15 research outputs found
Taxonomic and functional divergence of tree assemblages in a fragmented tropical forest
<p>We provide the data we used for the main analyses and the R function to
calculate the β-diversity between pair of plots.
In species x plots.csv, C1-C20 are the Reference plots, whereas E1-E10 and
FR1-FR18 are Edge and Fragments plots, respectively. In species X traits.csv: Specific leaf area = cm²/g, Leaf
area = cm², Wood density = g/cm<sup>3</sup>, Seed size = cm, Maximum height =
m. beta2a2.R is a function to construct
a matrix containing β-diversity values of each pairwise comparison.</p
Deteniendo el tráfico: reorganización de senderos de hormigas cortadoras de hojas tras su obstrucción en dos ambientes de bosque tropical húmedo
Las actividades humanas alteran la distribución y disponibilidad de los recursos para las especies, afectando negativamente a la biodiversidad. Se sabe que las hormigas cortadoras de hojas incrementan su adecuación en ambientes antropizados, como son las zonas de borde, remanentes de bosque pequeños y acahuales (bosques secundarios). Estos cambios pueden modificar las distintas dinámicas de forrajeo que incluyen cambios en el arreglo espacial y mantenimiento de los senderos de forrajeo. En este contexto, nosotros evaluamos el tiempo de reorganización de los senderos (TRS) de hormigas cortadoras de hojas (Atta cephalotes) ante una interrupción física para dos tipos de ambientes: bosque y acahual en función del flujo de hormigas por unidad de área (caudal). Encontramos que las hormigas siempre restituyeron su trayectoria original, independientemente del tipo de ambiente analizado. Nuestros resultados sugieren que el uso óptimo de los senderos de forrajeo amortigua los cambios en el TRS, permitiendo un aprovechamiento similar de las fuentes de recursos disponibles en ambientes diferentes. Por lo tanto, concluimos que la capacidad de reorganizar senderos de A. cephalotes no es dependiente del grado de perturbación al que se exponen las hormigas en ambientes tropicales antropizados
Data from 30 plant communities sampled in distinct ontogenetic stages at Brazilian Caatinga
Tables with species abundance data of 30 plant communities surveyed in distinct ontogenetic stages (seedling, sapling and adult) and the chronic disturbance predictors measured in each plot. We also measured the soil type of each plot to control its effect
What Shapes the Phylogenetic Structure of Anuran Communities in a Seasonal Environment? The Influence of Determinism at Regional Scale to Stochasticity or Antagonistic Forces at Local Scale
<div><p>Ecological communities are structured by both deterministic and stochastic processes. We investigated phylogenetic patterns at regional and local scales to understand the influences of seasonal processes in shaping the structure of anuran communities in the southern Pantanal wetland, Brazil. We assessed the phylogenetic structure at different scales, using the Net Relatedness Index (NRI), the Nearest Taxon Index (NTI), and phylobetadiversity indexes, as well as a permutation test, to evaluate the effect of seasonality. The anuran community was represented by a non-random set of species with a high degree of phylogenetic relatedness at the regional scale. However, at the local scale the phylogenetic structure of the community was weakly related with the seasonality of the system, indicating that oriented stochastic processes (e.g. colonization, extinction and ecological drift) and/or antagonist forces drive the structure of such communities in the southern Pantanal.</p></div
Meteorological data from the Nhumirim Ranch.
<p>Precipitation (left axis) and maximum and minimum average temperatures between February 2005 and December 2012 (right axis). The arrows indicate the peak periods of drought and rain that we selected for the analysis.</p
NRI and NTI index values for the anuran communities in rainy and dry periods at Nhumirim Ranch, Pantanal wetland, Brazil, using presence/absence and abundance metrics.
<p>*Significant values.</p><p>NRI and NTI index values for the anuran communities in rainy and dry periods at Nhumirim Ranch, Pantanal wetland, Brazil, using presence/absence and abundance metrics.</p
NRI and NTI values between seasons.
<p>Permutation test using mean difference in indices of phylogenetic structure of anuran communities, NRI and NTI, in rainy and dry seasons in the Nhecolândia region, Pantanal wetland, Brazil. The dashed lines indicate the actual mean difference between the periods (nri p/a p = 0.102, nti p/a p = 0.384, nri abd p = 0.076, nti abd p = 0.006).</p
Location Nhumirim Ranch.
<p>Location in South America of the study area, Nhumirim Ranch (square), in Pantanal floodplain of Brazil.</p
Values of standardized phylobetadiversity (betaNRI and betaNTI) in Dry-Dry, Rainy-Rainy, and Dry-Rainy periods.
<p>Symbols indicate statistical significance of a t-test comparing observed values versus expected value of zero for random data (*p<0.05).</p><p>Values of standardized phylobetadiversity (betaNRI and betaNTI) in Dry-Dry, Rainy-Rainy, and Dry-Rainy periods.</p
Relative change in mean phylogenetic distance across 40 tree communities in a 1000-km<sup>2</sup> forest landscape of Central Amazonia, Brazil.
<p>Negative values indicate loss of phylogenetic diversity over time.</p