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Biology subjects

Liepelt, S.

Publications and source records attributed to Liepelt, S..

7 recordsLinked to original sources

Rapid adaptive evolution in restored populations of a perennial plant

Restored plant populations often face novel environmental challenges because degraded restoration sites typically differ from natural habitats. The success of ecosystem restoration may therefore depend on whether restored plant populations can adapt rapidly to these novel conditions. Yet, rapid adaptive evolution during restoration remains rarely studied. Here, we tested for rapid adaptation in Galium wirtgenii, a perennial herb, within restored alluvial grasslands. Sites were restored 20 years ago by transferring hay from nearby ancient semi-natural meadows. Compared to the semi-natural donor meadows, restored sites are more productive and are mown two to three months earlier. We collected seeds from 571 mother plants from 48 restored and 18 semi-natural sites and grew their offspring in a common garden over three years. To test for differences in regeneration after mowing, we included a clipping treatment when plants were in full blossom. Plants from restored sites flowered earlier than plants from semi-natural sites, and this difference persisted across all three years, consistent with a heritable evolutionary response to earlier mowing allowing plants at restored sites to complete reproduction before mowing. Plants from restored sites also grew more slowly in early life stages, but this effect disappeared later, suggesting maternal effects rather than genetic differentiation. We did not detect differences in regeneration after clipping, likely because regrowth rarely results in viable seeds, providing little fitness advantage. In summary, we found evidence for rapid adaptation to novel environmental conditions in restored sites, likely contributing to successful establishment of Galium wirtgenii populations in the restored grasslands.

evolutionary biology↗

Environmental drivers of heritable trait variation and lag of adaptation to climate in Hordeum murinum

1. Most plant species are genetically differentiated among populations, often reflected by phenotypic trait variation that corresponds to local adaptation. Yet the strength of local adaptation and heritable contribution to phenotypic traits vary across traits, species, and environments. Additionally, climate change is rapidly altering environmental conditions, and the climate may shift faster than populations can adapt or track the change via dispersal, resulting in adaptive lags. However, it remains unclear how widespread such adaptive lags are across plant species. 2. We focused on Hordeum murinum, an annual ruderal grass widespread in Europe. We combined continental-scale in situ measurements of 2070 plants across 207 populations with common garden experiments across two contrasting climates and two soil types to disentangle heritable variation from phenotypic plasticity and assess potential adaptive lags under climate change. 3. We found that heritable variation was pronounced in developmental traits, particularly flowering time and plant height, while seed weight, reproductive investment and SLA showed intermediate heritable contribution, and flag leaf area and total biomass were primarily plastic. Heritable trait variation was strongly associated with temperature at the populations origin, and trait clines were consistent with in situ patterns, suggesting that temperature is the main driver of genetic differentiation in H. murinum. However, we detected that fitness peaked in populations originating from warmer climates, indicating that evolutionary responses may not keep pace with rapid environmental shifts. 4. Synthesis: Our results highlight that H. murinum harbors substantial heritable variation, shaped primarily by temperature. However, the pace of evolutionary change may be insufficient to track ongoing climate change, leaving populations potentially vulnerable to future environmental conditions.

ecology↗

Small stream restoration increases habitat and plant diversity across scales

A majority of stream restoration efforts in central Europe focus on streams that are less than five meters wide. Restoration aims to increase structural complexity, thereby enhancing habitat heterogeneity, promoting biodiversity, and reestablishing aquatic-terrestrial linkages that can drive responses in adjacent terrestrial communities. However, the effects of small stream restoration on terrestrial biodiversity remain poorly understood because research focuses mainly on large rivers. Here, we investigated the effects of restoration on the structural complexity of the stream channel as well as the terrestrial habitat and plant diversity on a local and landscape scale across 55 small streams in an agricultural landscape. We compared restored stream sections with non-restored ones that were similar to the conditions before restoration. We also assessed how restored sections changed over time since restoration. Restored stream sections showed a higher stream structural complexity and habitat diversity, both of which are targets of active restoration measures. Restoration also increased riparian plant diversity, both directly and indirectly through structural complexity and habitat diversity. Although time since restoration did not influence structural complexity, it drove successional changes in plant communities that became increasingly associated with wetland habitat conditions. Our results demonstrate that small stream restoration effectively increases floodplain habitat and plant diversity in agricultural landscapes, primarily by enhancing water availability in the floodplain. Restoration actions on small streams support biodiversity if they improve stream channel complexity, connect the stream with its floodplain, and create floodplain habitats.

ecology↗

Beyond viability: Seed ageing alters development and phenology of adult plants

O_LIStored seeds are crucial repositories of plant genetic diversity. However, long-term storage inevitably causes seed deterioration and loss of viability, and chemical processes within the seeds during storage can influence germination and seedling establishment. Emerging evidence suggests that seed ageing can also affect traits of adult plants, yet the extent to which this phenomenon is relevant across species, particularly for wild plant species with high genetic variation, remains unclear. C_LIO_LITo address this, we focused on 14 grassland species and subjected their seeds to simulated long-term storage by exposing them to artificial ageing conditions (60% rH, 45{degrees}C). We then compared plants grown from the aged seeds with plants from fresh seeds in a common garden experiment. C_LIO_LIArtificially aged seeds germinated later, the developing seedlings had lower survival rates and reduced growth. Adult plants grown from aged seeds flowered later, produced fewer flowers, and had less biomass by the end of the first vegetation period than those from fresh seeds. The effect of the ageing treatment varied between species, but the trend was overall significant across species, with minor differences between perennials and annuals. Interestingly, in perennial plants, the effects vanished or were inverted in the second growing season, with plants growing from aged seeds flowering earlier and producing more biomass. C_LIO_LISynthesis. Our results show that seed storage affects seedling performance, plant growth, and flowering phenology. These direct storage effects should be considered when using stored seeds for species conservation, ecosystem restoration, or evolutionary research relying on stored seeds. C_LI

