DOI: 10.5061/dryad.j3tx95xkh
title: The data table of eleven invasive species in Hungary and Romania: Invasive species' cover, invasive species' traits, basic characteristics, trait composition, functional diversity indices and soil parameters of recipient plant communities

description: We studied 11 widespread herbaceous invasive alien species of East-Central
 Europe and their 16 impact metrics (resident plant communities’ ecological
 characteristics, trait composition, functional diversity, and soil
 parameters) by sampling invaded and similar, uninvaded sites
 (space-for-time substitution method). Our aim was to (1) investigate the
 detailed ecological impacts of invasive plants on native plant
 communities; (2) explore the type of cover-impact relationships across
 impact metrics and their consistency across species; (3) study whether the
 cover-impact relationship depends on functional traits of invasive
 species. We present the data table with the 11 invasive species: the
 status of the sites (invaded, uninvaded), the cover of invasive species at
 plot level, the invasive species traits (lifespan, height, SLA, seed mass,
 clonal spread, flowering duration), community characteristics (species
 richness and diversity, native vegetation cover and bare ground cover at
 plot level), trait composition of native plant communities (native
 vegetation height, CWM height, CWM SLA, CWM seed mass, CWM clonal spread),
 functional diversity (functional richness, functional evenness, functional
 divergence, functional distance, RaoQ) and soil properties (N, P, organic
 C, pH).
description: We surveyed various regions of Hungary and Romania, where one of
 the chosen invasive species achieved dominance in the recipient
 communities. The chosen invasive species were: <em>Ambrosia
 artemisiifolia</em> L., <em>Asclepias</em>
 <em>syriaca</em> L., <em>Erigeron</em>
 <em>annuus</em> L. (Desf.), <em>Erigeron</em>
 <em>canadensis</em> L., <em>Gaillardia</em>
 <em>aristata</em> Pursh, <em>Helianthus</em>
 <em>tuberosus</em> L., <em>Impatiens</em>
 <em>glandulifera</em> Royle, <em>Reynoutria</em>
 <em>japonica</em> Houtt., <em>Rudbeckia</em>
 <em>laciniata</em> L., <em>Solidago</em>
 <em>gigantea</em> Aiton, <em>Symphyotrichum</em>
 <em>lanceolatum</em> Nesom. agg. To infer the effects of an
 invasive species on native plant communities, we used the space-for-time
 substitution approach. We chose seven pairs of sites for each invasive
 species: ‘invaded sites’, where the invasive species had considerable
 cover, and ‘uninvaded sites’, where the invader had no significant cover
 (&lt; 5%) or was absent.  In all sites, we sampled
 the vegetation in three 3 m × 3 m plots per site. Fieldwork was carried
 out between 2017 and 2019. Percent cover of native vegetation, bare
 ground, and all vascular plant species was visually estimated. To
 characterize the effect of invasive species on the trait composition of
 the resident plant communities, we measured the height of native
 vegetation and the specific leaf area (SLA) of native species, while the
 seed mass and clonality of native plant species were extracted from trait
 databases. We collected soil samples from five randomly selected cores per
 site and were mixed and analysed for pH, organic carbon (C) in humus,
 phosphorus (P) and all nitrogen (N) content.