DOI: 10.5061/dryad.mw6m9063g
title: Data from: Spatial scale matters for predicting plant invasions along roads

description: Biological invasions threaten global biodiversity and can have severe
 economic and social impacts. The complexity of this problem challenges
 effective management of invasive alien species as the contribution of many
 factors involved in the invasion processes across different spatial scales
 is not well understood. Here, we identify the most important determinants
 associated with the occurrence of two invasive alien plants, the North
 American goldenrods (Solidago canadensis and S. gigantea), commonly found
 in agricultural landscapes of Europe. We used Google Street View images to
 perform a remote, large-scale inventory of goldenrods along 1,347 roadside
 transects across Poland. Using open access geospatial data and machine
 learning techniques, we investigated the relative role of nearly 50
 variables potentially affecting the distribution of studied species at
 five spatial scales (from within 0.25 km to 5 km of the studied
 locations). We found that the occurrence of goldenrods along roadsides was
 simultaneously associated with multiple drivers among which those related
 to human impacts, climate, soil properties and landscape structure were
 the most important, while local characteristics, such as road parameters
 or the presence of other alien plants were less influential. However, the
 relative contribution of different variables in predicting goldenrod
 distribution changed across spatial scales. Synthesis: Mechanisms
 underlying plant invasions are highly complex and a number of factors can
 jointly influence the outcomes of this process. However, since different
 invasion drivers operate at different spatial scales, some important
 associations may be overlooked when focusing on a single spatial context.
 Although associations were consistent in direction (positive or negative)
 across scales, their relative influence on goldenrod occurrence often
 changed. Socio-economic factors were largely important at local scales,
 while the effect of landscape factors broadly increased with increasing
 spatial scale. We highlight that using multi-scale approaches involving a
 wide range of variables may enable setting priorities for the management
 of invasive alien plants.
description: # Data from: Spatial scale matters for predicting plant invasions along
 roads The file contains data on the occurrence of invasive alien goldenrod
 species recorded along 1,347 roadside transects in Poland using Google
 Street View images. The dataset also includes the environmental and human
 activity related characteristics potentially affecting the distribution of
 the studied species (i.a. human impacts, climate, soil properties,
 landscape structure, road parameters, presence of other alien plants). ##
 Description of the data and file structure The detailed description of the
 variables included in the dataset and data sources are provided in the
 Materials and methods section and in the supplementary material to the
 article *Spatial scale matters for predicting plant invasions along
 roads*. Most of the characteristics included in the dataset were measured
 at five spatial scales, i.e. within buffer zones of 250, 500, 1000, 2000
 and 5000 m from the surveyed transects. The scale at which a particular
 variable was measured is indicated in the column heading next to the
 variable name. If no scale is given in the column heading, the variable
 describes the local scale, that is, a transect or its immediate vicinity.
 **Variables included in the dataset:** ID - specific ID of a transect, X -
 longitude of the central point of a transect line in PUWG1992 metric
 coordinate system, Y - latitude of the central point of a transect line in
 PUWG1992 metric coordinate system, Goldenrods - giant goldenrod and/or
 Canadian goldenrod occurrence along a transect (1 – presence, 0 –
 absence), TransSections - number of transect sections established along a
 transect, GSVYear - year in which a GSV picture was taken, GSVMonth -
 month in which a GSV picture was taken, RoadWidth - road width [m],
 RoadCurv - road curvature calculated as the ratio of the length of a
 transect and the straight-line distance between the end points of a
 transect, RoadDir - road direction determined as the absolute deviation
 from NS direction in degrees, RoadClass - road class: 1=primary,
 2=secondary, 3=tertiary, 4=unclassified, 5=track, MownVerge - proportion
 of roadside (i.e. area within 30 m a transect line) considered mown,
 RiverDist - distance to the nearest watercourse [km], RiverDens - density
 of watercourses within a buffer [km/km<sup>2</sup>], RoadDens
 - road density within a buffer [km/km<sup>2</sup>], UrbanDist
 - distance to the nearest built-up areas [km], Artificial - coverage of
 artificial surfaces [%], Arable - coverage of arable land and permanent
 crops [%], Pasture - coverage of pastures [%], HetAgri - coverage of
 heterogeneous agricultural areas [%], Forest - coverage of forests [%],
 SemiNat - coverage of  semi-natural habitats [%], Water - coverage of
 wetlands and water bodies [%], LandscConfig - landscape configuration;
 density of land parcel borders within a buffer
 [km/km<sup>2</sup>], AgriIntens - agricultural intensity
 index, BoxElder - proportion of transect sections occupied by box elder
 *Acer negundo,* BlackLocust - proportion of transect sections occupied by
 black locust *Robinia pseudacacia,* CanHorseweed - proportion of transect
 sections occupied by Canadian horseweed *Conyza canadensis,* AlienPlants -
 number of alien plant species (other than goldenrods) observed along a
 transect, LandscComp - landscape composition; modified Simpson’s diversity
 index of land cover types within a buffer, Income - commune income per
 capita [PLN‧10<sup>3</sup>], PopDens - population density in a
 commune [1000 people‧km<sup>-2</sup>], Citizens65 - share of
 citizens older than 65 years in the total population of a given commune
 [%], PropWomen - proportion of women; number of women per 100 men in a
 commune, Unemploym - share of registered unemployed in the total
 working-age population of a given commune [%], HigherEd - share of higher
 educated citizens in the total number of economically active population of
 a given commune [%], GrowingSeas - growing season length [days], MeanTemp
 - annual mean temperature [°C], Precipitation - annual precipitation [mm],
 SolarRad - average annual potential incoming solar radiation
 [MJ‧m<sup>-2</sup>‧day<sup>-1</sup>], HFI - Human
 Footpront Index, Grassland - coverage of grasslands [%], Wetness -
 coverage of water and wet surfaces [%], NDVI - Normalized Difference
 Vegetation Index, Urban - coverage of built-up areas [%], Wasteland -
 share of uncultivated land [%], SoilCaCO3 - topsoil calcium carbonates
 content [mg‧kg<sup>-1</sup>], SoilK - topsoil potassium
 content [mg‧kg<sup>-1</sup>], SoilN - topsoil nitrogen content
 [g‧kg<sup>-1</sup>], SoilP - topsoil phosphorus content
 [mg‧kg<sup>-1</sup>], SoilpH - topsoil pH measured in water,
 BasalResp - potential soil microbial basal respiration [(µL O2/(g soil dry
 weight ⋅hr)], MicBiomass - soil microbial biomass [µg Cmic/g soil dry
 weight]