Navegando por Palavras-chave "Bees"

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    Áreas modificadas são acessíveis aos polinizadores: uma análise do forrageio de Melipona quadrifasciata como indicador de conectividade funcional
    (Universidade Federal de São Paulo, 2014-04-25) Souza, Tatiana Machado de [UNIFESP]; Boscolo, Danilo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Environmental changes can generate landscapes composed of a group of small, isolated patches of natural vegetation, interspersed with different types of land uses and occupation. This process interferes with plant reproduction through pollinators, what is directly linked to functional connectivity and accessibility of environments for these animals. The aim of this study was to estimate the accessibility of natural and cultivated environments of the study area for the species Melipona quadrifasciata by analysing their pollen foraging patterns in order to infer about the preferences of the species in different landscape contexts (more human modified ? over 55% of human modified spots, or less human modified ? under 55% of human modified spots), as well as inferring on the functional connectivity of these environments. For this, we allocated 15 artificial nests of M. quadrifasciata within those two different contexts. Three control colonies were allocated adjacent to the crops, while the others were placed in natural areas between 500m to 2000m away from the crops to assess in what situations the bees would forage mainly in the crops or stay in natural areas. We also made transects around the colonies to estimate available resources and acknowledge the surrounding flora, whith preparation of herbarium specimens with available pollen from natural and agricultural areas. We also collected pollen directly from the bee?s pollen basket, to know the foraging pattern of the species from the resources collected. The diversity of pollens collected by the bees was largely dependent on the distances between the crop and colonies. Collected diversity was further influenced by the association between distance and diversity of environments around each colony. Considering the data obtained and the foraging strategy of the M. quadrifasciata, it is possible to derive an indirect measure of the functional connectivity of the study area for these pollinators, what have direct influence on their movement and hence efficiency as a vector of pollen exchange in natural and farming environments. Maintaining healthy natural areas close to crop fields can be a way to keep the pollination system running in the long term, as this would ensure that natural areas around the colony are accessible enough to provide resources for nesting and food fairly constantly throughout the life of the colonies, ensuring their survival and associated environmental service.
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    Influência da distância da vegetação nativa sobre a diversidade de Himenópteros em olivais
    (Universidade Federal de São Paulo (UNIFESP), 2020-11-27) Oliveira, Christopher Henrique De [UNIFESP]; Puttker, Thomas [UNIFESP]; Universidade Federal de São Paulo
    Changes in land use caused by agropastoral activities have been the main cause of global biodiversity loss, mainly due to habitat loss of native species. With the increase in area and intensification of these activities expected for the coming years, actions that merge conservation of biodiversity with agricultural production systems become more urgent. Insects play important roles in maintaining essential ecosystem services for agriculture and Hymenoptera have a special role in providing endangered services, such as pollination and biological control. Here we investigate the effects of native vegetation on the diversity of hymenopterans around olive groves in the state of Minas Gerais, Brazil. We hypothesize that native vegetation act as a source of hymenopteran diversity for the olive groves. Therefore, we predict that the richness of families and abundance are negatively related to distance from native vegetation. In addition, we expect that the distance from native vegetation will influence the number of functional groups and the abundance per group, as well as community composition and functional group composition in olive groves. Hymenopterans were captured in 24 sampling stations during 7 capture sessions over ten months in pan-traps located at different distances from native vegetation in 3 different olive groves. The richness and abundance of families showed a negative relationship with the distance from native vegetation. The number of functional groups had no significant relationship with distance, but there was a disproportionate loss of parasitoids compared to other functional groups. The similarity of both community and functional groups between sampling stations decreased with increasing distance between stations, but only when abundance was included in the analysis. The results for richness and abundance corroborate the hypothesis that native vegetation represents a source of diversity for olive groves. The results for community composition based on abundance confirm the prediction that the distance from native vegetation has an influence on community composition, with less similarities between native vegetation and increasingly distant sampling stations. The results indicate that olive groves do not serve as habitat for many species of hymenopterans, which may have a consequence in the loss of pollination services and especially biological control, with the disproportionate loss of parasitoids. Conserve and include areas of native vegetation that allow habitat connectivity between these areas is essential for the existence of hymenopteran populations in the agricultural landscape.