Variation and plasticity in quantitative traits—By growing higher and developing longer and narrower leaves, Cyperus fuscus adopts a low-oxygen escape strategy characteristic of flood-tolerant species to avoid the negative effects of partial submergence. Our results suggest that differences in growth between the three habitat types – rivers, fishponds, and fish storage ponds – are both genetically fixed and caused by the growing conditions at the localities. In a controlled environment, plants originating from different habitats differed in both trait means and plasticities, indicating that populations have adapted to conditions at secondary habitats provided by fish farming during the last centuries. Plants from rivers performed better in general and responded better to high and fluctuating water levels than plants from secondary anthropogenic habitats. Seeds originally derived from the soil seed bank germinated faster than seeds originally derived from the surface population. Because of the experimental set-up, we suggest that this difference is not a result of differences in dormancy or maternal effects, but rather the result of short-term filtering of genotypes adapted to germinate under the particular conditions (such as temperature) during germination.
Publication: Böckelmann et al. (2017, Flora 234: 135-149).

Genetic variation—We developed 21 polymorphic SSR (microsatellite) markers for Cyperus fuscus.
Primers can be found in Böckelmann et al. (2015, Appl. Plant Sci. 3: 1500071).
Microsatellite analysis has been completed on >1400 individuals of Cyperus fuscus and will be complemented by Genotyping-by-Sequencing (GBS).
Publication: Böckelmann et al. (2020, Ecol. Evol. 10: 3620-3635)

Vegetation and implications for conservation—Despite that the vegetation of anthropogenic habitats harbors a great diversity of Isoëto-Nanojuncetea species (similar to that of riverine stands of Cyperus fuscus), C. fuscus plants from riverbanks exceed those from anthropogenic habitats in terms of genetic diversity, adaptation to flooding (lower cost of low-oxygen escape strategy), and fitness. This has important implications for conservation: It is necessary to preserve the dynamic riverine habitats if one wants to maintain all the adaptive potential of the species.
Publication: Kúr et al. (2021, Water 13: 1277)