A Ecofisiologia Vegetal é uma ferramenta usada para ajudar na compreensão e interpretação das respostas e aclimatação das pastagens às variantes ambientais. Nesse contexto, o presente trabalho teve como objetivo avaliar variáveis ecofisiológicas em Brachiaria decumbens, cultivadas em diferentes sistemas de manejo de pastagem em área de Cerrado do sul do Estado do Maranhão, Brasil. No experimento foi utilizado esquema fatorial 3x2x3, sendo constituído no primeiro fator: três sistemas de manejo de pastagem (sistema silvipastoril, rotacionado com regeneração nativa e extensivo), segundo fator: duas épocas do ano (seca e chuvosa) e terceiro fator (três horários do dia), em esquema de delineamento inteiramente casualizado, com nove repetições. Foram avaliadas: variáveis de eficiência fotoquímica, índice de performance e estimativa do teor de clorofila. Como resultado no estudo, observou-se que, o sistema extensivo, apresentou a maior quantidade das variáveis em estresse, apresentando assim comprometimento do aparato fotossintético, já o sistema silvipastoril, apresentou as melhores relações de eficiência fotoquímica e estimativa do teor de clorofila durante o dia e nas duas épocas do ano. A Brachiaria decumbens no sistema silvipastoril se mostrou com melhor eficiência ecofisiológica em todas as variáveis em relação aos outros sistemas, apresentando potencialidade nesse tipo de pastagem.

Plant Ecophysiology was used as a tool to interpret the responses and adaptation of pastures to environmental conditions. The objective of this study was to evaluate ecophysiological parameters in Brachiaria decumbens grown in different grazing systems in the Cerrado’s biome in the south state of Maranhão, Brazil. The experiment was conducted in a completely randomized design with nine replications, using a 3×2×3 factorial arrangement consisted of three grazing management systems (silvopastoral, a rotation system with regeneration of native vegetation, and extensive) two seasons (dry and rainy), and three evaluation times along the day. The photochemical efficiency, performance index, and estimation of chlorophyll content were evaluated. According to the results, most of the parameters of the variables evaluated for B. decumbens presented stress conditions, thus compromising their photosynthetic apparatus. B. decumbens presented the best photochemical efficiency and estimated chlorophyll content throughout the day in the silvopastoral system, in both evaluated seasons, therefore, it is a promising species of grass for this system.

The present work evaluated the influence of forest distance on predatory solitary wasps' abundance and richness and its relation to the natural biological control of the fall armyworm (Spodoptera frugiperda Smith - Lepidoptera: Noctuidae) in maize. The study consisted of two parallel lines of six experimental maize plots located at an increasing distance from a forest edge. Four trap-nests were placed in the vertices of each plot of the first line to evaluate the abundance and species richness of predatory solitary wasps. The larvae of the fall armyworm were sampled weekly by inspecting ten randomly chosen plants per plot. Predatory solitary wasp abundance (but not species richness) decreased whilst the fall armyworm abundance increased with the distance from the forest. Moreover, population densities of predatory solitary wasps and the fall armyworm were negatively correlated. Results suggested that the crop plantations located near forest fragments might benefit from the reduced pest problems as a result of increased natural biological control.