Results

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).