Navegando por Palavras-chave "Pollination"

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    Efeito da heterogeneidade da paisagem sobre redes de interações plantas-polinizadores
    (Universidade Federal de São Paulo, 2015-07-30) Tokumoto, Paola Mandetta [UNIFESP]; Boscolo, Danilo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Most studies about the effects of anthropogenic landscape changes on biodiversity have focused on parameters such as species richness and abundance. Few are those that aim to understand the effects of these disturbances on ecological processes such as pollination, which are important for the maintenance of natural and anthropic ecosystems. Pollinating insects are sensitive to changes in the landscape, what may be one of the leading forces for the global decline of these organisms. In this context, the analysis of plant-pollinators interaction networks allows us to better understand the resistance and resilience of pollination processes against landscape changes. Recent studies show that the abundance and richness of pollinators and agricultural productivity tend to be higher in landscapes that are more heterogeneous and with greater amount of forest. However, there is a necessity to better understand how different types of environments affect plant-pollinator interaction networks with a functional approach. This study evaluated the influence of functional heterogeneity of the landscape on plant-pollinator interaction networks, on the richness and abundance of insect flower visitors, and the richness of flowers available in Atlantic Forest fragments. Our main hypothesis was that in more diverse, forested, connected and with higher quality landscapes, we should find more resistant and resilient plant-pollinator interaction networks, as well as richer flower and pollinator communities. For this, we selected 12 landscapes, within a gradient of landscape diversity and forest proportion. In each central forest fragment, we actively collected floral visitors and flowering plants to build plant-pollinator networks for each landscape. We analyzed our data using a multiple competing hypotheses model selection approach based on the Akaike Information Criterion - AIC. Pollinator communities were richer and more abundant in landscapes with higher proportion of forest; more asymmetrical in landscapes with greater functional connectivity; more modular in better quality and more diverse landscapes; and with greater diversity of interactions in landscapes with higher quality and proportion of forest. In studies that aim to understand how landscape changes affect pollination in realistic scenarios, it is important to consider, in addition to the amount of forest, how the composition and configuration of different environments in landscape affect this ecological process.
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    Efeito da quantidade de floresta da paisagem sobre a estrutura de redes de interação planta-visitantes florais em áreas de restauração florestal
    (Universidade Federal de São Paulo, 2016-11-10) Martins, Mauricio Nogueira [UNIFESP]; Boscolo, Danilo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    With less than 16% of its original extent, the Atlantic Forest has been restored in order to rebuild the functional richness of biological communities. However, verification of the effectiveness of restoration actions consider only vegetation structure and species richness, while little is known about the functionality of these environments. Pollination is an ecological process and environmental service of great importance for plant reproduction and food production, and its agents are sensitive to environmental and landscape changes, so it should be considered in restoration actions. Through ecological network analysis, pollination networks between restoration areas and reference areas have been compared, focusing on the influence of local factors on restorations, neglecting the effect of the landscape structure in these areas. The objective of the present study was to evaluate the effect of the amount of forest surrounding forest restoration areas in the Atlantic Forest on the structure of the floral-plant interaction networks in these areas. Our hypothesis is that areas of forest restoration inserted in landscapes with high amount of forest have more complex and better structured networks than in areas with low amount of forest. The study was carried out in the municipalities of Antonina (Paraná) and Batatais (São Paulo), areas in different contexts of vegetation cover around forest restorations, where Antonina have greater vegetation cover than Batatais. We selected five landscapes in each region, high forest areas in Antonina, and low forest areas in Batatais, and sampled plants and their floral visitors for the construction of interaction networks, and then we analyzed the effects of the landscape on network metrics. The amount of forest in the landscape had little effect on the network metrics, which showed small and not very cohesive networks. However, in areas with high forest cover, the networks had a higher weighted connectance, indicating that the landscape factor may affect the pattern of interactions between plants and floral visitors that occur in areas of forest restoration in the early stages of succession. Our study suggests that the low effect of the amount of forest of the landscape on the structure of the studied nets can be due to other factors of the landscape and local factors of the restorations. It is also possible that restored forests in more advanced successional stages may are more attractive to floral visitors, and the amount of forest may be more relevant in this context. This project is linked to the Thematic Project approved by FAPESP Process no. 2013/50718-5, in its Module 5, related to the monitoring of fauna.
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    What do we know about the effects of landscape changes on plant-pollinator interaction networks?
    (Elsevier B.V., 2013-08-01) Ferreira, Patricia Alves; Boscolo, Danilo [UNIFESP]; Viana, Blandina Felipe; Universidade Federal da Bahia (UFBA); Universidade Federal de São Paulo (UNIFESP)
    Biotic interactions play an important role on the organization and persistence of biodiversity. Unnatural modifications of landscape structure such as habitat loss and fragmentation can isolate populations and disrupt biological communities, affecting species survival and altering the complex set of relationships between plants and pollinators. Plant-pollinator interaction networks have characteristics such asymmetry and nestedness that may influence the stability and robustness of networks to landscape changes. Species in mutualistic networks might respond to landscape modifications with a sudden collapse at critical habitat destruction thresholds. in this work we review general trends in the scientific literature related to the effects of landscape changes on plant-pollinator networks. for this, a survey in Scopus and Web of Knowledge databases was conducted in May 2011 using all seven possible combinations of the terms pollinat* with the terms landscape, habitat loss and network. We found 155 papers and 92% of those showed significant effects of landscape changes on pollinator diversity and plant reproductive success. Approximately 50% of all analyzed papers showed effects of agriculture intensification as a result of increases in the conversion of natural areas into agricultural crops on plant-pollinator interactions. Landscape modifications affected cross-pollination and the sexual reproduction of plants largely because of reduced diversity and availability of pollinators due to increased habitat isolation and reduction of floral resources and nesting areas in the remaining available habitat. An integrated approach concerning the effects of modified landscapes on natural ecosystems regarding how these variations can affect the stability and robustness of pollination networks can be extremely useful for conservation of plant-pollinators interactions, with positive overall consequences for conservation of plant, pollinators and pollination services in natural and agricultural ecosystems. (C) 2012 Elsevier B.V. All rights reserved.