Effects of spatio-temporal resource availability on pollinators and pest-natural enemies in fragmented agricultural landscapes (FRAGMENT III)

我们的目的是阐明农业景观中特定花卉资源对红石匠蜂和欧洲果园蜂丰度和适合度的影响。这两种野生蜜蜂在洞巢独居蜜蜂群落中占主导地位，并为油菜、苹果和草莓等多种农作物授粉。我们的具体目标是：1)测试O. bicornis和O. cornuta的丰度和相对优势度如何受到首选花类型的数量和接近程度的影响。2)考察双角花和角花的幼虫食性和适合度受偏好花型数量和接近程度的影响。3)考察花资源可用性的时间是否决定了它们对双角花和角花的影响，早花植物的影响强于晚花植物。(4)考察木本生境的数量和邻近程度如何影响双角夜蛾和角夜蛾的寄生，从而改变目标(1)、(2)和(3)所研究的花卉资源有效性的积极效应。(5)根据巢内花粉和到景观中各自资源的最小距离估算双角夜蛾和角夜蛾的飞行距离。6)确定花资源可利用性对双角花和角花的影响最大的空间尺度。

We aim to disentangle the effects of specific floral resources in agricultural landscapes on the abundance and fitness of the red mason bees Osmia bicornis and the European orchard bee Osmia cornuta. These two species of wild bees dominate communities of cavity-nesting solitary bees and contribute to the pollination of a wide range of agricultural crops such as oilseed rape, apple and strawberry. Our specific objectives are:1) To test how the abundance and relative dominance of O. bicornis and O. cornuta is affected by the amount and proximity of preferred flower types.2) To test how the larval diet and fitness of O. bicornis and O. cornuta is affected by the amount and proximity of preferred flower types.3) To test if the timing of floral resource availability determines their effects on O. bicornis and O. cornuta, with early flowering plants having stronger effects than late flowering plants. 4) To test how amount and proximity of woody habitats affect parasitism of O. bicornis and O. cornuta, which may alter the positive effects of floral resource availability studied under objectives (1), (2) and (3).5) To estimate the flight distances of O. bicornis and O. cornuta according to the pollen found in the nests and the minimal distance to the respective resources in the landscape. 6) To determine the spatial scale at which floral resource availability effects on O. bicornis and O. cornuta are strongest.