Diversity, floristic composition, and structure of the woody vegetation of the Cerrado in the Cerrado–Amazon transition zone in Mato Grosso, Brazil

The final publication is available at Springer via http://dx.doi.org/10.1007/s40415-015-0186-2We compared the diversity and species composition and the structure of the vegetation of three distinct Cerrado phytophysiognomies (Cerradão, Dense Cerrado, and Typical Cerrado) in the Cerrado–Amazon transition, Mato Grosso (Brazil). Species richness (observed and estimated) in the Cerradão and Dense Cerrado was higher than that recorded in the Typical Cerrado. Species diversity, based on a Rényi profile, was highest in the Dense Cerrado, in comparison with the other phytophysiognomies. We recorded a higher number of exclusive species in the Cerradão and a greater similarity (Morisita and Sørensen indices) between this vegetation type and the Dense Cerrado. While individuals were tallest in the Cerradão and Dense Cerrado and lowest in the Typical Cerrado, there was no difference among phytophysiognomies in mean diameter. A gradient in decreasing species richness and diversity (hypothesis 1) and vegetation vertical structure (hypothesis 3) was expected for the Cerradão–Dense Cerrado–Typical Cerrado; however, neither hypothesis was supported by the results. The Cerradão and Dense Cerrado were most similar in species composition not confirming hypothesis 2, which predicted that the two savanna vegetation types (Dense Cerrado and Typical Cerrado) were more similar to one another than either is to the woodland (Cerradão). Overall, the similarities among the three study communities depended on the type of parameter analyzed. While the species richness and the vertical and structure of the vegetation of the Cerradão and Dense Cerrado are closely similar, the Cerradão and Typical Cerrado are more similar in their species diversity. With regard to the floristic composition, Dense Cerrado occupies an intermediate position between Cerradão and Typical Cerrado.UNEMAT Graduate Program in Ecology and ConservationBrazilian Higher Education Training Program (CAPES)“Tropical Biomes in Transition – TROBIT”CAPES/Science without Borders ProgramPELD/CNPq (Long-Term Ecological Studies)PROCAD UnB/UNEMA

Climate change effects on the geographic distribution of specialist tree species of the Brazilian tropical dry forests

The aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenantheracolubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent). We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant’s adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly.Este estudo tem como objetivo avaliar a modelagem de nicho ecológico (ENMs) para três espécies especialistas (Anadenanthera colubrina, Aspidosperma pyrifolium e Myracrodruon urundeuva) de florestas tropicais secas (FTSs) no Brasil, considerando o cenário de mudanças climáticas: presente e futuro pessimistas (2080). Estas três espécies são decíduas e amplamente distribuídas pelas FTSs na América do Sul, sendo importante em estudos sobre os processos históricos e evolutivos experimentados por este ecossistema. A modelagem da distribuição geográfica potencial das espécies foi construída através do método de máxima entropia (Maxent). Foi observada uma expansão geral de áreas adequadas para a ocorrência das três espécies no futuro (cerca de 18%), embora tenha existido uma redução das áreas com alta adequabilidade ambiental na região da Caatinga. A precipitação do trimestre mais úmido e a sazonalidade da temperatura foram os fatores que mais contribuíram para os nossos modelos. As mudanças climáticas podem gerar períodos secos mais severos e longos, com aumento da temperatura e mortalidade de árvores em regiões tropicais. Neste cenário, as áreas atualmente ocupadas por florestas úmidas e savanas poderiam tornar-se mais adequadas para a ocorrência das árvores especialistas em FTSs, enquanto que as regiões ocupadas por Caatinga não poderiam suportar o nível futuro da não adequabilidade (por exemplo, aridez). Estudos multidisciplinares de longa duração são necessários para fazer previsões confiáveis de estratégias adaptativas das plantas e respostas às variações climáticas em FTS em nível de comunidade. Com base na elevada taxa de desmatamento, endemismo e ameaça, políticas públicas para minimizar os efeitos das mudanças climáticas sobre a biodiversidade encontradas dentro FTSs devem ser realizadas rapidamente

Climate change effects on the geographic distribution of specialist tree species of the Brazilian tropical dry forests

