DOI: 10.5061/dryad.cn921
title: Data from: Improving spatial predictions of taxonomic, functional and phylogenetic diversity

description: 1. In this study, we compare two community modelling approaches to
 determine their ability to predict the taxonomic, functional and
 phylogenetic properties of plant assemblages along a broad elevation
 gradient and at a fine resolution. The first method is the standard
 stacking individual species distribution modelling (SSDM) approach, which
 applies a simple environmental filter to predict species assemblages. The
 second method couples the SSDM and macroecological modelling (MEM -
 SSDM-MEM) approaches to impose a limit on the number of species
 co-occurring at each site. Because the detection of diversity patterns can
 be influenced by different levels of phylogenetic or functional trees, we
 also examine whether performing our analyses from broad to more exact
 structures in the trees influences the performance of the two modelling
 approaches when calculating diversity indices. 2. We found that coupling
 the SSDM with the MEM improves the predictions for the diversity facets
 compared with those of the SSDM alone. The accuracy of the SSDM
 predictions for the diversity indices varied greatly along the elevation
 gradient, and when considering broad to more exact structure in the
 functional and phylogenetic trees, the SSDM-MEM predictions were more
 stable. 3. SSDM-MEM moderately but significantly improved the prediction
 of taxonomic diversity, which was mainly driven by the corrected number of
 predicted species. The performance of both modelling frameworks increased
 when predicting the functional and phylogenetic diversity indices. In
 particular, fair predictions of the taxonomic composition by SSDM-MEM led
 to increasingly accurate predictions of the functional and phylogenetic
 indices, suggesting that the compositional errors were associated with
 species that were functionally or phylogenetically close to the correct
 ones; this did not always hold for the SSDM predictions. 4. Synthesis. In
 this study, we tested the use of a recently published approach that
 couples species distribution and macroecological models to provide the
 first predictions of the distribution of multiple facets of plant
 diversity: taxonomic, functional and phylogenetic. Moderate but
 significant improvements were obtained; thus, our results open promising
 avenues for improving the predictions of different facets of
 biodiversityacross broad environmental gradients when functional and
 phylogenetic information is available.
description: Plant traits: vegetative
 height and specific leaf areaThe table contains the
 average value for two functional traits measured in 175 grassland plant
 species. Data were field-sampled in a study area that covers approximately
 700 km2 of a mountain region located in the Western Swiss Alps. The traits
 are: vegetative height (VH in mm) and specific leaf area (SLA in mm2
 mg-1). Vegetative height is a stature trait associated with the plants’
 ability to compete for light, and specific leaf area is related to the
 plants’ ability to capture, use, and release resources to their
 environment, thereby providing a good estimate of the position of the
 species along the leaf economic spectrum. Each trait was log-transformed
 to conform to normality and scaled between 0 and 1. See Dubuis et al. 2013
 (DOI: 10.1111/j.1600-0587.2013.00237.x), for details on the measurements
 in the field.DubuisPottierGuisan_PlantTraits.txt