DOI: 10.5061/dryad.2ngf1vhtz
title: Large-scale restoration of species-rich dry grasslands on arable land: Environmental filtering drives successful species establishment over a period of 10 years

description: Sowing of regionally specific seed mixtures on former arable land is
 increasingly used to restore species-rich grasslands, but it often faces
 important obstacles in environmental conditions and colonisation from
 preserved surrounding grasslands. Long-term landscape scale studies, which
 explore the processes governing plant establishment from seed mixtures and
 later colonisation from the surrounding landscape are scarce. We studied
 the species and functional trait composition of 32 grasslands restored
 1–11 years before the first sampling by sowing regional seed mixtures in
 the White Carpathian Mts (SE Czech Republic). We compared them with 23
 well-preserved permanent grasslands in their surroundings. In each
 grassland we estimated plant species cover in three plots of 25 m2, in
 restored grasslands in 2009, 2014 and 2019, in permanent grasslands in
 2009. The species composition of the restored grasslands converged towards
 the permanent grasslands due to expansion of dry grassland species and
 retreat of mesic grassland and weed species. The majority (60–71%) of the
 vegetation cover of restored grasslands was formed by sown species, while
 the species number was mainly determined by colonising unsown species
 (61–63%). The species number of restored grasslands remained lower than
 that in permanent grasslands. Functional trait composition (Community
 Weighted Mean) of the sown seed mixtures, permanent grasslands and
 restored grasslands overlapped in all three samplings. With increasing
 grassland age, species with resource-retaining traits of low specific leaf
 area and high leaf dry matter content, lower stature, higher seed mass,
 and lower capacity for clonal reproduction expanded. Functional trait
 diversity of the plots was mostly lower than expected by null model
 randomisations of community, which indicates strong environmental
 filtering. Comparison of newly colonising species and extinct species
 indicated that mainly species with traits similar to the rest of the
 community are able to colonise the grasslands successfully. Synthesis and
 applications. Sowing of regionally specific seed mixtures was successful
 and demonstrated to be a fast way of grassland restoration, particularly
 in terms of functional trait composition. The resulting species diversity
 depended on the colonisation processes, which are controlled by the
 functional composition of the local communities.
description: We repeatedly sampled (2009, 2014,
 and 2019) 32 grasslands restored on former arable land and compared them
 with 23 well preserved reference of permanent grasslands (sampled in
 2009). Grasslands (localities) were restored 1–11 years (age) before the
 first sampling by sowing regional seed mixtures in the White Carpathian
 Mts (SE Czech Republic). We analyzed species composition of grassland
 communities, and the sown seed mixture by ordinations and we classified
 them into following groups: Sown dry grassland species, Sown mesic
 grassland species, Unsown dry grassland species, Unsown mesic grassland
 species, Weedy species, Other species. We analyzed cover and number of species
 within those groups. We
 further analyzed functional trait composition by computing community
 weighted means of traits (CWM). The used traits were: Canopy height – height of the highest
 photosynthetic tissue in m. Seed mass – weight of one seed in
 mg. SLA – specific leaf
 area in m<sup>2</sup>/kg LDMC – leaf dry matter content in
 g/mg Connection persistence
 – persistence of connection between clonal ramets of plants in
 years Multiplication rate –
 number of offspring ramets produced by mother ramet per
 year      Lateral spread –
 distance to which plant can spread clonally in cm Terminal velocity – speed of the diaspore
 in the still air in m/s. Based on those traits and we further
 analyzed functional diversity of the communities, which was standardized
 by null model randomization of the communities (resulting in SES index).
 We used two types of null models. One restricted by species pool of each
 grassland (SES_local) and with unrestricted species pool allowing all
 species of the dataset appear in the community (SES_global).
 We also analyzed to which above
 described group newly colonizing and extinct species (species appearing or
 disappearing on individual grasslands in periods 2009-2014 and 2014-2019)
 belonged to and we analyzed the similarity of new colonizers and extinct
 species to the rest of the community in terms of their functional traits
 (MPD_CE).  We further related the traits of colonizing and extinct species
 to the rest of the community and compared the differences between them in
 the index Standardized mean difference (CWM_CE).
description: First cell of each sheet contains brief data description as
 comment. Variable names are kept as described in the manuscript (Mudrák et
 al., DOI: 10.1111/1365-2664.14456). Missing data are
 marked as "NA".