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Our aims were to quantify and map the plant sub regions of the the Caatinga, that covers 844,453 km2 and is the largest block of seasonally dry forest in South America. We performed spatial analyses of the largest dataset of woody plant distributions in this region assembled to date (of 2,666 shrub and tree species; 260 localities), compared these distributions with the current phytogeographic regionalizations, and investigated the potential environmental drivers of the floristic patterns in these sub regions. Phytogeographical regions were identified using quantitative analyses of species turnover calculated as Simpson dissimilarity index. We applied an interpolation method to map NMDS axes of compositional variation over the entire extent of the Caatinga, and then classified the compositional dissimilarity according to the number of biogeographical sub regions identified a priori using k-means analysis. We used multinomial logistic regression models to investigate the influence of contemporary climatic productivity, topographic complexity, soil characteristics, climate stability since the last glacial maximum, and the human footprint in explaining the identified sub regions. We identified nine spatially cohesive biogeographical sub regions. Current productivity, as indicated by an aridity index, was the only explanatory variable retained in the best model, explaining nearly half of the floristic variability between sub regions. The highest rates of endemism within the Caatinga were in the Core and Periphery Chapada Diamantina sub regions. Our findings suggest that the topographic complexity, soil variation, and human footprint in the Caatinga act on woody plant distributions at local scales and not as determinants of broad floristic patterns. The lack of effect of climatic stability since the last glacial maximum probably results from the fact that a single measure of climatic stability does not adequately capture the highly dynamic climatic shifts the region suffered during the Pleistocene. There was limited overlap between our results and previous Caatinga classifications.

The responses of forest communities to interacting anthropogenic disturbances like climate change and logging are poorly known. Subtropical forests have been heavily modified by humans and their response to climate change is poorly understood. We investigated the 9‐year change observed in a mixed conifer‐hardwood Atlantic forest mosaic that included both mature and selectively logged forest patches in subtropical South America. We used demographic monitoring data within 10 1 ha plots that were subjected to distinct management histories (plots logged until 1955, until 1987, and unlogged) to test the hypothesis that climate change affected forest structure and dynamics differentially depending on past disturbances. We determined the functional group of all species based on life‐history affinities as well as many functional traits like leaf size, specific leaf area, wood density, total height, stem slenderness, and seed size data for the 66 most abundant species. Analysis of climate data revealed that minimum temperatures and rainfall have been increasing in the last few decades of the 20th century. Floristic composition differed mainly with logging history categories, with only minor change over the nine annual census intervals. Aboveground biomass increased in all plots, but increases were higher in mature unlogged forests, which showed signs of forest growth associated with increased CO2, temperature, and rainfall/treefall gap disturbance at the same time. Logged forests showed arrested succession as indicated by reduced abundances of Pioneers and biomass‐accumulators like Large Seeded Pioneers and Araucaria, as well as reduced functional diversity. Management actions aimed at creating regeneration opportunities for long‐lived pioneers are needed to restore community functional diversity, and ecosystem services such as increased aboveground biomass accumulation. We conclude that the effects of climate drivers on the dynamics of Brazilian mixed Atlantic forests vary with land‐use legacies, and can differ importantly from the ones prevalent in better known tropical forests. We investigated the 9‐year change observed in a mixed conifer‐hardwood Atlantic forest mosaic that included both mature and selectively logged forest patches in subtropical South America. Floristic composition differed between logging history categories, but did not change throughout the 9 studied years. Forest dynamics responded to local climate change differently depending on logging history.

Plant functional strategies are well-established for low- and high-stress environments, such as rainforests and deserts. However, in environments with low- and high-stress level fluctuation within years, the relationship between plant functional strategies and their spatial distribution is still poorly understood. We aimed to answer: what are the relationships between above- and below-ground traits in the largest seasonally dry tropical forest in the Americas? Do the studied species form detectable groups from the functional perspective? If detectable, do functional groups present distinct spatial distributions across the domain, mediated by spatial heterogeneity of aridity? We sampled a range of 16 above- and below-ground traits from the 20 most common native tree species. We performed a PCA to understand the species' main coordinated trade-offs, a k-mean analysis to test for functional groups, and a Ripley's-K analysis followed by a GLS model to test spatial functional groups distribution through the aridity gradient. We found five coordinated trade-offs representing different aspects of the conservative-acquisitive strategy continuum. Drought-tolerance and avoidance mechanisms seem linked to the conservative-acquisitive gradient, where water storage is positively correlated with acquisitive strategies. Different from other seasonally dry regions, acquisitive strategies are not limited by aridity. The presence of short-term water storage traits might buffer rainfall fluctuations, allowing acquisitive species to occupy more arid regions. This study sheds new light on the functional complexity of species from Americas seasonally dry tropical forests, for the first time including the relationship of its below- and above-ground traits.

