DOI: 10.5061/dryad.cb13r
title: Data from: Land use history and seed dispersal drive divergent plant community assembly patterns in urban vacant lots

description: 1. Despite high levels of disturbance and habitat modification, urban
 ecosystems still host substantial levels of biodiversity. The processes
 that maintain existing levels of diversity, however, remain understudied.
 Identifying the links between urban ecological processes and patterns has,
 therefore, become a fundamental research goal to support urban
 biodiversity and ecosystem functioning. 2. We conducted a study to
 determine how the diversity and composition of urban plant communities is
 affected by spatially and temporally variable land use legacies. We
 constructed a chronosequence of vacant lot properties covering a range of
 3-22 years since demolition, in an urban neighborhood in Baltimore,
 Maryland (USA). Surveys of herbaceous plant species abundance were
 conducted during the summers of 2012 and 2013 in sections of each vacant
 lot where the building previously stood (the ‘building footprint’) and
 sections of the lot that was previously a backyard or garden (the ‘remnant
 garden’). 3. We found divergent patterns in plant community composition
 between areas of vacant lots with varying land use histories. This
 includes significant shifts in the functional composition of
 biotically-vectored seed dispersal strategies, as well as an increase in
 seed mass and terminal velocity trait values of plant communities in
 building footprints over time. Additionally, we found that communities in
 different sections of the same vacant lot tended to become more
 functionally dissimilar in dispersal strategies over time. In contrast, we
 found no significant changes in taxonomic diversity over time for any of
 our measures. 4. Policy implications: Our study suggests that
 regional-scale patterns of seed dispersal interact with heterogeneous land
 use legacies to structure urban plant communities. Although it has been
 suggested that highly altered local environmental conditions and
 competition from introduced species limit native plant diversity in urban
 environments, we find dispersal to be a more significant driver of urban
 plant community assembly patterns. Implementing management strategies that
 focus on habitat connectivity and augmenting species pools via seeding may
 present an effective strategy for promoting more successful establishment
 of diverse flora in urban environments.08-May-2017
description: Plant species by site
 matrixThis file contains the
 matrix of species abundances across sites used to conduct all analyses.
 The column "LOT" refers to the individual vacant lot,
 "TYPE" refers to whether the surveyed area was present in the
 building footprint section (BF) or remnant garden section (RG), and the
 remaining columns all refer to observed species (or genera) observed at
 each site, with estimates of their percentage cover.Species_x_SiteMatrix.csvVacantLots_DemolitionDateThis file continues the estimated year of demolition for the vacant lots. Column "Code" refers to the id number which links the demolition date to the species x site matrix, "Address" is the street address in Baltimore, MD, USA where the vacant lot resides, "Source" refers to whether the date of demolition was estimated from demolition records from the Baltimore City Archives or from high resolution aerial photographs, "Demolition date" is the year in which the vacant lot was created, and "TimeSinceDemolition" are the number of years between demolition and when vegetation was surveyed (2012).VacantLot_DemolitionDate.csvSpecies_x_TraitsMatrixMatrix of functional traits collected for all the species surveyed within the vacant lots. Traits which are categorical (presence/absence) are indicated with 1/0 designations. For continuous traits, terminal velocity is measured in m/sec, specific leaf area (SLA) is in m, Height is in m and seed mass is in g/1000 seeds. Sources for each trait are described within the accompanying paper, in Table 1. Missing data is indicated with by "NA".Community weighted means of functional traitsA .csv file containing the community weighted trait means of each building footprint and remnant garden community surveyed. Continuous trait means represent the mean value of the species present in that community, weighted by abundance. Categorical trait means are all binary (presence/absence) and represent the proportional abundance of the species possessing each trait in the community.CommunityWeightedMeans.csvRawSoilDataA .csv file containing raw soil results for a subset of sites surveyed. Organic matter is reported as %, and all other soil nutrients' units are in mg/kg. For more detailed information on the methodology for collecting and analyzing soil samples, please see: Johnson, AL, Tauzer EC, and Swan, CM. (2015). Human legacies differentially organize functional and phylogenetic diversity of urban herbaceous plant communities at multiple spatial scales. Applied Vegetation Science http://dx.doi.org/10.1111/avsc.12155