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The selection of priority areas for nature conservation must balance the costs and benefits of conserving biodiversity, protecting ecosystem services, and permitting human activities or resource use. In this study, we selected priority areas for conservation in a seasonally dry tropical forest in Brazil and analyzed changes in the protection of ecosystem services and the conservation of plant biodiversity upon excluding areas with high opportunity costs (e.g., where income would be lost if natural areas were protected) and high population density. We identified two types of protected areas: sustainable use (SU) and strict protection (SP). Plant biodiversity (181 species) and supporting services (water balance, net primary productivity, and soil fertility) were used to determine the optimal locations of both types of protected areas. Provisioning services (water supply, fodder, and genetic resources) were used to determine SU priority areas, while regulating services (water purification, carbon storage, and erosion prevention) were used to determine SP areas. The selection of lowly populated or costly areas was associated with a small decrease in the representation of biodiversity (4% loss in SP and 6% loss in SU) and a large decrease in the representation of supporting (36% loss in SP and 31% loss in SU), regulating (41% loss in SP), and provisioning services (7% loss in SU). Our results reveal that selecting priority areas with low population density and low opportunity costs would decrease the overall representation of ecosystem services in protected areas but would still improve the cost efficiency of biodiversity conservation efforts.

Climate change impacts are important in shaping large ecotones, such as the transition zone between the Cerrado and Amazon rainforest (CAT) biogeographical domains. The accelerating rate of conversion of native vegetation, the most important factor for biodiversity loss in the Anthropocene, compounded by projected climate change impacts, requires a review of the effectiveness of existing designated protected areas (PA) and indigenous land (IL), where low-intensity and low-impact land use prevails. We identified priority tree species for conservation and quantified changes in their projected spatial distribution in future climate scenarios to estimate the conservation effectiveness of the current network of PA and IL in the CAT. Applying niche-based models to compare the geographical range of species in current and future climates, we estimated the displacement of species from their current distribution owing to projected climate change. We used four different IPCC emission scenarios for 2050 and quantified the losses or gains in species richness in PA and IL. All species were projected to suffer a reduction of climatically suitable area and a consequent range reduction. Inside both PA and IL there was a projected decrease in richness of the target species under climate change. The current PA network and designated IL in the CAT do not appear to safeguard future conservation of the species they currently contain. The future ‘climate refugia’ that our work identified could form the basis of plans to expand the protected area network in a region that remains under ever increasing pressure of deforestation in Brazil.

Phylogenies of legume taxa are ecologically structured along a tropical seasonality gradient, which suggests phylogenetic niche conservatism. This seasonality gradient spans Neotropical wet forests, savannas, and highly seasonal drought-prone woody vegetation known as the succulent biome. Ecological phylogenetic structure was investigated using a community phylogenetic approach. We further analyzed bioclimatic and other independent variables that potentially explained phylogenetic beta diversity among 466 floristic sites that spanned the savanna and succulent biomes in eastern South America. Explanatory variables were selected using variance inflation factors, information criteria, and the ability to explain both species and phylogenetic beta diversity. A model involving annual precipitation suggests that a threshold of

Variations of tree species composition and community structure and their relationship with environmental variables are described for five sites of the Atlantic rain forest in Picinguaba, southeastern Brazil, distributed along an elevation gradient sampled by plots located at the altitudes of 2, 100, 300, 600 and 1000 m a.s.l. Sampled trees with DBH ≥ 5 cm were identified to species level and their diameter and height were measured. Environmental variables obtained for each plot included 11 topsoil variables and altitude. The residuals of all linear models were tested for spatial structure and multivariate analyses were performed to seek for relationships between the overall species’ abundances and selected environmental variables. Although both forest physiognomy and species’ abundances did change with altitude, this was clearly sharp only from the coastal plain (2 m) to 100 m, and from 600 m to the summit (1000 m). The three mid-slope sites (100, 300 and 600 m) were rather undifferentiated, though they were richer in species and had taller canopy trees. The altitude and the edaphic variables silt, clay, pH and total exchangeable bases (TEB) presented significant correlations with the variations in species’ abundances, while only pH and TEB were significantly correlated with species richness. The present study demonstrates for the first time that the composition and structure of Atlantic Forest can change accompanying the soil and altitude variations over short distances.

Two 1 ha plots of a Southern Brazilian subtropical riverine forest, subject to different frequency and duration of floods, were compared to detect the differences in physiognomic structure, tree community composition, richness and diversity. Each plot was made up of 100 contiguous 10×10 m subplots, where 3451 trees with pbh ⩾15 cm were measured and identified. The survey observed 30 tree species, in the frequently flooded plot and 48 in the occasionally flooded plot. A detailed topographical and soil survey was carried out in both plots and indicated that the levels of organic matter and most mineral nutrients were higher in the frequently flooded stand. The forest understory was denser in the occasionally flooded stand which also showed taller emergent trees. Multivariate ordination and grouping techniques showed that the species’ abundance distribution was strongly related to the topographical variation. There was a clear pattern of species turnover according to topographic position, indicating that tree species developed different abilities to survive flooding events. As a result, the two plots also differed in their tree frequency per species regeneration, vertical distribution and dispersion groups. Both species richness and diversity decreased with increasing flood frequency, also showing a patchy distribution within both stands. At a local scale, flooding regime is regulating the spatial variation of α -diversity by forming different seral stages of predictable species composition. Compared to regularly flooded riverine and floodplain forests, riverine forests, with unpredictable flooding regimes, may show higher diversity at a local scale and more abundant opportunistic species of high environmental plasticity.

