As a consequence populations consist of a subset of the original founding clones. Because of the absence of sexual recruitment, and thus of the recruitment of potentially beter adapted clones, populations may be very vulnerable for human induced changes in the environment, such as global warming and eutrophication. Global warming, among other factors, changes the length of the growing season. If clones are adapted to local climatic conditions, global warming might result in the wrong timing of e.g. shoot emergence, flowering and die-back of shoots in autumn.
Eutrophication causes the disappearance of the waterward side of populations.
As a result, eutrophication might result in the loss of clones adapted to deep water. Achievements 1996 Seeds and rhizomes were collected along transects at the water- and landward side of 9 european populations. Rhizomes were propagated in outdoor containers for further use. A greenhouse experiment was performed during 8 weeks to study morphological and growth differences of seedlings subjected to two different levels of nutrient supply. Both experiments are finished, however data have not yet been processed.