plant biology↗

Large interspecific and intraspecific variation in seed longevity in storage

PremiseConservation seed banks are essential for ex-situ plant conservation, but stored seeds slowly deteriorate and lose viability. Seed longevity in storage is determined by the initial seed viability and the rate of seed viability loss. The rate of seed viability loss in storage varies between species, and there is possibly also some variation between populations or even genotypes within species. However, the extent of this intraspecific variability and its drivers remain unclear. MethodsWe investigated both inter- and intraspecific variability in seed longevity and its predictors in 41 common grassland species and 188 seed accessions from across Europe. We exposed the seeds to artificial ageing conditions (60% RH, 45{degrees}C) and used probit analysis to obtain the rate of seed viability loss ({sigma}) as a measure of seed longevity. We then related {sigma} to both accession- and species-specific factors. Key resultsSeed longevity ({sigma}) varied significantly among accessions within 58% of the species, and the probability of detecting such intraspecific differences increased with the number of accessions available for a given species. This suggests that within-species variation in seed longevity is widespread. Accession-specific predictors explained only 14.4% of the within-species variability. Specifically, seed longevity increased with the mean annual temperature at the accession origin and decreased with the accession-specific seed weight. Across species, seed longevity differed among plant families but was unrelated to seed weight or seed chemical composition. ConclusionsOur findings highlight substantial within-species variation in seed longevity in storage, which, however, is difficult to predict.

ecology↗

Predominance of clonal propagation conceals extinction risks of the highly endangered floodplain herb Cnidium dubium

Habitat loss and degradation due to human-induced landscape alterations are considered to be a major threat to biodiversity. The decline of biodiversity may occur with a time delay leading to a so called extinction debt. Therefore, determining extinction risks and conservation status is not always straightforward. Several life history traits might play a role for the accumulation of an extinction debt. Thus, perennial plant species capable of vegetative propagation might be able to persist temporarily in degraded habitats even though sexual and evolutionary processes are effectively halted. We studied Cnidium dubium, which occurs in scattered patches along river corridors in Central Europe and is critically endangered in Germany. It is a perennial species which is able to propagate clonally. Our aims were to reconstruct demographic processes regarding clonal propagation and gene flow along 400 km of river stretch and with respect to the position in the flooplain, i.e. before or behind dykes. We also wanted to determine whether there is evidence for an extinction debt in C. dubium and to use our insights for conservation recommendations. For this, we used nuclear microsatellites and maternally inherited chloroplast DNA markers and applied a systematic grid based sampling strategy for small scale geographic structures. We observed a high level of clonal propagation. In 935 analysed plants we observed only 121 different genotypes and of 50 studied patches of C. dubium the majority (31 patches) consisted of one single genotype each. Patch size and position were correlated with clonal diversity. Large patches and patches behind dykes exhibited higher clonal diversity. There was no evidence for a large scale genetic substructuring of the study area and no differences in overall genetic diversity between upstream and downstream patches as well as between patches before and behind the dykes. High levels of heterozygosity and a high number of 18 chloroplast DNA haplotypes togetherwith a slightly elevated inbreeding coefficient (Fis) point toward a high level of ancestral polymorphism in an out of equilibrium population due to high levels of clonal propagation and low levels of gene flow and recombination. Therefore, we assume that an extinction debt is present in C. dubium. As a management strategy, we propose to transplant ramets between multiple patches to increase the number of mating partners and therefore restore sexual reproduction.

ecology↗

Linking Dendroecology And Association Genetics: Stress Responses Archived In Tree Rings Associate With SNP Genotypes In Abies alba (Mill.)

O_LIGenetic association studies in forest tress would greatly benefit from information on tree response to environmental stressors over time. Dendroecology can close this gap by providing such time series measurements. Here, we jointly analyzed dendroecological and genetic data to explore the genetic basis of resistance, recovery and resilience to episodic stress in silver fir.\nC_LIO_LIWe used individual level tree-ring data to characterize the growth patterns of surviving silver fir (Abies alba) during the forest dieback in the 1970s and 1980s in Central Europe and associated them with SNPs in candidate genes.\nC_LIO_LIMost trees at our study sites in the Bavarian Forest experienced severe growth decline from 1974 until the mid-1980s, which peaked during the drought year of 1976. Using the machine learning algorithm random forest, we identified 15 candidate genes that were associated with the variance in resistance, resilience and recovery among trees in this period.\nC_LIO_LIWith our study we show that the unique possibility of phenotypic time series archived in tree-rings are a powerful resource in genetic association studies. We call for a closer collaboration of dendroceologists and forest geneticists to focus on integrating individual tree level signals in genetic association studies in long lived trees.\nC_LI

ecology↗