The study of insects has historically been linked to the development of microscopy. As techniques have improved, research into insect morphology can increasingly contribute to a better understanding of the structures and functions of the morphological characters of insects' three tagmata. We propose the use of methodologies applied in microscopy as a way of improving and facilitating the study of the morphological characters of fly genitalia. In addition, flies preserved in 70% alcohol were used to verify the feasibility of distinguishing ultrastructural characters in the spermatozoa, when not previously fixed for the preservation of morphological structures. We have shown that it is viable to enhance preservation of specimens using a scanning electron microscopy technique. In addition, the observation of genitalia using this technique, together with confocal laser scanning microscopy, enables better visualization, description, and understanding of the morphological characteristics of fly genitalia. We also noted, in analysis using transmission electron microscopy, that it is possible to recover and describe some morphological features of the ultrastructure of Toxomerus politus (Say, 1823) sperm, obtained from flies stored in 70% alcohol for a long period of time. Comparison between the methods used to investigate the structures of T. politus, observed after preserving the specimen, already demonstrates the importance of using appropriate methodology as a starting point for reliable results. The methodologies and techniques adopted in this work have the potential to be extrapolated to research into other species of flies and other insects in a broad context. The use of microscopy as a morphological analysis tool in Toxomerus politus (Diptera, Syrphidae). A scientific‐artistic characterization of the male genitalia of Syrphidae.

A core question involving both plant physiology and community ecology is whether traits from different organs are coordinated across species, beyond pairwise trait correlations. The strength of within‐community trait coordination has been hypothesized to increase along gradients of environmental harshness, due to the cost of adopting ecological strategies out of the viable niche space supported by the abiotic conditions. We evaluated the strength of trait relationship and coordination in a stressful environment using 21 leaf and stem traits of 21 deciduous and evergreen woody species from a heath vegetation growing on coastal sandy plain in northeastern South America. The study region faces marked dry season, high soil salinity and acidity, and poor nutritional conditions. Results from multiple factor analyses supported two weak and independent axes of trait coordination, which accounted for 25%–29% of the trait variance using phylogenetically independent contrasts. Trait correlations on the multiple factor analyses main axis fit well with the global plant economic spectrum, with species investing in small leaves and dense stems as opposed to species with softer stems and large leaves. The species’ positions on the main functional axis corresponded to the competitor‐stress‐tolerant side of Grime's CSR triangle of plant strategies. The weak degree of trait coordination displayed by the heath vegetation species contradicted our expectation of high trait coordination in stressful environmental habitats. The distinct biogeographic origins of the species occurring in the study region and the prevalence of a regional environmental filter coupled with local homogeneous conditions could account for prevalence of trait independence we observed. We investigated leaf and stem traits of 33 species from a white sandy plain in northeastern South America to evaluate the strength of trait covariation in this stressful habitat.

Our aims were to quantify and map the plant ecoregions of the Atlantic Forest, a biodiversity hotspot that covers ca 150 million ha in eastern South America. We used a data set on the distribution of 4378 shrub and tree species across 711 localities. Plant ecoregions were identified using analyses of species turnover for both species occurrences and relative abundances. We interpolated NMDS axes of compositional variation over the entire the Atlantic Forest extent, and then classified the compositional dissimilarity according to the number of biogeographical ecoregions previously identified through K‐means analyses. We assessed the ability of environmental, historical vegetation stability and the current human footprint to explain the occurrence of the identified ecoregions through multinomial logistic regression models. We identified 21 spatially cohesive occurrence and 14 abundance ecoregions. Aridity, soil and historical biome stability were retained in the best model explaining both occurrence and abundance ecoregions. Broad compositional zones were identified through UPGMA cluster analysis of ecoregions, and formed north and south compositional blocks. Our work confirms the existence of a broad north–south divide within the Atlantic Forest, previously suggested based on climatic and amphibious data. Differences between the occurrence and abundance maps suggest the location of transition zones to neighbouring domains and endemism centres. Due to the aggregate nature of our analyses, site‐level disturbance degree was not considered, implying that human impacts could be broader then we could detect. There was limited overlap between our results and previous Atlantic Forest regionalization efforts, indicating that multi‐taxa, physiognomic and environmental regionalization schemes based on expert opinion or vegetation maps are poor proxies for compositional ecoregions.

