Relative importance of the land-use composition and intensity for the bird community composition in anthropogenic landscapes.

Vincent Pellissier,Anne Mimet,Denis Couvet,Colin Fontaine,Jens‐Christian Svenning

doi:10.1002/ece3.3534

Abstract

Humans are changing the biosphere by exerting pressure on land via different land uses with variable intensities. Quantifying the relative importance of the land‐use composition and intensity for communities may provide valuable insights for understanding community dynamics in human‐dominated landscapes. Here, we evaluate the relative importance of the land‐use composition versus land‐use intensity on the bird community structure in the highly human‐dominated region surrounding Paris, France. The land‐use composition was calculated from a land cover map, whereas the land‐use intensity (reverse intensity) was represented by the primary productivity remaining after human appropriation (NPP remaining), which was estimated using remote sensing imagery. We used variance partitioning to evaluate the relative importance of the land‐use composition versus intensity for explaining bird community species richness, total abundance, trophic levels, and habitat specialization in urban, farmland, and woodland habitats. The land‐use composition and intensity affected specialization and richness more than trophic levels and abundance. The importance of the land‐use intensity was slightly higher than that of the composition for richness, specialization, and trophic levels in farmland and urban areas, while the land‐use composition was a stronger predictor of abundance. The intensity contributed more to the community indices in anthropogenic habitats (farmland and urban areas) than to those in woodlands. Richness, trophic levels, and specialization in woodlands tended to increase with the NPP remaining value. The heterogeneity of land uses and intensity levels in the landscape consistently promoted species richness but reduced habitat specialization and trophic levels. This study demonstrates the complementarity of NPP remaining to the land‐use composition for understanding community structure in anthropogenic landscapes. Our results show, for the first time, that the productivity remaining after human appropriation is a determinant driver of animal community patterns, independent of the type of land use.

Highlights

Within the context of the current biodiversity crisis (Ceballos et al, 2015), it is of vital importance to understand and monitor the impact of human pressures on ecosystems
We showed for the first time that the remaining productivity available to animals in human-dominated ecosystems is an important driver of animal community patterns
Richness and habitat specialization appeared to be especially sensitive to the spatial variations of productivity

Summary

Introduction

Within the context of the current biodiversity crisis (Ceballos et al, 2015), it is of vital importance to understand and monitor the impact of human pressures on ecosystems. Land use refers to the human use of lands, such as for cropping or pastures, and is linked to practices such as tillage and fertilization. The initiation of more-intensive uses of land (such as agriculture and urbanization) is usually linked to changes in land cover (such as deforestation), which is defined as the physical coverage of the land, for example, by grass and built-up areas. Land uses and land covers are widely employed proxies for the mapping and quantification of species habitats and the identification of human pressures on biodiversity (Hudson et al, 2014). For common birds in France, the literature usually recognizes three widespread habitat types based on land use: farmland, forest, and urban habitats (Julliard, Clavel, Devictor, Jiguet, & Couvet, 2006). We refer to land use to describe these combinations of land use and land cover

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