Biodiversity and trophic interactions in agricultural mosaic landscapes, comparing bees, wasps and their natural enemies

全球生物多样性正在以惊人的速度下降，传统的保护区不再足以减缓这种下降，因此管理土地用于保护的潜在贡献日益得到承认。这包括将视角从田野和农场扩大到景观层面，考虑到人为镶嵌景观中经常被忽视的空间和时间周转。在这里，我们将使用高度重复的研究设计，通过对标准化筑巢资源的实验暴露，使用诱捕筑巢的蜜蜂、黄蜂及其天敌来检验栖息地类型对景观多样性的相对重要性。我们将分析划分的生物多样性的规模依赖关系，量化宿主-寄生蜂和猎物-捕食者的相互作用，并使用完全量化的相互作用网络进行食物网统计(跟随Tylianakis等人。2007，自然445：2002-5)。我们将展示马赛克景观(和不同年份)中的主要生境类型如何对总体物种丰富度做出贡献，比较小麦、油菜、草原、田野边缘地带、休闲地带和林缘，这些都代表了人为干扰的梯度。我们将研究景观组成如何影响六种生境类型对物种丰富度的相对贡献，重点放在简单到复杂结构景观的梯度上。此外，我们预计敌人的丰富性与宿主/猎物的死亡率有关，因此我们将为这一高度争论的话题做出贡献。农业景观的镶嵌结构允许研究景观配置鲜为人知的影响，包括跨生境的溢出效应、(通过敌对的谷地)抑制扩散和(通过长满草的走廊)促进扩散。用有标记的蜜蜂和黄蜂个体进行的实验允许描述不同栖息地的觅食行为和资源利用。

Global biodiversity is declining at an alarming rate and traditional conservation areas are no longer sufficient to slow this decline, so the potential contribution of managed land for conservation is increasingly acknowledged. This includes a broadening of the perspective from the field and farm to the landscape level, considering the often neglected spatial and temporal turnover in anthropogenic mosaic landscapes. Here we will use a highly replicated study design with the experimental exposure of standardized nesting resources to examine the relative importance of habitat type to landscape diversity using trap-nesting bees, wasps and their natural enemies. We will analyze the scale-dependence of partitioned biodiversity and quantify host-parasitoid and prey-predator interactions, as well as make food web statistics with a fully quantified interaction web (following Tylianakis et al. 2007, Nature 445: 2002-5). We will show how the major habitat types in our mosaic landscapes (and different years) contribute to overall species richness, comparing wheat, oilseed rape, grassland, field margin strips, fallows and forest margins, which represent a gradient of anthropogenic disturbance. We will examine how landscape composition influences the relative contribution of the six habitat types to species richness by focusing on a gradient of simple to complex structured landscapes. Further, we expect enemy richness to be related to host/prey mortality, so we will contribute to this highly debated topic. The mosaic structure of agricultural landscapes allow to study little known effects of landscape configuration, including spillover effects across habitats, inhibition of dispersal (by hostile cereal fields) and facilitation (by grassy corridors). Experiments with marked bee and wasp individuals allow to describe foraging behaviour and resource use across habitats.