AbstractThe aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenantheracolubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent).We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant’s adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly

Climate change effects on the geographic distribution of specialist tree species of the Brazilian tropical dry forests

AbstractThe aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenantheracolubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent).We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant’s adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly

Xenon stability during load following operations in the PBMR core

Premise of research. This represents one of the first studies of the ecology, diversity, and structure of campos de murundus termite savannas in the vast seasonal wetlands of southern Amazonia. We aimed to improve understanding of this threatened system by assessing species richness, abundance, and co-occurrence among trees and herbs of murundus (earth mounds), investigating the environmental and biological mechanisms underlying these patterns, and discussing implications for biodiversity conservation. Methodology. We identified every tree, shrub, subshrub, and herb on 373 murundus across 11 ha at Araguaia State Park, southern Amazonia. We constructed species abundance distributions of trees and herbs, assessed best-fit models, and tested for nonrandom patterns of species co-occurrence using checkerboard scores. Using detrended correspondence analysis (DCA), we assessed the affinities among tree species and their positions in murundus. Pivotal results. A total of 166 species, 123 genera, and 49 families occupied the murundus. The species abundance distribution of trees followed a lognormal distribution, whereas that of herbs was best described by a Mandelbrot distribution. Observed C-score indices for trees and herbs were significantly larger than expected by chance, indicating nonrandom distributions and species segregation among murundus. DCA revealed a strong gradient in species occurrence within murundus, suggesting that internal structuring may be hydrologically based (e.g., variation in mound microrelief). Conclusions. Environmental (e.g., flooding) and biological (e.g., competition between plants) factors are important for controlling the occurrence of tree and herb species on the murundus. The murundus function as critical bases for the maintenance of species diversity in this extensive floodplain, thereby deserving recognition among ecosystems with high conservation priorities.Foundation for Research Support of Mato Grosso StateProgram of Academic Agreement/Coordination for the Improvement of Higher Level EducationBrazilian National Council for Scientific and Technological Development (CNPq)Foundation for Research Support of Federal District (FAPDF)Gordon and Betty Moore FoundationNERCERC Advanced GrantRoyal Society Wolfson Research Merit Awar

A. D. 1650-AN AGE FROM DARKNESS TO DAWN

Relation between human life and its natural environment is a very fascinating prob-lem and has attracted thinking minds from ancient times. In this lecture, taking as acase study the history and its natural background of China and India in the seventeenthcentury-an age from darkness to dawn-the age from medieval to contemporary worldan atempt is made to approach toward this problem and several important points of vieware suggested.Relation between human life and its natural environment is a very fascinating prob-lem and has attracted thinking minds from ancient times. In this lecture, taking as acase study the history and its natural background of China and India in the seventeenthcentury-an age from darkness to dawn-the age from medieval to contemporary worldan atempt is made to approach toward this problem and several important points of vieware suggested

Restinga and Lowland forests in coastal plain of southeastern Brazil: vegetation and environmental heterogeneity

It was evaluated the floristic similarity between two Atlantic Rainforest physiognomies in Brazilian coast area, herein called Restinga and Lowland forests. The hypothesis was that, due the differences in geomorphologic processes, these forests would differ on soil physical and chemical properties, floristic composition, live above-ground biomass. and litterfall production. It was sampled 1 ha (100 x 100 m) for each site located in Ubatuba, Sao Paulo state, SE Brazil. Within each hectare it was recorded trees with DBH >4.8 cm in all 10 x 10 m contiguous plots, and collected soil and litterfall samples. The cluster and ordination analyses indicated the two communities as distinct groups considering soil and floristic composition, agreeing with the initial hypothesis. Species diversity was higher (p 0.05) between the two forests. This apparent paradox could be explained assuming that, since different species establish themselves in the Restinga or Lowland forests and find a favorable spectrum of conditions and resources, they would tend to persist and to develop in that place; even so the edaphic conditions differ between the Restinga and Lowland forests, each species could respond in a particular way to these variations, and then both forests could reach similar values of biomass and litterfall production. It is probable that the environmental filter conditioned by soils has being important for the strong floristic segregation between these two forests.11210312