Survival at the edge? Spatially-explicit modelling of plant diversity in networks of linear landscape elements

Basic data for this project

Description

Intensively-used agricultural landscapes are important for sustaining biodiversity because they cover more than half of the land area of Germany and, hence, interfere with large-scale ecological processes, such as species survival and spread. Intensification of land use has triggered a decrease of biodiversity in agricultural landscapes, but semi-natural edges between fields, and along roads and rivers (linear landscape elements) may mitigate long-term biodiversity loss by offering refugia and dispersal corridors for non-agrotolerant species. The level of biodiversity in networks of linear landscape elements is hypothesized to depend on local habitat quality and spatial connectivity that facilitates dispersal of species, but evidence is scarce because few studies have used spatially-explicit models. We want to assess the potential of linear landscape elements (LLE) in very-intensively used landscapes to sustain plant species diversity. Specifically, we want to find out 1.) which types of plant species benefit from LLE, 2.) which local and landscape factors facilitate high diversity, and 3.) which levels of habitat quality and connectivity are needed to reach a certain amount of diversity at the landscape scale? In a random sample of 36 study areas (4 km² squares) in the Münsterland, North-Western Germany, we record plant diversity and habitat quality on 432 sample plots and conduct inventories of the total number of plant species in the landscape. We construct spatially-explicit models of the study areas based on remote sensing images and cadastral maps to measure the connectivity of LLE networks. We use regression models to predict the total plant diversity and the diversity of different functional groups that can be expected to survive in LLE networks depending on connectivity and habitat quality and to assess the conductivity of agricultural landscapes for spread of non-agrotolerant species.