Summary The present contribution analyses the relationship between environmental variables and tree community spatial organisation within an area of tropical montane gallery forest in Itutinga, south-eastern Brazil (21°21’22”S and 44°36’50”W, 920 m of altitude). A main gradient was searched from the stream margins to the forest boundaries with the surrounding montane grasslands. To accomplish this, 28 10 × 30 m plots were laid out along this gradient. All trees with DBS (diameter at base of the stem) ⩾ 5 cm were identified and measured for their DBS and total height. Soil and topographic variables were obtained for all plots. Soil variables included pH, levels of mineral nutrients and organic matter, textural properties and soil moisture, this latter measured monthly during one year. The same variables were obtained for adjacent areas of montane grassland in order to investigate differences with the forest interior. The relationship between tree species distribution and environmental variables was assessed with traditional direct gradient analysis, along the SMB (Streamside-Middle-Border) gradient, and canonical correspondence analysis (CCA). The latter largely confirmed the former, since topographic variables related to the SMB gradient were the most strongly correlated to the species’ distribution. Although some soil chemical variables showed a significant variation along the SMB gradient, even extending to the grassland, this was considered an effect more than a cause of a main soil water and vegetational gradient. The spatial partitioning among tree species within the gallery forest as well as the definition of the sharp forest-grassland boundary may be seen as emergent properties of complex species-environment interactions triggered by differences in soil water regime. Even the establishment of a predominantly light-demanding tree community on the sunbathed forest border could possibly stem from soil water variations.

Summary The relationships between topography, soil taxonomic categories and tree species distribution were analysed in a riverside semideciduous forest on the margins of the Rio Grande, in Conquista, state of Minas Gerais, Southeastern Brazil. The forest was sampled by two transects made up of 50 contiguous 15 × 15 m2 quadrats (total 1.125 ha). Each transect started at the river margin and extended upslope so that they could include two soil catenas: the first with the sequence Ustifluvent, Haplustox and Ustorthent, and the second with Ustifluvent followed by Haplustult. A quick but more extensive survey was carried out in the whole forest fragment covering the same soil habitats in order to assess the extension of soil-species relationships found in the transects. A canonical correspondence analysis indicated that the species’ abundance distribution was significantly correlated with the soil habitats. Differences in soil drainage classes among the soils rather than their chemical properties appeared to be the leading factor: tree species distribution was strongly correlated with a wide hydrosequence ranging from poorly drained to strongly drained soils. The 55 most abundant species were classified according to their ecological group (regeneration guild) within the forest dynamics. A tentative ecological classification of those species combining their habitat preference in terms of soil drainage class and their growth strategy suggested that these factors play and important role in promoting the coexistence of tree species in that type of forest.

Summary The differences in plant community structure and soil properties between streamside and upland topographical sites were analysed in an area of montane semideciduous forest on the margins of the Camargos Reservoir, southeastern Brazil. The studied forest patch lies at the headwaters of two narrow streams and is surrounded by montane grasslands. The plant community was surveyed by one 30 × 150 m and one 30 × 165 m transects, both made up of 15 × 15 m contiguous quadrats. The first transect extended along one of the streams while the other linked the two streams by traversing the interfluve. Soil samples were collected from all quadrats and their texture and chemical properties were analysed in the laboratory. The streamside soils were tropical Podzolic Soils, characterised by clay depletion of the top layer with its accumulation in the deeper horizons. The upland soils were Cambisols, a 'maturing' soil type with no clear zonation. A canonical correspondence analysis indicated that the species' abundance distribution was significantly correlated with the two topographical sites as well as with some soil properties. The most abundant species appeared to vary from fairly exclusive streamside or upland preferentials to broadly indifferent for the two habitats. A tentative ecological classification of the 69 most abundant species according to their preference for streamside or upland habitat and to their growth strategy in the forest dynamics, is presented. An overall analysis of this classification along with the differences in soil properties between the two topographic sites gives evidence that the forest probably expanded from the two valley bottoms towards the upland sector occupying sites that were previously covered with montane grasslands.

Summary An intensive study was made of a gallery forest near Cuiaba, State of Mato Grosso. Analysis of the vegetation on 67 plots of 30 m 2 demonstrated a great deal of heterogeneity related principally to differences in topography and drainage. Four distinct communities were recognized: dry cerradao, wet cerradao, wet forest and swampy forest. Comparison of an informal site classification based on field observations, showed a very high degree of coincidence with ordination and a hierarchical classification based on analysis of floristic, topographic and soil data from plots. A total of 89 species with individuals ≥3 cm basal diameter were recorded. Soil data for the plots are also presented.