Genotypic and phenotypic distinctness of restored and indigenous populations of Pimpinella saxifraga L. 8 or more years after restoration.

The recovery of altered or damaged ecosystems demands large-scale reintroductions of seeds. In the past, ecological restoration in Germany was carried out with non-local seeds of naturally occurring species. We here analysed whether the genetic pattern of the introduced non-local seeds (R = restored) of Pimpinella saxifraga are still detectable several years after application and whether the phenotype differs from that of the regional gene pool (I = indigenous) of the species. We collected material from individuals of R and I sites, conducted a common garden experiment and tested for genetic, morphological and phenotypic differences. In a cutting experiment we investigate treatment effects on indigenous and restored populations. At all investigated sites we only found P. saxifraga individuals with comparatively similar genome sizes. The population genetic analysis revealed two large and quite distinct molecular clusters, separating indigenous and restored individuals along the first axis. None of the vegetative, but two of the reproductive fitness parameters differed between individuals of the R and I sites. Cutting always had a significant influence on all analysed vegetative and reproductive fitness parameters, regardless of the individuals' origin. The effects of mowing always mask origin-specific characteristics, which then disappear. Genotypic coexistence reduces the availability of niches for the local genotype and may eventually lead to genotypic competition or introgression. We therefore recommend not to use non-local genotypes of this species in the region. Instead, we recommend using the genetically diverse local genotypes of P. saxifraga for restoration purposes.