Fig. 2. Species richness (A) and abundance (B) of the ecosystem service
providers in invaded (orange) and not invaded (blue) agricultural land.
Means with 95% confidence intervals are shown. Abundance of plants
represents the mean cover of native plants per plot, for insect
pollinators it is the mean number of individuals per 200 m transect, for
ants it is the number of their nests in a 100 m2 plot
and for birds it is the number of breeding pairs in a habitat patch.
Data for vascular plants, bees, butterflies, and hoverflies recalculated
from Moroń et al. (2009), data for ants taken from Lenda et al. (2013)
and data on birds are from Skórka et al. (2010). Unpublished data from
bird mapping in abandoned fields (both invaded and not invaded by
goldenrods) and managed fields were used to demonstrate how different
proportions of spared land may affect bird species richness (C) and
number of breeding pairs (D) in landscapes with no invasion of
goldenrods (blue) and under the invasion (orange). Virtual landscapes of
about 1 km2 were created from managed fields and
abandoned fields (spared land) by a random selection of the real data.
The proportion of spared land varied from 0 (only managed fields) to
100% (only abandoned fields) for two scenarios (i.e., invaded and not
invaded landscape). For each cover of spared land, 100 landscapes were
simulated. Curves are general additive models fitted to the data
(details in Supplementary material 1).