Many biomes still lack an overall view of their macro-functional structure (i.e., natural biogeographical regions and zones), including the Atlantic Forest biodiversity hotspot. The effective design of protected areas depends on the spatial identification of units with ecologically distinct content, whether it be floristic, phylogenetic or functional. This study used a regionalization approach to identify the potential functional regions of the Atlantic Forest by interpolating functional data from forest remnants into the entire original occurrence area of the biome, including deforested lands. Conservation status was then estimated. Analysis of seven traits of leaf, wood, seed and plant size revealed that the biome is structured over 14 functional regions and three zones (clusters of regions). Functional regions represented specific combinations of traits rather than being characterized by extremely high or low values of a single trait. They retained an average of 29.5% of forest remnants (range: 7.63–54.66%) and 10.82% of protected areas (range: 0.35–35.78%). By analysing the functional space occupied by all regions, captured by two principal component analysis axes using the pixel-level information contained in interpolated trait maps, we showed that large parts of this space were not covered by forest remnants or protected areas and that the most represented regions had serious deficits in protected areas. Although the Serra do Mar mountain range in the south and south-east Atlantic Forest is relevant as a centre of species endemism and richness and has received considerable attention for carrying out ecological studies and creating protection areas, this range does not fully encompass the functional biodiversity of such a rich biome. Our results demonstrate the potential for combining regionalization and conservation approaches to unravel the macro-structures of biomes.

Environmental gradients are known to drive changes in mean trait values, but changes in the trait integration strength across local communities are less well understood, particularly with regard to possible links with species richness variation. Here, we tested if climate, soil, and topography gradients drive species richness indirectly via constraints on trait integration in the Atlantic Forest of South America. We evaluated seven traits (from leaf, wood, seed, and plant size) of 1456 species occurring across 84 local communities. Generalized least square models and a path model were applied to test direct and indirect relationships. Correlations were higher between leaf traits (average r = 0.28) and lower when other traits were included (average r = 0.16). In line with this result, species richness was related to a multivariate index of interspecific trait integration (ITI) computed for leaf traits, but not to the ITI for all the seven traits. Abiotic gradients influenced species richness both directly and indirectly through the leaf trait integration. A total of 33% and 26% of the variation in species richness and ITI, respectively, were explained by the models, with climatic conditions showing higher contribution than topographic and edaphic factors. These results support a significant but reduced environmental selection role behind the trait-based community assembly and may suggest that other processes are involved in the constrain of trait integration at larger spatial scales. In addition, different directional trends in trait–trait relationships across local communities suggest that global trait relationships may not necessarily hold at local contexts.

Plants adjust to abiotic conditions by changing their anatomical, morphological, and physiological traits. Traits can vary independently or in an integrated manner, known as trait variation and covariation respectively. It has been hypothesized that a trade-off would emerge along a gradient of abiotic constraints in which trait variation would be favored under resource-rich conditions while covariation under resource-limited ones. Although many studies have provided empirical support for this trade-off, a consensus has not yet emerged, due to a lack of support in some cases. This study investigated variation and covariation in three leaf and four wood traits of 74 woody species from a rainforest, a semideciduous forest, and a Restinga heath vegetation in the Atlantic Forest, which are subjected to different water-related constraints. We asked: Is there a variation-covariation trade-off within and across vegetation types? How does incorporating intraspecific variability change the magnitude and pattern of trait covariation? We found a variation-covariation trade-off and a positive relationship both within and across vegetation types. Wood variation was higher and covariation was lower in the rainforest, likely due to the greater water availability. Conversely, wood trait covariation was higher and variation was lower in the Restinga and seasonal semideciduous forest. Differences between vegetation types are likely related to the species’ strategies to prevent hydraulic failure, particularly for Restinga species that adjust their wood density and xylem vessel density in a coordinated manner. Accounting for intraspecific trait variability increased covariation across all vegetation types, particularly in the Restinga. This highlights the loss of functional information when analyses are based solely on species’ mean trait values. Our results also contribute to this discussion by providing evidence that the trade-off or a positive relationship between trait variation and covariation may be context-dependent.

Common species correspond to most of the structure and biomass of ecosystems, but the determinants of their distributions and the extent of their overlap are still a matter of debate. Here, we tested the hypotheses that (1) common herbaceous and woody species do not respond individualistically to environmental factors, but rather form groups of species with similar environmental affinities (archetypes), and (2) if local communities comprised cohesive systems, then archetypes of common species will occupy distinct portions of the coast with little or no overlap. We used a large set of climatic and soil variables in restinga heath vegetation along ~9000 km of eastern South American coastal plains. We used species archetype models, a new statistical approach that clusters species based on their environmental responses. We found five herbaceous species archetypes and 11 woody species archetypes, all responsive significantly although weakly to a mixture of climatic and soil variables. In most cases, there was considerable spatial overlap of different archetypes rather than separation along the coastline. Common species form groups with similar environmental affinities, but that did not respond strongly to environmental factors. This suggests an important role for dispersal in the explanation of heath vegetation floristic variation. Local community composition is influenced by groups of species that are not unique to any region and overlap extensively. Restinga heath vegetation communities seem to be considerably individualistic rather than cohesive systems.