DOI: 10.5061/dryad.mkkwh710j
title: Data from: The leaf economic and plant size spectra of European forest understory vegetation

description: Forest understories play a vital role in ecosystem functioning and the
 provision of ecosystem services. However, the extent to which
 environmental conditions drive dominant ecological strategies in forest
 understories at the continental scale remains understudied. Here, we used
 ~29,500 forest vegetation plots sampled across Europe and classified into
 25 forest types to explore the relative role of macroclimate, soil pH, and
 tree canopy cover in driving abundance-weighted patterns in the leaf
 economic spectrum (LES) and plant size spectrum (PSS) of forest
 understories (shrub and herb layers). We calculated LES using specific
 leaf area (SLA) and leaf dry matter content (LDMC), and PSS using plant
 height and seed mass of vascular plant species found in the understories.
 We found that forest understories had more conservative leaf economics in
 areas with more extreme mean annual temperatures (mainly Fennoscandia and
 the Mediterranean Basin), more extreme soil pH, and under more open
 canopies. Warm and summer-dry regions around the Mediterranean Basin and
 areas of Atlantic Europe also had taller understories with heavier seeds
 than continental temperate or boreal areas. Understories of broadleaved
 deciduous forests, such as Fagus forests on non-acid soils, or ravine
 forests, more commonly hosted species with acquisitive leaf economics. In
 contrast, some coniferous forests, such as Pinus, Larix, and Picea mire
 forests, or Pinus sylvestris light taiga, and sclerophyllous forests, more
 commonly hosted species with conservative leaf economics. Our findings
 highlight the importance of macroclimate and soil factors in driving trait
 variation of understory communities at the continental scale and the
 mediator effect of canopy cover on these relationships. We also provide
 the first maps and analyses of LES and PSS of forest understories across
 Europe and give evidence that the understories of European forest types
 are positioned along different major axes of trait variation.
description: All vegetation data used in this study were obtained from the
 European Vegetation Archive (EVA; http://euroveg.org; project number 82).
 Further details on data collection and associated databases can be found
 on the EVA website. Trait data used in the
 study were obtained from the TRY database
 (https://www.try-db.org/TryWeb/Home.php). See "Material and
 Methods" in the reference paper for details on the processing of
 these data.
description: This dataset contains the list of plant occurrences and
 geographical and environmental attributes of the vegetation plots analyzed
 in the paper titled “The leaf economic and plant size spectra of European
 forest understory vegetation” by Padullés Cubino et al. (2021; Ecography;
 DOI: 10.1111/ecog.05598).  The dataset contains 3
 tables: “Metadata.csv”: It includes a
 description of the fields found in the two following tables.
 “Table_sites.csv”: It includes data on the standardized effect
 size of the community weighted mean (CWM.ses) and variance (CWV.ses) of
 the leaf economic spectrum (LES) and the plant size spectrum (PSS) of
 European forest understories. It also includes the environmental variables
 associated with the plots, their classification into different forest
 types according to the EUNIS 2017 classification, their location in
 1<sup>o</sup> × 1<sup>o</sup> grid cells, and the
 reference to the original datasets archived in the European Vegetation
 Archive (EVA;
 http://euroveg.org/eva-database-participating-databases).
 “Table_taxa.csv”: It includes the list of angiosperm plant taxa
 in selected vegetation plots and their relative abundance
 cover.