Differential response to climatic variation of free-floating and submerged macrophytes in ditches
Article first published online: 26 APR 2011
© 2011 Blackwell Publishing Ltd
Volume 56, Issue 9, pages 1761–1768, September 2011
How to Cite
NETTEN, J. J. C., Van ZUIDAM, J., KOSTEN, S. and PEETERS, E. T. H. M. (2011), Differential response to climatic variation of free-floating and submerged macrophytes in ditches. Freshwater Biology, 56: 1761–1768. doi: 10.1111/j.1365-2427.2011.02611.x
- Issue published online: 4 AUG 2011
- Article first published online: 26 APR 2011
- (Manuscript accepted 31 March 2011)
- free-floating macrophytes;
- submerged macrophytes;
- North Atlantic Oscillation;
- The Netherlands
1. Experimental studies have indicated in freshwater ecosystems that a shift in dominance from submerged to free-floating macrophytes may occur with climate change because of increased water surface temperatures and eutrophication. Field evidence is, however, rare.
2. Here, we analysed long-term (26 years) dynamics of macrophyte cover in Dutch ditches in relation to Dutch weather variables and the North Atlantic Oscillation (NAO) winter index. The latter appears to be a good proxy for Dutch weather conditions.
3. Cover of both free-floating macrophytes and evergreen overwintering submerged macrophytes was positively related to mild winters (positive NAO winter index). On the other hand, high cover of submerged macrophytes that die back in winter coincided with cold winters (negative NAO winter index). Our results therefore suggest that the effect of weather on macrophyte species depends strongly on their overwintering strategy.
4. The positive relation of free-floating macrophytes with the NAO winter index was significantly stronger in ditches in organic soil than in those in inorganic soil. This may be because of increased nutrient loading associated with increased decomposition of organic matter and increased run-off to these ditches during mild wet winters.
5. Our results suggest that mild winters in a changing climate may cause submerged macrophytes with an evergreen overwintering strategy and free-floating macrophytes to outcompete submerged macrophytes that die back in winter.