Data from: Sensitivity to habitat fragmentation across European landscapes in three temperate forest herbs

Context. Evidence for effects of habitat loss and fragmentation on the
viability of temperate forest herb populations in agricultural landscapes
is so far based on population genetic studies of single species in single
landscapes. However, forest herbs differ in their life histories, and
landscapes have different environments, structures and histories, making
generalizations difficult. Objectives. We compare the response of three
slow-colonizing forest herbs to habitat loss and fragmentation and set
this in relation to differences in life-history traits, in particular
their mating system and associated pollinators. Methods. We analysed the
herbs’ landscape-scale population genetic structure based on
microsatellite markers from forest fragments across seven European
agricultural landscapes. Results. All species responded to reductions in
population size with a decrease in allelic richness and an increase in
genetic differentiation among populations. Genetic differentiation also
increased with enhanced spatial isolation. In addition, each species
showed unique responses. Heterozygosity in the self-compatible
Oxalis acetosella was reduced in smaller populations. The genetic
diversity of Anemone nemorosa, whose main pollinators are less
mobile, decreased with increasing spatial isolation, but not that of the
bumblebee-pollinated Polygonatum multiflorum. Conclusions. Our
study indicates that habitat loss and fragmentation compromises the
long-term viability of slow-colonizing forest herbs despite their ability
to persist for many decades by clonal propagation. The distinct responses
of the three species studied within the same landscapes confirm the need
of multi-species approaches. The mobility of associated pollinators should
be considered an important determinant of forest herbs’ sensitivity to
habitat loss and fragmentation.