Use of Poisson spatiotemporal regression models for the Brazilian Amazon Forest: malaria count data

INTRODUÇÃO: A malaria é uma doença endêmica na região da Amazônia Brasileira, e a detecção de possíveis fatores de risco pode ser de grande interesse às autoridades em saúde pública. O objetivo deste artigo é investigar a associação entre variáveis ambientais e os registros anuais de malária na região amazônica usando métodos bayesianos espaço-temporais. MÉTODOS: Utilizaram-se modelos de regressão espaço-temporais de Poisson para analisar os dados anuais de contagem de casos de malária entre os anos de 1999 a 2008, considerando a presença de alguns fatores como a taxa de desflorestamento. em uma abordagem bayesiana, as inferências foram obtidas por métodos Monte Carlo em cadeias de Markov (MCMC) que simularam amostras para a distribuição conjunta a posteriori de interesse. A discriminação de diferentes modelos também foi discutida. RESULTADOS: O modelo aqui proposto sugeriu que a taxa de desflorestamento, o número de habitants por km² e o índice de desenvolvimento humano (IDH) são importantes para a predição de casos de malária. CONCLUSÕES: É possível concluir que o desenvolvimento humano, o crescimento populacional, o desflorestamento e as alterações ecológicas associadas a estes fatores estão associados ao aumento do risco de malária. Pode-se ainda concluir que o uso de modelos de regressão de Poisson que capturam o efeito temporal e espacial em um enfoque bayesiano é uma boa estratégia para modelar dados de contagem de malária.

Forest natural regeneration and biomass production after slash and burn in a seasonally dry forest in the Southern Brazilian Amazon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mating system parameters at hierarchical levels of fruits, individuals and populations in the Brazilian insect-pollinated tropical tree, Tabebuia roseo-alba (Bignoniaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Low levels of realized seed and pollen gene flow and strong spatial genetic structure in a small, isolated and fragmented population of the tropical tree Copaifera langsdorffii Desf

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hunting spiders of woodland fragments and agricultural habitats in the Atlantic rain forest region of Brazil

The hunting spider communities of the Dionycha clade were studied 1986 through 1988 in fragmented woodlands and secondary agricultural habitats of the Botucatu area in São Paulo state, Brazil. The original vegetation of mainly tropical Atlantic rain forest (Mata Atlantica) was cleared already 70 years ago. In a total sample of over 1000 adult spiders, 247 species belonging to 12 families Mere determined. A decreasing frequency and diversity of spiders rc as found if forest remnants were compared with sugar cane fields and cattle pasture. The specific composition of the spider fauna as surveyed in different habitats is discussed under ecological aspects and in relation to the history of land use.

Phytoplankton assemblages in a reservoir cascade of a large tropical - subtropical river (SE, Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Input of litter in deforested and forested areas of a tropical headstream

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Feeding selectivity of ichthyofauna in a tropical stream: space-time variations in trophic plasticity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Time-course of photosynthetic induction in four tropical woody species grown in contrasting irradiance habitats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vertebrate dispersal syndromes along the Atlantic forest: broad-scale patterns and macroecological correlates

Aim To assess the geographical variation in the relative importance of vertebrates, and more specifically of birds and mammals, as seed dispersal agents in forest communities, and to evaluate the influence of geographical and climatic factors on the observed trends.Location One hundred and thirty-five forest communities in the Brazilian Atlantic forest.Methods We collected data on dispersal modes for 2292 woody species. By combining species x site with species x trait matrices, we obtained the percentages of endozoochory, ornithochory, mastozoochory and the mean fruit diameter for the local forest communities. We used Spearman's correlation to assess bivariate relationships between variables. Subsequently, we performed paired t-tests to verify if variations in frequency of dispersal modes and mean fruit diameter were influenced by altitude or temperature. Then, we applied multiple linear regressions to evaluate the effect of geographical and climatic variables on variation in the relative frequency of dispersal modes and mean fruit diameter across communities.Results We found no consistent latitudinal or longitudinal trend in the percentage of vertebrate-dispersed species, neither bird- nor mammal-dispersed species along the Atlantic forest. Endozoochory was affected chiefly by annual mean rainfall, increasing towards moister sites. Forest communities located at higher altitudes had a higher percentage of bird-dispersed species. Even when sites with identical values of annual mean temperature were compared, altitude had a positive effect on ornithochory. Conversely, we found a higher percentage of mammal-dispersed species in warmer forests, even when locations at the same altitudinal belts were contrasted. Fruit diameter was clearly related to altitude, decreasing towards higher elevations.Main conclusions This is the first analysis of a large data set on dispersal syndromes in tropical forest communities. Our findings support the hypotheses that: (1) geographical variation in the relative number of fleshy fruit species is mainly driven by moisture conditions and is relatively independent of geographical location, and (2) broad-scale trends in fruit size correspond to geographical variation in the relative importance of mammals and birds as seed dispersal agents at the community level.

