Provenance variation in functional traits of European forest trees: Meta-analysis reveals effects of taxa and age despite critical research gaps

Climate change is driving profound transformations in European forests. Understanding the adaptive potential of tree species is a key challenge for conservation and adaptation measures. A critical component of this adaptive potential lies in the intraspecific variation of functional traits. The long tradition in ecological genetics resulted in a plethora of studies across species, regions age classes and traits. Prior syntheses have rarely quantified trait-specific patterns and their variation across taxa and tree age. We conducted a systematic literature search to examine intraspecific variation in natural European tree populations. We identified four approaches to study intraspecific variation (i.e. provenance-effects, provenance environment interaction-effects, clinal-effects and transfer-effects). For each approach, we compared their prevalence to show an effect while also accounting for species, species group, and age. Our results found that intraspecific variation is common in Eur..., We conducted a systematic literature search of scientific articles on the 88 European tree species that are present in the European Forest Genetic Resource Program using the websites Web of Science and Scopus, We used the scientific and the botanical English names of European tree species in combination with the search terms: “local adaptation” OR “genetic heterogeneity” OR “intraspecific variation” OR “population genomics” OR “genecolog*” OR “(provenance AND clima* AND respon*))”. The query included searches in title, abstract, keywords (i.e., author keywords and keywords plus® in WOK). It was conducted on February 2nd, 2022, with no date range applied (Appendix 1).
Based on title and abstract, we selected 269 articles that were further examined for extraction by two reviewers (see Figure A1 for a flow diagram and Appendix 1 for a selection criteria list). If an article examined several species, we treated each species as a distinct case (see also Matensaz & Ramírez-Valiente (2019)..., , # Provenance variation in functional traits of European forest trees: meta-analysis reveals effects of taxa and age despite critical research gaps

[https://doi.org/10.5061/dryad.v15dv424v](https://doi.org/10.5061/dryad.v15dv424v)

Review of provenance trials and experiments in Europe. The focus lay in analyzing the prevalence of trait groups to show provenance effects, provenance environment interaction effects, clinal effects, and transfer effects. There are empty cells in some columns, and infilling these cells will interfere with the code.

## Description of the data and file structure

S1_Data_extractions.xlsx is a simple Excel sheet with single observations (i.e., tested trait-relationships) in rows. It consists of the following columns:

**Title:** Title of the article.
**Year:** Year of publication
**Paper.ID:** Identifier of research article
**Case.ID:** Identifier of case within the article. Observations within an article have been split for each species, analysis, a...,