Sporormiella as a tool for detecting the presence of large herbivores in the Neotropics

The reliability of using the abundance of Sporormiella spores as a proxy for the presence and abundance of megaherbivores was tested in southern Brazil. Mud-water interface samples from nine lakes, in which cattle-use was categorized as high, medium, or low, were assayed for Sporormiella representation. The sampling design allowed an analysis of both the influence of the number of animals using the shoreline and the distance of the sampling site from the nearest shoreline. Sporormiella was found to be a reliable proxy for the presence of large livestock. The concentration and abundance of spores declined from the edge of the lake toward the center, with the strongest response being in sites with high livestock use. Consistent with prior studies in temperate regions, we find that Sporormiella spores are a useful proxy to study the extinction of Pleistocene megafauna or the arrival of European livestock in Neotropical landscapes

Effects of environmental conditions associated to the cardinal orientation on the reproductive phenology of the cerrado savanna tree Xylopia aromatica (Annonaceae)

O cerrado brasileiro vem sofrendo um processo intenso de fragmentação, que levou ao aumento de remanescentes sujeitos aos efeitos de borda e a alterações nas condições ambientais que podem afetar a fenologia das plantas. O objetivo deste trabalho foi verificar se a fenologia reprodutiva de Xylopia aromatica (Lam.) Mart. (Annonaceae) difere sob diferentes condições de luz em um cerrado sensu stricto no sudeste do Brasil. Comparamos a fenologia reprodutiva de árvores de X. aromatica distribuídas nas faces leste e sul do cerrado, observadas mensalmente de janeiro de 2005 a dezembro de 2008. A face leste apresentou maior incidência de luz, temperaturas e aberturas do dossel em relação à face sul. X. aromatica apresentou reprodução sazonal em ambas as faces do cerrado, mas a porcentagem de indivíduos, sincronia e duração das fenofases foram maiores na face leste. O estudo demonstrou a influência das condições ambientais associadas à orientação cardeal das faces do cerrado no padrão fenológico de X. aromatica. Respostas similares poderão ser observadas em outras espécies de cerrado, afetando os padrões de visitação floral e produção de frutos, o que reforça a importância de considerarmos a orientação cardeal nos estudos de efeitos de borda e fragmentação.The Brazilian cerrado has undergone an intense process of fragmentation, which leads to an increase in the number of remnants exposed to edge effects and associated changes on environmental conditions that may affect the phenology of plants. This study aimed to verify whether the reproductive phenology of Xylopia aromatica (Lam.) Mart. (Annonaceae) differs under different light conditions in a cerrado sensu stricto (a woody savanna) of southeastern Brazil. We compared the reproductive phenology of X. aromatica trees distributed on east and south cardinal faces of the cerrado during monthly observations, from January 2005 to December 2008. The east face had a higher light incidence, higher temperatures and canopy openness in relation to south face. X. aromatica showed seasonal reproduction at both faces of the cerrado, but the percentage of individuals, the synchrony and duration of phenophases were higher at the east face. The study demonstrated the influence of the environmental conditions associated to the cardinal orientation of the cerrado faces on the phenological pattern of X. aromatica. Similar responses may be observed for other species, ultimately affecting patterns of floral visitation and fruit production, which reinforces the importance of considering the cardinal direction in studies of edge effects and fragmentation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Estadual Paulista Instituto de Biociências Departamento de BotânicaUniversidade Estadual Paulista Instituto de Biociências Departamento de BotânicaFAPESP: 05/57740-0FAPESP: 07/59779-

Ecological strategies of Al-accumulating and non-accumulating functional groups from the cerrado sensu stricto

