Abstract: P> Despite considerable interest in the application of plant functional traits to questions of community assembly and ecosystem structure and function, there is no consensus on the appropriateness of sampling designs to obtain plot-level estimates in diverse plant communities. We measured 10 plant functional traits describing leaf and stem morphology and ecophysiology for all trees in nine 1-ha plots in terra firme lowland tropical rain forests of French Guiana (N = 4709). We calculated, by simulation, the mean and variance in trait values for each plot and each trait expected under seven sampling methods and a range of sampling intensities. Simulated sampling methods included a variety of spatial designs, as well as the application of existing data base values to all individuals of a given species. For each trait in each plot, we defined a performance index for each sampling design as the proportion of resampling events that resulted in observed means within 5% of the true plot mean, and observed variance within 20% of the true plot variance. The relative performance of sampling designs was consistent for estimations of means and variances. Data base use had consistently poor performance for most traits across all plots, whereas sampling one individual per species per plot resulted in relatively high performance. We found few differences among different spatial sampling strategies; however, for a given strategy, increased intensity of sampling resulted in markedly improved accuracy in estimates of trait mean and variance. We also calculated the financial cost of each sampling design based on data from our 'every individual per plot' strategy and estimated the sampling and botanical effort required. The relative performance of designs was strongly positively correlated with relative financial cost, suggesting that sampling investment returns are relatively constant. Our results suggest that trait sampling for many objectives in species-rich plant communities may require the considerable effort of sampling at least one individual of each species in each plot, and that investment in complete sampling, though great, may be worthwhile for at least some traits.

Abstract: Growth defense tradeoff theory predicts that plants in low-resource habitats invest more energy in defense mechanisms against natural enemies than growth, whereas plants in high-resource habitats can afford higher leaf loss rates. A less-studied defense against herbivores involves the synchrony of leaf production, which can be an effective defense strategy if leaf biomass production exceeds the capacity of consumption by insects. The aim of this study was to determine whether leaf synchrony varied across habitats with different available resources and whether insects were able to track young leaf production among tree habitat specialists in a tropical forest of French Guiana. We predicted that high-resource habitats would exhibit more synchrony in leaf production due to the low cost and investment to replace leaf tissue. We also expected closer patterns of leaf synchrony and herbivory within related species, assuming that they shared herbivores. We simultaneously monitored leaf production and herbivory rates of five pairs of tree species, each composed of a specialist of terra firme or white-sand forests within the same lineage. Our prediction was not supported by the strong interaction of habitat and lineage for leaf synchrony within individuals of the same species; although habitat specialists differed in leaf synchrony within four of five lineages, the direction of the effect was variable. All species showed short time lags for the correlation between leaf production and herbivory, suggesting that insects are tightly tracking leaf production, especially for the most synchronous species. Leaf synchrony may provide an important escape defense against herbivores, and its expression appears to be constrained by both evolutionary history and environmental factors. © 2014 Springer Science+Business Media Dordrecht.

Abstract: In the dense tropical rainforest understorey, saplings exhibit different growth strategies aiming at reaching light levels better fitting their ecology. Investing mainly in height growth, at the expense of their width, a lot are close to mechanical instability. Tachigali melinonii, a long living heliophilic tree species, is frequently observed to be extremely slender and supported by neighbours. Such observations suggest an active growth control through the perception of mechanical environment. Mechanical environment or light availability, which one is the most influent on growth and slenderness (H/D)? To test this question, we recorded growth of control and staked saplings of two species with contrasting habits and ecology: T. melinonii, and Dicorynia guianensis, along a natural light gradient. Dicorynia, the more stable, responded more clearly to the staking treatment, showing slenderness increase when light is available, whereas for Tachigali, only light availability governed growth. For Tachigali, growth allocation is mainly governed by light availability and ontogeny, whereas Dicorynia is probably similar to the average tree strategy, using the thigmomorphogenetic physiological process to control its stability.

Abstract: Ethnopharmacological relevance Cutaneous and mucocutaneous leishmaniasis are neglected tropical diseases that occur in all intertropical regions of the world. Amazonian populations have developed an abundant knowledge of the disease and its remedies. Therefore, we undertook to review traditional antileishmanial plants in Amazonia and have developed new tools to analyze this somewhat dispersed information. Material and methods A literature review of traditional remedies for cutaneous/mucocutaneous leishmaniasis in the Amazon was conducted and the data obtained was used to calculate distribution indexes designed to highlight the most relevant uses in Amazonia. The cultural distribution index represents the distribution rate of a given taxon among different cultural groups and was calculated as the ratio of the number of groups using the taxon to the total number of groups cited. The geographical distribution index allowed us to quantify spatial distribution of a taxon's uses in Amazonia and was calculated geometrically by measuring the average distance between the points where uses have been reported and the barycenter of those points. The general distribution index was defined as an arithmetic combination of the previous two and provides information on both cultural and spatial criteria. Results 475 use reports, concerning 291 botanical species belonging to 83 families have been gathered depicted from 29 sources. Uses concern 34 cultural groups. While the use of some taxa appears to be Pan-Amazonian, some others are clearly restricted to small geographical regions. Particular attention has been paid to the recipes and beliefs surrounding treatments. Topical application of the remedies dominated the other means of administration and this deserves particular attention as the main treatments against Neotropical leishmaniasis are painful systemic injections. The data set was analyzed using the previously defined distribution indexes and the most relevant taxa were further discussed from a phytochemical and pharmacological point of view. Conclusions The Amazonian biodiversity and cultural heritage host a fantastic amount of data whose systematic investigation should allow a better large-scale understanding of the dynamics of traditional therapies and the consequent discovery of therapeutic solutions for neglected diseases. Distribution indices are indeed powerful tools for emphasizing the most relevant treatments against a given disease and should be very useful in the meta-analysis of other regional pharmacopeia. This focus on renowned remedies that have not yet benefitted from extended laboratory studies, could stimulate future research on new treatments of natural origin for leishmaniasis. © 2017 Elsevier Ireland Ltd

Abstract: Nineteen novel microsatellite loci were isolated from Adenomera andreae, a widespread Amazonian frog considered to be a species complex. Three multiplex kits were optimized. Genetic diversity was assessed in 66 individuals sampled in three populations along the West of the Approuague River catchment (French Guiana). We also tested the multiplex kits in four other Adenomera and nine Leptodactylus species with 43.4 and 17.5% success respectively.