35Aim: We aimed to assess the contribution of marginal habitats to the tree species 36 richness of the Mata Atlântica (Atlantic Forest) biodiversity hotspot. In addition, we 37 aimed to determine which environmental factors drive the occurrence and 38 distribution of these marginal habitats. Brazil where it largely occurs, stretches for over 3,500km across equatorial, tropical 73 and subtropical latitudes, and is renowned worldwide for being one of the 35 74 biodiversity hotspots for conservation prioritisation (Myers et al., 2000). Its 75 importance is also demonstrated by its designation as one of the five primary 76 vegetation 'Domains' of Brazil (IBGE, 1993; Ab'Sáber, 2003), the others being the The prevailing land cover of these bordering Domains are semi-arid thorn woodlands distribution of rain forest species in the Atlantic Domain, which at its harshest 88 extremes give rise to distinct habitats (one for each factor), referred to as marginal 89 habitats. Therefore, the rain forest is placed by Scarano (2009) (Galindo-Leal et al., 2003; Tabarelli et al., 2004; 2005; Joly et al., 2014 203The data were originally compiled from an extensive survey of published and 217It also excludes checklists with low species richness (< 20 species), because this is 218 often due to low sampling/collecting efforts, which results in poor descriptive power. 219This study used a subset of tree inventories from the NTT database, The distribution of the sites in the ordination space yielded by NMDS (Fig. 3a waterlogged soils at positive scores (tropical riverine forests). 377The floristic composition of marginal habitats is not simply a nested subset of 378 the more species rich rain forest. The turnover component accounts for most of the 379 floristic dissimilarity of each marginal habitat in relation to rain forests (Fig. 4). 380Nestedness is higher than the turnover component in very few cases (i.e., few The forward selection procedure retained 13 environmental variables in the 390 model to explain the variation in tree species composition (Table 1). In partitioning 391 the variation explained by the retained environmental and spatial predictors, we 392 found that the environmental fraction explained 27% of the variation, 5% of which 393 was independent of spatial autocorrelation (P < 0.01). The environmental predictors 394could not account for a spatially structured variation of 12% (P < 0.01), and 61% of 395 the variation remained unexplained (see discussion for more details). 396The harshest extremes of the retained environmental variables (Table 1) rock outcrops (including campos rupestres) from all others vegetation types (Fig. 3a). 404Within the rock outcrop habitat, the frequency of frost was associated with the forests and tropical riverine forests (Figs. 2b and 3b). At the harshest extreme of the 414 drought-stress gradient (Fig. 3b) Fig. S1). Because the overall floristic dissimilarity between cloud forests and rain 430forests was relatively low (Fig. 3), we assessed the rates of endemism con...
The use of well-sampled regions and insightful environmental gradients can provide important theoretical knowledge for understanding the drivers of tropical forest patterns and processes, which are necessary for biological conservation. We investigated the variation in tree species composition across a vegetation gradient in the Subtropical Atlantic Forest, as well as various predictors that could impact such patterns. The exploratory and confirmatory analyses included 178 sampling units distributed among 13 different forest types containing binary occurrence records for 935 species from 25,546 trees.Confirmatory analyses were conducted considering spatial autocorrelation, a well-known factor responsible for type I error inflations. The floristic heterogeneity of the study area was revealed by clear patterns of floristic differentiation between vegetation types, as well as by the significant improvements in local models (GWR-geographically weighted regressions) over global models (OLS-ordinary least squares). We found that the observed floristic variation has most likely been driven by humidity from the Atlantic Ocean, low temperature extremes and geographic distance. The latter was revealed by the high contribution of spatial components to the partial models. These results from a shrinking biological hotspot, particularly those concerning the importance of temperature extremes, represent crucial data for identifying conservation priorities, especially considering the seriousness of the temperature shifts predicted by global climate change scenarios.
A mineração em minas gerais: uma análise de sua expansão e os impactos ambientais e sociais causados por décadas de exploração RESuMO: O estado de Minas Gerais vem sofrendo com a exploração de minério desde o começo da colonização no Brasil. Apesar disso, ainda hoje é o estado que mais possui reservas minerais, o que gera um embate entre produção mineral e conservação ambiental, uma vez que a extração do minério gera desmatamento e outros impactos ambientais. O objetivo desse trabalho foi obter um panorama sobre a expansão da mineração e os impactos resultantes dessa atividade ao longo dos anos no estado. Os resultados mostraram que nas últimas décadas houve um grande aumento da expansão de minas no estado, bem como impactos ambientais e de saúde pública nas cidades que abrigam minerações mais antigas. Assim, conclui-se que por ser uma fonte de economia importante para o Brasil, é preciso rever a política ambiental das grandes minerações, bem como aumentar a fiscalização por parte dos órgãos públicos para que possamos assegurar as fontes de minério, bem como qualidade ambiental para as futuras gerações. Palavras-chaves: Desenvolvimento sustentável; Unidades de conservação; Extração mineral; Meio ambiente. ABSTRACT:The state of Minas Gerais has been suffering from the mineral exploration since inception of colonization in Brazil. Despite this, today is the state that has more mineral reserves, which creates an encounter between mineral production and environmental conservation, since the mineral extraction generates deforestation and other environmental impacts. The aim of this study was to obtain an overview of the expansion of mining and the resulting impacts of mining over the years in the state. The results showed that in recent decades there has been a large increase in the expansion of mines in the state, as well as environmental and public health impacts in cities that harbor the oldest mining. Thus, it was concluded that to be an important source of savings for Brazil, it becomes necessary to review the environmental policy of large mining and increase supervision by the public agency so that we can ensure the sources of mineral and quality environmental for future generations.
Aim To determine the principal drivers of variation in the evolutionary diversity of forest tree communities, with a focus on the temperate forests of South America.Location Forests across southern South America, extending from tropical forests in southern Brazil, to the temperate forests of southern Chile and Argentina. MethodsWe compiled a database of 742 forest tree community inventories spread over six countries and 12 biomes, or major vegetation types. In total, these inventories covered 3075 species of shrubs and trees. We combined this dataset with a temporally calibrated phylogeny that included all species. For each community, we evaluated multiple measures of evolutionary diversity, including phylogenetic diversity sensu stricto (PD), which is the sum of the branch lengths of a phylogeny that includes all species in a community, and its equivalent standardized for variation in species richness (ses.PD), which we refer to as lineage diversity. ResultsWe found that biome affiliation is the most important determinant of the evolutionary diversity of woody plant communities, with climate also showing a significant influence. Communities in wet evergreen tropical forest have the highest species richness and the highest PD, but the lowest lineage diversity, while temperate forests in southern South America show the lowest species richness and PD, but the highest lineage diversity.Main conclusions Our results contradict the idea that temperate floras represent recently derived, evolutionarily poor subsets of tropical floras. Rather, the high lineage diversity we find in the temperate forest communities supports the 'austral conservatism hypothesis', which states that the flora of southern South america has evolved independently from the Neotropical Domain over tens of millions of years. Our identification of the evolutionary distinctness and richness of this flora suggests that it deserves as much conservation attention as the more species-rich tropical forests of South America and that southern South American forests should not be lumped into the Neotropical Floristic Province.
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