Spatial mismatch analysis among hotspots of alien plant species, road and railway networks in Germany and Austria

<div><p>Road and railway networks are pervasive elements of all environments, which have expanded intensively over the last century in all European countries. These transportation infrastructures have major impacts on the surrounding landscape, representing a threat to biodiversity. Roadsides and railways may function as corridors for dispersal of alien species in fragmented landscapes. However, only few studies have explored the spread of invasive species in relationship to transport network at large spatial scales. We performed a spatial mismatch analysis, based on a spatially explicit correlation test, to investigate whether alien plant species hotspots in Germany and Austria correspond to areas of high density of roads and railways. We tested this independently of the effects of dominant environments in each spatial unit, in order to focus just on the correlation between occurrence of alien species and density of linear transportation infrastructures. We found a significant spatial association between alien plant species hotspots distribution and roads and railways density in both countries. As expected, anthropogenic landscapes, such as urban areas, harbored more alien plant species, followed by water bodies. However, our findings suggested that the distribution of neobiota is strongest correlated to road/railways density than to land use composition. This study provides new evidence, from a transnational scale, that alien plants can use roadsides and rail networks as colonization corridors. Furthermore, our approach contributes to the understanding on alien plant species distribution at large spatial scale by the combination with spatial modeling procedures.</p></div

Alien plant species hotspot distribution, road and railway networks and density distribution in Germany and Austria.

<p>All maps were generated with GIS soſtware (ArcGIS 10.1) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183691#pone.0183691.ref045" target="_blank">45</a>] with geographical background using data available under the Open Database Licence (“OpenStreetMap and contributors”; cartography licensed as CC BY-SA) <a href="http://www.openstreetmap.org/copyright" target="_blank">http://www.openstreetmap.org/copyright</a>, and the map of alien plant species hotspots was based on free available data from <a href="http://www.eea.europa.eu/data-and-maps/figures/actual-and-potential-future-alien" target="_blank">http://www.eea.europa.eu/data-and-maps/figures/actual-and-potential-future-alien</a>. All values were calculated by intersection in each spatial unit 5.5 km x 5.5 km.</p

Venn diagram showing the results of variation partitioning analysis on number of alien plant species in relation to road and railways density and the land use composition in each spatial unit.

<p>The diagrams represent the adjusted percentages of unique contribution of road and railways density, and dominant environment based on land use composition in Germany and Austria. The fraction between two overlapped circles represents the variation explained between the components while the residuals are the variation left unexplained by the canonical model. The fractions of variation displayed in the diagram are computed from adjusted r². Both unique contributions were statistically significant (*).</p

Results of GLMM for best model relating number of alien plant species to road density and railway density for each spatial unit in Germany and Austria.

<p>The interaction between country and dominant environment was added as random factor in the model (11 groups). The table shows estimates, 95% confidence intervals (CI), SE, Z and p values.</p

List of GLMs performed in this study, relating number of alien plant species separately to road density (model 2) and to dominant environment based on land use composition (model 3) for each spatial unit in Germany and Austria.

<p>The choice of the best model is based on Akaike's information criterion (AIC) in the package AICcmodavg from R (Mazerolle, 2016).</p

Number of alien plant species in relation to the dominant environment of each spatial unit.

<p>This elaboration is based on the intersection between data of alien plant species hotspots [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183691#pone.0183691.ref043" target="_blank">43</a>] and the land use composition in each 5.5 km x 5.5 km spatial unit extracted from CORINE land cover for Germany and Austria [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183691#pone.0183691.ref048" target="_blank">48</a>]. The box plots show medians, quartiles, 5- and 95-percentiles and extreme values.</p

data Morelli et al. 2017 JAE

List of Cuculidae species used in this study, common names, parasite behavior, number of host species, breeding distribution range and evolutionary distinctiveness (ED) score. The number of hosts for each cuckoo species was obtained from a literature review (Davies 2000; Erritzøe et al. 2012; Yang et al. 2012). The breeding distribution range was obtained from IUCN (IUCN & BirdLife International 2017) and ED score was downloaded from Edge of Existence (Zoological Society of London 2008)

Habitat-specific diversity in Central European birds

Bird species richness was highest in forest and urban habitat types, lower in grassland and wetland, and lowest in cropland. To investigate bird species richness patterns across different habitat types in Czechia, Central Europe. Data from a national breeding bird monitoring scheme in Czechia, based on mapping of positions of individual birds along transects, were used to express the number of species in habitat polygons. Each polygon was represented by one of the eight habitat types (coniferous, mixed and deciduous forest, cropland, grassland and other open habitat types, urban habitat, and wetland) obtained by detailed country-wide vegetation mapping. Species richness of individual polygons was related to polygon habitat type and area by linear mixed effects models, taking the surrounding land cover composition into account. Bird species richness was highest in forest, as predicted, and respective forest habitat types did not differ from each other. Urban habitat hosted a similar number of species as forest. Species richness varied greatly between different open habitat types: cropland was the most species-poor of all the habitat types considered, whereas grassland and other types of open habitats hosted significantly more species, albeit fewer than forests, and did not differ from wetland. Slopes of species-area relationships in respective habitat types largely followed the patterns in species richness. The observed patterns are partly driven by natural habitat characteristics, such as high vertical stratification of forest vegetation facilitating coexistence of a higher number of species. However, biogeography may also play a role, for example, and the relatively short time periods for colonization from Eastern European source areas may underpin lower bird species richness in grasslands. In addition, human interventions may drive the steep slope of the species-area relationship in forest, presumably caused by mosaic harvesting, as well as the shallow slope of this relationship in cropland and wetland, as a result of their intensive exploitation.</p

Amphibian Species traits and occurrence database in Turkey

Amphibian Species traits and occurrence database in Turke