The cerrado's flora comprises aluminum-(Al) accumulating and non-accumulating plants, which coexist on acidic and Al-rich soils with low fertility. Despite their existence, the ecological importance or biological strategies of these functional groups have been little explored. We evaluated the leaf flushing patterns of both groups throughout a year; leaf concentrations of N, P, K, Ca, Mg, S, Al, total flavonoids and polyphenols; as well as the specific leaf area (SLA) on young and mature leaves within and between the groups. In Al-accumulating plants, leaf flushed throughout the year, mainly in May and September; for non-accumulating plants, leaf flushing peaked at the dry-wet seasons transition. However, these behaviors could not be associated with strategies for building up concentrations of defense compounds in leaves of any functional groups. Al-accumulating plants showed low leaf nutrient concentrations, while non-accumulating plants accumulated more macronutrients and produced leaves with high SLA since the juvenile leaf phase. This demonstrates that the increase in SLA is slower in Al-accumulating plants that are likely to achieve SLA values comparable to the rest of the plant community only in the wet season, when sunlight capture is important for the growth of new branches.A flora do cerrado é composta por espécies acumuladoras e não acumuladoras de alumínio (Al), coexistentes em solos ácidos, ricos em Al e com baixa fertilidade. Apesar da coexistência desses grupos funcionais, sua importância ecológica e suas estratégias biológicas são pouco conhecidas. Nós estudamos os padrões fenológicos de brotação foliar de ambos os grupos ao longo do ano, as concentrações foliares de N, P, K, Ca, Mg, S, Al, flavonoides totais e polifenóis e a área foliar específica (AFE) em folhas jovens e maduras, dentro e entre os grupos. Para as espécies acumuladoras de Al as brotações foliares foram distribuídas ao longo do ano, com maior intensidade entre maio e setembro; para as espécies não acumuladoras de Al observamos um pico de brotação durante a transição das estações seca e chuvosa. No entanto, estes comportamentos não podem ser associados às estratégias ligadas ao acúmulo foliar de metabólitos secundários por estes grupos funcionais. As espécies acumuladoras de Al apresentaram menores concentrações de nutrientes foliares, enquanto que as não acumuladoras concentraram mais macronutrientes e produziram folhas com alta AFE desde a fase juvenil. Isso demonstra que o aumento de AFE é mais lento nas espécies acumuladoras de Al, que devem atingir valores de AFE comparáveis ao resto da comunidade apenas na estação úmida, quando a captação de luz é importante para o crescimento de novos ramos.Coordenação de Aperfei çoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Estadual Paulista Instituto de Biociências Departamento de BotânicaUniversidade de São Paulo Faculdade de Ciências Farmacêuticas de Ribeirão Preto Departamento de Ciências FarmacêuticasUniversidade Estadual Paulista Instituto de Química Departamento de Química OrgânicaUniversidade Estadual Paulista Instituto de Biociências Departamento de BotânicaUniversidade Estadual Paulista Instituto de Química Departamento de Química OrgânicaFAPESP: 2010/07809-1FAPESP: 2012/13762-3FAPESP: 2007/59779-6FAPESP-VALE: 2010/51307-

Spatio-Temporal Differentiation and Sociality in Spiders

Species that differ in their social system, and thus in traits such as group size and dispersal timing, may differ in their use of resources along spatial, temporal, or dietary dimensions. The role of sociality in creating differences in habitat use is best explored by studying closely related species or socially polymorphic species that differ in their social system, but share a common environment. Here we investigate whether five sympatric Anelosimus spider species that range from nearly solitary to highly social differ in their use of space and in their phenology as a function of their social system. By studying these species in Serra do Japi, Brazil, we find that the more social species, which form larger, longer–lived colonies, tend to live inside the forest, where sturdier, longer lasting vegetation is likely to offer better support for their nests. The less social species, which form single-family groups, in contrast, tend to occur on the forest edge where the vegetation is less robust. Within these two microhabitats, species with longer-lived colonies tend to occupy the potentially more stable positions closer to the core of the plants, while those with smaller and shorter-lived colonies build their nests towards the branch tips. The species further separate in their use of common habitat due to differences in the timing of their reproductive season. These patterns of habitat use suggest that the degree of sociality can enable otherwise similar species to differ from one another in ways that may facilitate their co-occurrence in a shared environment, a possibility that deserves further consideration