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.

Estudos sobre estoque de nutrientes na serapilheira são importantes para consolidar informações sobre a ciclagem de nutrientes e produtividade em ecossistemas florestais. O objetivo deste estudo foi caracterizar o estoque de nutrientes na serapilheira acumulada em quatro tipos de vegetação no Cerrado, no estado de Goiás. A coleta da serapilheira acumulada foi realizada de forma aleatória em quatro tipos de vegetação (Área de Preservação Permanente, Cerrado Sentido Restrito, povoamento com Eucalyptus e povoamento com Pinus), utilizando uma moldura com 25 cm x 25 cm (0,0625 m2) de dimensão. A serapilheira foi triada nas frações folhas/acículas, galhos, cascas, materiais reprodutivos e miscelânea, com posterior determinação de massa seca, teor e estoque de nutrientes. O maior estoque de nutrientes foi encontrado na serapilheira acumulada na Área de Preservação Permanente, onde o cálcio é o elemento acumulado em maior quantidade quando comparado aos demais macronutrientes. Na serapilheira acumulada nos demais tipos de vegetação, o nitrogênio esteve estocado em maior quantidade. O nitrogênio é um nutriente de suma importância no metabolismo da planta, sendo essencial à fotossíntese. Para os micronutrientes, o elemento mais acumulado foi o manganês, na serapilheira produzida em todos os tipos de vegetação. O manganês tem função importante para as plantas, pois atua no desenvolvimento das raízes e na síntese de clorofila. Os elementos estocados em menores quantidades são o fósforo e enxofre. O gradiente de magnitude de estoque dos nutrientes variou de acordo com a fração da serapilheira e com o tipo de vegetação, não apresentado um padrão.

the abundance of the five groups of tomato pollinators. Bees with a smaller body size, such as Exomalopsis spp., responded at smaller scales, while bees with a larger body size, such as the Centris and Bombus/Eulaema groups, responded at larger scales. The abundance of all pollinator groups increased with native vegetation cover. Most groups showed higher abundances in landscapes with similarsize fragments. The results reinforce the recommendation for maintaining natural habitats around crop areas, even if fragmented, for the conservation of the tomato pollinator assemblage. These findings are valuable for planning landscape management in the studied area to improve bee conservation, ecosystem services, and food production.

Resumo: Este estudo foi realizado em um sistema de produção integrado lavoura-pecuária-floresta no município de Cachoeira Dourada, Goiás, Brasil. A pesquisa colabora para um melhor entendimento da interação planta-ambiente, esta foi realizada com o objetivo de analisar a entrada de luz em dois períodos diferentes (estação seca e chuvosa). Para a coleta da Densidade de Fluxo de Fótons (DFF) (µmol.m-2 .s-1 ) foi utilizado dois sensores de quanta LI-250 A, Li-cor Inc., USA, na faixa fotossinteticamente ativa. A coleta foi realizada de hora em hora, com início às 9h45min e término às 17h45min. Coletou-se o DFF controle -a pleno sol, e as demais coletas foram realizadas em quatro pontos: (1-no centro do renque de árvores, 2 -a 5m do renque, 3 -a 10m do renque e 4 -a 15m do renque), sendo que em cada ponto se obteve mais 4 repetições. De acordo com os resultados obtidos se verificou que houve diferenças entre os pontos escolhidos, sendo o ponto 10 e 15 metros com maior recebimento de faixa de Radiação Fotossinteticamente Ativa (RFA). Portanto, o sistema Integrado Lavoura-Pecuária-Floresta (ILPF) não reduziu a Densidade de Fluxo de Fótons (DFF). A maior DFF foi verificada no período de seca, porém, a maior variação da DFF foi encontrada no período chuvoso. Quanto maior à distância em relação aos renques, com eucaliptos, maior à incidência de radiação solar. Palavras -chave:Luminosidade; Produtividade; Fotossíntese; Agrossilvipastoril. Photon flux density in a crop livestock forest systemAbstract: This study was conducted in a crop livestock forest system in Cachoeira Dourada, Goiás state, Brazil. Aiming to contribute to a better understanding about plant-environment interaction, this study had as objective to analyze light input in two different periods (dry and wet season). For photon flux density (PFD) measurement, two quanta sensors (LI-250 A, Licor Inc., USA) were used, in photosynthetically active band. Data collection was done in each hour, starting at 9:45 and ending at 17:45, and also collected the control to full sun, and other collections in: (1 in the center of the row of trees, 2 -at 5 m of hedgerow 3 -at 10m of hedgerow 4-at 15m of hedgerow), in each point 4 replications were obtained. According to the observed results, it was possible to verify that there were differences among the chosen points, being the points 10 and 15 meters the ones that receive the most range of PAR.most receiving range (PAR). Therefore, CLFS system did not reduce photons flux density. Highest PFD was verified during the dry season however the highest variation was verified in the wet period. The greater the distance from the rows with trees, the greater the incidence of solar radiation.