DOI: 10.5061/dryad.z34tmpgfp
title: Selection on convergent functional traits drives compositional divergence in a tallgrass prairie restoration experiment

description: 1. Plant biodiversity is often partitioned into taxonomic diversity
 (species composition and abundance), phylogenetic diversity (breadth of
 evolutionary lineages) and functional diversity (resource‐use strategies
 or physical traits). Evaluating the effects and interplay of these
 dimensions can provide insights into how assembly processes drive
 compositional changes in plant communities. However, teasing apart the
 effects of different biodiversity dimensions is challenging in
 observational studies or retrospective analyses. 2. To evaluate how plant
 phylogenetic and trait history shape community establishment and turnover
 in restoration of a species‐rich North American tallgrass prairie, we
 conducted an experiment with 127 species planted in assemblages
 representing three levels of phylogenetic diversity (PD) and two of
 functional trait diversity (FD), holding starting species richness (SR)
 fixed. We tested whether PD and FD of planted assemblages predicted
 species diversity, compositional turnover and selection on functional
 traits. 3. Rank order of initial functional and phylogenetic diversity
 levels was maintained throughout the experiment, but neither diversity
 measure correlated positively with species richness by the end of the
 experiment. Phylogenetic and taxonomic beta diversity increased among all
 treatments. This increase in compositional beta diversity was associated
 with directional selection on phylogenetically dispersed functional
 traits. A set of functional traits associated with competitiveness in
 tallgrass prairies predicted species' cover for all survey years:
 stem dry matter content, leaf dry matter content, vegetative height and
 rhizomatous growth. Although all plots collectively converged on a similar
 suite of functional traits, functional beta diversity increased among
 high‐FD plots. 4. Synthesis. Neither higher functional nor
 phylogenetic diversity maintained higher species richness (SR) over time
 in our study. Although SR was not maintained, higher levels of PD and FD
 were. Both types of diversity shaped the rate at which plots changed in
 composition over time, with high diversity treatment plots increasing in
 beta diversity. Selection for traits convergent across the tree of life
 drove phylogenetic and compositional divergence among plots. While
 optimization of site‐specific functional traits may be most important for
 maintaining higher SR, our work implies that planting higher initial PD
 and FD may make grassland restorations more adaptable to site conditions
 that may be difficult to predict.
description: Data was collected from a mesic tallgrass prairie restoration experiment located at The Morton Arboretum in Lisle, Illinois, USA (41.821°N, 88.093°W). The experiment is a fully factorial phylogenetic diversity (PD) × functional diversity (FD) experiment with three PD levels (low, medium and high) and two FD levels (low and high) consisting of a total of 127 species characteristic of mesic eastern tallgrass prairies. Vegetative cover was collected twice annually. Plant functional traits were gathered for this experiment and from elsewhere (see manuscript).
description: R scripts are labeled for order of use. Not all coulmns of the
 spreadsheets provided are used in this study; please refer to the
 readme.txt, manuscript for details and R code directly.