24 research outputs found
Braconidae (Hymenoptera) fauna in native, degraded and restoration areas of the Vale do Paraíba, São Paulo state, Brazil
This study sampled the diversity of Braconidae (Hymenoptera) in three different ecosystems: a degraded pasture, a secondary forest and an area in recovery process using native tree seedlings. The objective was to verify the use of those insects as a tool to check the local conservation by examining Shannon's diversity index. Ten subfamilies were identified, and Microgastrinae was predominant in a number of individuals. The diversity index calculated varies among the sampled areas, thus showing a correlation with vegetation cover with the number of individuals collected and number of subfamilies found. The results showed changes in the community of Braconidae, in the recovery area between the first and second year of study, thereby leading to the conclusion that they are indicators of environmental quality
Postharvest quality of strawberry fruits produced in organic and conventional systems Qualidade pós-colheita de frutos de morangueiro produzidos em sistemas orgânico e convencional
The aim of this study was to determine some physicochemical characteristics of fruits of eight strawberry cultivars (Aromas, Camino Real, Campinas, Dover, Oso Grande, Toyonoka, Tudla-Milsei and Ventana) cultivated in organic and conventional systems. The evaluated characteristics were soluble solids (SS), titratable acidity (TA), SS/AT ratio and anthocyanins. Evaluated sensory characteristics were flavor and appearance. The cultivars had a differential performance between themselves and among the systems for the evaluated characteristics. Generally, the conventional system produced fruit with higher levels of soluble solids and, organic system produced higher concentrations of anthocyanins. The fruits of the cultivar Toyonoka had the best soluble solids content in both systems and the anthocyanins content of 'Tudla-Milsei' and 'Camino Real' were proeminent in comparison to the other cultivars. The fruits from the organic system of production were preferred by judges on the sensorial attributes. The highest notes were given to the appearance of the cultivar Ventana in the conventional system and 'Tudla-Milsei' in the organic system.<br>O presente trabalho teve como objetivo determinar as características químicas e sensoriais de frutos de oito cultivares de morangueiro (Aromas, Camino Real, Campinas, Dover, Oso Grande, Toyonoka, Tudla-Milsei e Ventana) provenientes de sistemas orgânico e convencional de cultivo. As características químicas avaliadas foram sólidos solúveis (SS), acidez titulável (AT), relação SS/AT e teor de antocianinas. As características sensoriais avaliadas foram sabor e aparência. As cultivares apresentaram um comportamento diferenciado entre si e frente aos sistemas de produção para as características avaliadas. De modo geral, o sistema convencional produziu frutos com maiores teores de sólidos solúveis e o sistema orgânico, maiores valores de acidez titulável e maiores concentrações de antocianinas. Os frutos da cultivar Toyonoka apresentaram o maior teor de sólidos solúveis nos dois sistemas de cultivo avaliados. Destaque para o teor de antocianinas das cultivares Tudla-Milsei e Camino Real. Quanto às características sensoriais, os frutos provenientes do sistema orgânico de produção foram preferidos pelos julgadores para os atributos avaliados. As maiores notas foram atribuídas para a aparência dos frutos da cultivar Ventana no sistema convencional e de 'Tudla-Milsei' no orgânico
Macrophyte architecture affects the abundance and diversity of littoral microfauna
We tested the hypothesis that structural complexity is an important factor influencing the abundance and taxon richness of microfauna (e.g., rotifers, copepods, cladocerans) in littoral habitats. Research on littoral microfauna has to date focused mainly on field observations, which commonly show microfauna have preference for some macrophytes over others. However, while such studies commonly conclude that macrophyte architecture is a major determinant of these variations, independent factors may also be responsible (e.g., differences in macrophyte ages, differences in macrophyte bed densities and the depth of the respective macrophyte beds sampled). We used artificial macrophytes with three levels of complexity to keep the surface area and mass of the substrate sampled constant, and to control for confounding factors not related to the complexity of the plants. Our results support the hypothesis that structural complexity is an important factor influencing abundance and taxon richness, independent of other potential confounding factors. Microfaunal (mainly rotifer) abundance and richness were generally greater on more complex artificial macrophytes, likely a result of more complex substrates (1) providing a greater variety of habitat, (2) supporting a greater concentration or variety of food and/or (3) affording greater protection against predators. Less mobile surface-associated (i.e., benthic/periphytic) taxa were found to discriminate among substrates, whereas the abundance and richness of planktonic species were not affected by complexity level. Relatively low abundances and taxon richness of microfauna recorded in control samples, which did not contain artificial macrophytes, supports the contention that vegetated areas sustain a higher abundance and variety of species than non-vegetated areas