DOI: 10.5061/dryad.mkkwh70x8
title: Influence of climate, soil and land cover on plant species distribution in the European Alps

description: Although the importance of edaphic factors and habitat structure for plant
 growth and survival is known, both are often neglected in favor of
 climatic drivers when investigating the spatial patterns of plant species
 and diversity. Yet, especially in mountain ecosystems with complex
 topography, missing edaphic and habitat components may be detrimental for
 a sound understanding of biodiversity distribution. Here, we compare the
 relative importance of climate, soil and land cover variables when
 predicting the distributions of 2’616 vascular plant species in the
 European Alps, representing approximately two thirds of all European
 Flora. Using presence-only data, we built point-process models (PPMs) to
 relate species observations to different combinations of covariates. We
 evaluated the PPMs through block cross-validations, and assessed the
 independent contributions of climate, soil and land cover covariates to
 predict plant species distributions using an innovative predictive
 partitioning approach. We found climate to be the most influential driver
 of spatial patterns in plant species with a relative influence of ~58.5%
 across all species, with decreasing importance from low to high
 elevations. Soil (~20.1%) and land cover (~21.4%), overall, were less
 influential than climate, but increased in importance along the elevation
 gradient. Furthermore, land cover showed strong local effects in lowlands,
 while the contribution of soil stabilized at mid-elevations. The
 decreasing influence of climate with elevation is explained by increasing
 endemism, and the fact that climate becomes more homogeneous as habitat
 diversity declines at higher altitudes. In contrast, soil predictors were
 found to follow the opposite trend. Additionally, at low elevations,
 human-mediated land cover effects appear to reduce the importance of
 climate predictors. We conclude that soil and land cover are, like
 climate, principal drivers of plant species distribution in the European
 Alps. While disentangling their effects remains a challenge, future
 studies can benefit markedly by including soil and land cover effects when
 predicting species distributions.
description: - Compilation of plant species observations in the Europeans Alps
 from more than 200 contributors (shared
 upon reasonable request due to data policy)
 - Summary of ~90 environmental predictors (climate, soil, land
 cover) via PCA axes - Model fits/outputs/responses,
 predictors' evaluation/influence outputs -
 Vegetation, soil and elevation type of ~4'000 plant species generated
 from the Flora Alpina database - Each species'
 elevation values/ranges extracted with the observations and a Digital
 Elevation Model (DEM) - R scripts that allowed all
 analysis - Descriptive file providing links between
 species REF code and species name
description: - All the data and scripts necessary for analysis and plots are
 in the depository. - All model fits and spatial
 predictions are on demand due to storage limitation. -
 All species observations may be provided upon reasonable request due to data
 policy.