Pollen-insect metanetworks in rural landscapes_data and code

Data and code supporting Hall et al., "Pollen-insect interaction meta-networks identify key relationships for conservation in mosaic agricultural landscapes"

Abstract

Flower-visitors use different parts of the landscape through the plants they visit, however these connections vary within and among land-uses. Identifying which flower-visiting insects are carrying pollen, and from where in the landscape, can elucidate key pollen-insect interactions and identify the most important sites for maintaining community-level interactions across land-uses. We developed a bipartite meta-network, linking pollen-insect interactions with the sites they occur in, to identify which land-use types in the field where insects were collected and at the landscape-scale (within 500 m of a site), are most important for conserving pollen-insect interactions. We compared pollen-insect interactions across four different land-uses (remnant native forest, avocado orchard, dairy farm, rotational potato crop) within a mosaic agricultural landscape. We sampled insects using flight intercept traps, identified pollen carried on their bodies and quantified distinct pollen-insect interactions that were highly specialised to both natural and modified land-uses. We found that sites in crops and dairy farms had higher richness of pollen-insect interactions and higher interaction strength than small forest patches and orchards. Further, many interactions involved pollinator groups such as flies, wasps and beetles that are often under-represented in pollen-insect network studies, but were often connector species in our networks. These insect groups require greater attention to enable wholistic pollinator community conservation. Pollen samples were dominated by grass (Poaceae) pollen, indicating anemophilous plant species may provide important food resources for pollinators, particularly in modified land-uses. Field-scale land-use (within 100m of a site) better predicted pollen-insect interaction richness, uniqueness, and strength than landscape-scale. Thus, management focused at smaller scales may provide more tractable outcomes for conserving or restoring pollen-insect interactions in modified landscapes. For instance, actions aimed at linking high-richness sites with those containing unique (i.e. rare) interactions by enhancing floral corridors along field boundaries may best aid interaction diversity and connectance. The ability to map interactions across sites using a meta-network approach is practical and can inform land-use planning, whereby conservation efforts can be targeted toward areas that host key interactions between plant and pollinator species.