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 ..., The allele data originate from 42, 34 and 36 populations of Anemone nemorosa, Oxalis acetosella and Polygonatum multiflorum, respectively, sampled in seven 5 x 5 km² landscape windows across Europe (North France, Belgium, West Germany, East Germany, South Sweden, Central Sweden,  Estonia). A population is defined as a spatially distinct group of shoots >100 m apart from other shoots. Typically, populations covered the whole forest patch, but were in some cases restricted to certain parts of a forest patch if habitat conditions were heterogeneous. From each plant population, we randomly collected leaf material from up to 20 flowering, healthy individuals spread across the population for DNA extraction. A minimum distance of 10 m between selected plants was set to avoid sampling of clones. Fewer than 20 samples per population were available in 29.5% of the populations either due to genotyping failures or due to a very small population size. Leaf samples were dried and stored using sili..., See the README file.