No abstract

For restoration purposes, nature conservation generally enforces the use of local seed material based on the “local‐is‐best” (LIB) approach. However, in some cases recommendations to refrain from this approach have been made. Here we test if a common widespread species with no obvious signs of local adaptation may be a candidate species for abandoning LIB during restoration. Using 10 microsatellite markers we compared population genetic patterns of the generalist species Daucus carota in indigenous and formerly restored sites (nonlocal seed provenances). Gene diversity overall ranged between H e = 0.67 and 0.86 and showed no significant differences between the two groups. Hierarchical AMOVA and principal component analysis revealed very high genetic population admixture and negligible differentiation between indigenous and restored sites (F CT = 0.002). Moreover, differentiation between groups was caused by only one outlier population, where inbreeding effects are presumed. We therefore conclude that the introduction of nonlocal seed provenances in the course of landscape restoration did not jeopardize regional species persistence by contributing to inbreeding or outbreeding depressions, or any measurable adverse population genetic effect. On the basis of these results, we see no obvious objections to the current practice to use the 10‐fold cheaper, nonlocal seed material of D. carota for restoration projects.

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.

For restoration purposes nature conservation preferably requests the use of local seed sources based on the “local-is-best” (LIB) approach. However, counter-arguments against this usage are potential benefits by increased variation, which could be beneficial especially in times of global change. We here investigate intraspecific morphological variability of one of the most common herbaceous, insect pollinated and zoochorous plants from seed mixtures used for landscape restoration processes in central Europe, the wild carrot, Daucus carota L. (Apiaceae). Our results show that D. carota features no vegetative but two generative characters that significantly differed among plants originating from seeds of natural (I) and restored (R) sites. We could show that effects of mowing always overlay origin-specific characteristics. The earlier genetic analysis did not support a regional provenance concept for restoration purposes, while slight differences in phenological parameters related to fitness pinpoint to ‘mix and match-admixture provenancing’ as a compromise strategy.