Pollinators provide an essential service to natural ecosystems and agriculture. In tomatoes flowers, anthers are poricidal, pollen may drop from their pore when flowers are shaken by the wind. However, bees that vibrate these anthers increase pollen load on the stigma and in fruit production. The present study aimed to identify the pollinator richness of tomato flowers and investigate their morphological and functional traits related to the plant-pollinator interaction in plantations of Central Brazil. The time of anthesis, flower duration, and the number and viability of pollen grains and ovules were recorded. Floral visitors were observed and collected. Flower buds opened around 6h30 and closed around 18h00. They reopened on the following day at the same time in the morning, lasting on average 48 hours. The highest pollen availability occurred during the first hours of anthesis. Afterwards, the number of pollen grains declined, especially between 10h00 to 12h00, which is consistent with the pollinator visitation pattern. Forty bee species were found in the tomato fields, 30 of which were considered pollinators. We found that during the flowering period, plants offered an enormous amount of pollen to their visitors. These may explain the high richness and amount of bees that visit the tomato flowers in the study areas. The period of pollen availability and depletion throughout the day overlapped with the bees foraging period, suggesting that bees are highly effective in removing pollen grains from anthers. Many of these grains probably land on the stigma of the same flower, leading to self-pollination and subsequent fruit development. Native bees (Exomalopsis spp.) are effective pollinators of tomato flowers and are likely to contribute to increasing crop productivity. On the other hand, here tomato flowers offer large amounts of pollen resource to a high richness and amount of bees, showing a strong plant-pollinator interaction in the study agroecosystem.Keywords: agroecosystem, buzz pollination, Exomalopsis, poricidal anther, Solanum lycopersicum L. Alta riqueza de espécies de polinizadores nativos em plantações Brasileiras de tomateiro ResumoPolinizadores fornecer um serviço essencial para os ecossistemas naturais e para agricultura.

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The Cerrado biome has high species richness, endemism and spatial heterogeneity. Knowing the main characteristics and peculiarities of the flora is essential to adequately protect the species richness of the Cerrado. Therefore, the objective of this study was to analyze the species richness, alpha diversity and beta diversity of four vegetation types in the Paracatu River Basin (15°30'/19°30'S and 45°10'/47°30'W), Paracatu-MG. The four vegetation types cerrado (stricto sensu, "cerradão" or Savannah woodland, deciduous seasonal forest and riparian forest) were sampled following the Manual for Monitoring Permanent Plots of the Cerrado and Pantanal Biomes. Alpha diversity was assessed using the Simpson (Ds´) and Shannon & Wiener (H') indexes, and beta diversity using the Sørensen and Jaccard similarity indexes. The "cerradão" vegetation type had the highest number of species (106) and highest alpha diversity (3.83nats.ind -1 ). The cerrado stricto sensu had the lowest species richness (54 species) and alpha diversity value (2.65 nats. ind -1 ). Beta diversity was high (low Jaccard and Sørensen similarity) except between cerrado stricto sensu and "cerradão". The initial hypothesis of this study was rejected, because although the phytophysiognomies are located on the same land system, the beta diversity is high, except for the cerrado stricto sensu and "cerradão", which had similar diversity.

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Organic matter mineralization depends on how microbiota access nutrients, substrates and soil fertilization. This study shows influence of perennial (sugarcane) and annual (soybean and corn) crops on the activity of enzymes participating in the carbon, nitrogen and phosphorus cycles and proposes using hydrolases as bioindicators of soil quality. Samples were collected, during dry season and rainfall, in six different plots where sugarcane, soybean, corn and native Cerrado soils could be found at the same location. We evaluated chemical properties and activity of α-and β-glucosidase, acid phosphatase, protease and glycine aminopeptidase from 48 samples collected at 0-10 cm depth. Sample of monoculture soils showed low organic matter content, total organic carbon, total nitrogen and microbial biomass carbon. Native Cerrado soils had major activities of α-and β-glucosidase, acid phosphatase and glycine aminopeptidase while sugarcane areas showed minor values. Despite native vegetation replacement decreasing biodiversity and reducing soil biochemical activity, annual crops stimulate microbial activity in this environment and maintain nutrient cycling. Soil hydrolase activities can be used as bioindicators of these ecosystems.