Candida flosculorum sp nov and Candida floris sp nov., two yeast species associated with tropical flowers

Two ascomycetous yeast species, Candida flosculorum sp. nov. and Candida floris sp. nov., were isolated from tropical flowers and their associated insects. C. flosculorum was isolated from flower bracts of Heliconia velloziana and Heliconia episcopalis (Heliconiaceae) collected from two Atlantic rain forest sites in Brazil. C. floris was isolated from flowers of lpomoea sp. (Convolvulaceae) growing on the banks of the river Paraguai in the pantanal ecosystem in Brazil and from an adult of the stingless bee Trigona sp. and a flower of Merremia quinquefolia (Convolvulaceae) in Costa Rica. C. flosculorum belongs to the Metschnikowiaceae clade and C. floris belongs to the Starmerella clade. The type strain of C. flosculorum is UFMG-JL13(T) (=CBS 10566(T) =NRRL Y-48258(T)) and the type strain of C. floris is UWO(PS) 00-226.2(T) (=CBS 10593(T) =NRRL Y-48255(T)).

Granivorous birds as potentially important post-dispersal seed predators in a Brazilian forest fragment

In tropical forests, rodents exert a prominent role as post-dispersal seed predators, while other vertebrates apparently have a minor effect on seed predation. In some forest fragments in southeast Brazil, however, the density of rodents is unusually low, whereas terrestrial granivorous birds are abundant. In this study, we used seeds of a second-growth tree (Croton priscus, Euphorbiaceae) to investigate experimentally the relative importance of rodents and birds as seed predators in a forest fragment. We also estimated the density of terrestrial granivorous birds and trapped small mammals. Results indicate that, as a consequence of decreased rodent population and increased bird abundance, the latter are at least as important as the former as the main post-dispersal seed predators of C priscus. We interpret such apparent imbalance in the interaction between C priscus and their seed predators as a possible consequence of forest fragmentation.

Nitrogen-tixing and vesicular-arbuscular mycorrhizal symbioses in some tropical legume trees of tribe Mimoseae

Response to mineral fertilization and inoculation with rhizobia and/or arbuscular mycorrhiza fungi (AMF) of the Anadenanthera colubrina, Mimosa bimucronata and Parapiptadenia rigida (Leguminosae-Mimosoideae) native trees from Brazilian riparian forests, were studied in nursery conditions. Each species was submitted to seven treatments, varying nitrogen and phosphorous fertilization and inoculation with rhizobia (r), mycorrhiza (m) or both (rm): NP, P, P + r, P + rm, N, N + m and N + rm. Results showed that AMF inoculations did not enhance the mycorrhizal colonization, and P uptake was not sufficient to sustain good growth of plants. The level of P mineral added affected negatively the AMF colonization in A. colubrina and M. bimucronata, but not in P. rigida. Native fungi infected the three legume hosts. The absence of mineral N limited growth of A. colubrina and P. rigida, but in M. bimucronata the lack of N was corrected by biological nitrogen fixation. N mineral added inhibited the nodulation, although spontaneous nodulation had occurred in A. colubrina and M. bimucronata. Rhizobia inoculation enhanced the number of nodules, nitrogenase activity and leghemoglobin content of these two species. Thus, the extent of rhizobial and mycorrhizal symbiosis in these species under nursery conditions can affect growth and consequently the post-planting success. (C) 2004 Elsevier B.V. All rights reserved.

Horizontal and vertical tree community structure in a lowland atlantic rain forest, southeastern Brazil

A estrutura horizontal e vertical do componente arbóreo foi investigada em um trecho de Floresta Atlântica baixo-montana através de um levantamento fitossociológico em dois blocos amostrais de 0,99 ha cada no Parque Estadual Intervales. Todos os indivíduos com DAP > 5 cm foram registrados. Foram amostrados 3.078 indivíduos distribuídos em 172 espécies. O índice de diversidade de Shannon foi de H' = 3,85 nat.ind.-1. A família Myrtaceae se destacou tanto em número de espécies (38) quanto em número de indivíduos (745) no levantamento. Euterpe edulis Mart. teve o maior valor de importância (33,98%), abrangendo 21,8% do total de indivíduos registrados. O índice de similaridade quantitativo foi maior do que o qualitativo, mostrando pouca variação estrutural entre os blocos amostrais, mas a grande quantidade de espécies pouco abundantes, resultou em pronunciadas diferenças florísticas entre eles. Uma análise de correspondência retificada (DCA) gerou três estratos verticais arbitrários. O estrato A (> 26 m) teve a menor densidade e foi bem representado pelas espécies Sloanea guianensis (Aubl.) Benth. e Virola bicuhyba (Schott. ex A.DC.) Warb. O estrato B (8 m < h < 26 m) mostrou a maior riqueza e diversidade florística, e o estrato C (< 8 m) a maior densidade. Euterpe edulis, Guapira opposita (Vell.) Reitz, Garcinia gardneriana (Planch. & Triana) Zappi e Eugenia mosenii (Kausel) Sobral foram bem representadas nos estratos B e C da floresta. A existência de estratos verticais em florestas tropicais é discutida, recomendando-se o uso da DCA para estudos da estratificação vertical em outras florestas tropicais.

Using network connectance and autonomy analyses to uncover patterns of photosynthetic responses in tropical woody species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)