between hurricanes and among historical land use categories, but that the effects of hurricanes and land use histories were independent of each other. These complex results likely arise because of differences in the intensities of the two hurricanes with respect to microclimatic effects (temperature and moisture) in the forest understory, as well as to time-lags in the response of L. portoricensis to changes in the abundance and distribution of preferred food plants (Piper) in post-hurricane environments.

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Este estudo compara a resposta de uma comunidade aves à exploração madeireira de baixo impacto através da distribuição das espécies em floresta controle e manejada ao longo de cinco anos com amostragem pré e pós-exploração. O procedimento de ordenação mostrou que a similaridade da comunidade de aves após a exploração madeireira foi menor que a similaridade entre as amostras do período de pré-exploração. Além disso, a ordem das abundâncias das 43 espécies mais comuns foi alterada entre o período anterior à exploração e 3 a 4 anos após a exploração na floresta manejada. A exploração afetou as taxas de captura de 20 espécies, diretamente ou através de uma interação com o tempo. Os insetívoros terrícolas e os insetívoros que seguem bandos mistos foram as guildas mais afetadas pela exploração madeireira. Ambas as guildas mostraram declínio, correlacionado com o tempo, em suas abundâncias em floresta manejada. Insetívoros seguidores de formigas e insetívoros arborícolas não apresentaram diferenças entre a floresta manejada e controle, apesar de algumas espécies dessas guildas terem apresentado efeitos relacionados ao manejo florestal, diretamente ou através de uma interação entre o tempo e o manejo. Frugívoros também não apresentaram efeitos significativos relacionados ao manejo florestal. Nectarívoros aumentaram tanto na floresta explorada como na floresta controle. Efeitos temporais de aumento ou declínio observados em guildas e em 12 espécies ocorreram tanto na floresta controle como na floresta explorada. Este resultado sugere que mudanças temporais na área explorada podem estar relacionadas à sucessão enquanto que mudanças temporais na floresta controle podem estar relacionados à exploração com intensidade de 40m³/ha de parcelas adjacentes.

This study compares the avian response to low impact selective logging by comparing bird species distribution in control and cut forest during five years, with before and post-harvest samples. Ordination analysis showed that the similarity of the bird community post-harvest was lesser than the similarity of samples before harvest. Moreover, the order of abundances of the 43 most common species changed between before and 3 to 4 years post-harvest in the logged forest. Logging affected capture rates for 20 species, either directly or with an interaction with time. The terrestrial insectivorous and mixed-species flocks were the guilds most affected by logging. Both guilds showed decline, correlated with time, in abundances in cut forest. Obligate army ant followers and arboreal insectivorous did not show differences between cut and control forest, but some species in these guilds showed logging effects, either directly or with an interaction between time and logging. Frugivores also did not show logging effects. Nectarivores increased in both the cut forest and in the control forest. Temporal effects of increase or decline occurred in guilds and in 12 species occurring in the cut and control forest. This result suggests that temporal changes in the cut forest may have resulted from succession and temporal changes in the control forest may have resulted from nearby harvest with 40m³/ha intensity in adjacent forest blocks.

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The role of bats as potential sources of transmission to humans or as maintenance hosts of leptospires is poorly understood. We quantified the prevalence of leptospiral colonization in bats in the Peruvian Amazon in the vicinity of Iquitos, an area of high biologic diversity. Of 589 analyzed bats, culture (3 of 589) and molecular evidence (20 of 589) of leptospiral colonization was found in the kidneys, yielding an overall colonization rate of 3.4%. Infection rates differed with habitat and location, and among different bat species. Bayesian analysis was used to infer phylogenic relationships of leptospiral 16S ribosomal DNA sequences. Tree topologies were consistent with groupings based on DNA-DNA hybridization studies. A diverse group of leptospires was found in peri-Iquitos bat populations including Leptospira interrogans (5 clones), L. kirschneri (1), L. borgpetersenii (4), L. fainei (1), and two previously undescribed leptospiral species (8). Although L. kirschenri and L. interrogans have been previously isolated from bats, this report is the first to describe L. borgpetersenii and L. fainei infection of bats. A wild animal reservoir of L. fainei has not been previously described. The detection in bats of the L. interrogans serovar Icterohemorrhagiae, a leptospire typically maintained by peridomestic rats, suggests a rodent-bat infection cycle. Bats in Iquitos maintain a genetically diverse group of leptospires. These results provide a solid basis for pursuing molecular epidemiologic studies of bat-associated Leptospira, a potentially new epidemiologic reservoir of transmission of leptospirosis to humans.

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O estado toxionômico dos mamíferos da Caatinga, avaliado por Mares et al. (1981), é modificado aqui, e uma lista dos mamíferos sobrevivente é incluída. Uma revista breve das contribuiçöes recentes a literatura científica sobre os mamíferos da Caatinga é transmitida também

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