MODELLING AQUATIC BRYOPHYTES AND OTHER MACROPHYTES IN DETERIORATING RIVERS

Bryophytes are an integral and important part of aquatic vegetation and biodiversity especially in river rapids and riffles. We modelled aquatic macrophyte data, some 50 bryophyte and 150 tracheophyte taxa, in 295 river sites with standardized sampling to estimate ecological quality. Using RIVPACS type approach we recognized 11 distinct plant communities in natural or near natural state. Size and soil of catchment area and latitude could be used to characterize natural macrophyte communities in pools and riffles. Based on reference communities we estimated ecological quality of impacted sites utilizing two indices: taxonomic completeness (O/E-taxa) and percent model affinity (PMA). Bryophytes in rapids alone can be used in ecological classification of rivers, though most reliable results are achieved by studying all aquatic plants in both riffles and pools. To assess changes in biodiversity we further modelled how species frequencies change due to environmental loading and disturbance, with a larger data of 780 sites and 124 bryophyte taxa. We paid special attention to more common proper aquatics with high confidence interval in the model. Of these, four species have clearly lower frequency even in sites of good ecological status than in reference sites whereas three were more frequent. Sites in high ecological status naturally did not differ from refence sites. This indicates that the target of the European environmental policy, good ecological status of all water bodies, is not good enough to maintain aquatic biodiversity

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Krister Karttunen, Finnish Environment Institute (krister.karttunen@syke.fi)

Authors:

Krister Karttunen, Finnish Environment Institute  (krister.karttunen@syke.fi)

Anna Suuronen, Finnish Environment Institute  (anna.suuronen@syke.fi)

Jukka Aroviita, Finnish Environment Institute  (jukka.aroviita@syke.fi)

Heikki Mykrä, Finnish Environment Institute  (heikki.mykra@syke.fi)

Annika Vilmi, Finnish Environment Institute  (annika.vilmi@syke.fi)