European river plant communities: the importance of organic pollution and the usefulness of existing macrophyte metrics

Abstract

The macrophyte surveys undertaken as part of the EU-funded STAR project are a unique resource allowing aquatic plant communities to be studied at a Pan-European scale (211 stream sites with macrophytes in 14 countries). Using this dataset, we examined the influence of organic pollution in relation to other environmental correlates of river plant community variation across Europe. We examined the relationships between several existing macrophyte metrics and nutrient enrichment, and we also explored the possibility of developing a pan-European macrophyte-based assessment system. We showed that trophic (nutrient) status is an important driver of aquatic plant communities in European rivers. We found that while most existing macrophyte metrics are useful, none can be applied at a pan-European scale in their current form. Our attempt to redesign the Mean Trophic Rank (MTR) index by the addition of further species, and the re-scoring of existing species, resulted in a considerable improvement in the relationship between MTR scores and nutrient variables. We conclude that an enlarged core group of macrophyte species can form part of an improved pan-European macrophyte-based bioassessment system, although regional modifications may be required to adequately describe the nutrient status of certain stream types.

Complex environmental gradients predict distributions of river-dependent plants in eastern Australia

“…This may seem surprising because the composition of assemblages of running-water macrophytes has often been regarded as strongly indicative of a river's nutrient status, especially in Europe (e.g. Ali et al 1999;Schneider and Melzer 2003;Szoszkiewicz et al 2006). However, some European studies have found only weak relationships between concentrations of nitrogen and phosphorus and macrophyte indices (e.g.…”

Towards harmonization of ecological quality classification: establishing common grounds in European macrophyte assessment for rivers

“…Several previous studies have attempted to compare indicator scores of individual plant species across different river macrophyte assessment methods used within Europe (e.g. Szoszkiewicz et al, 2006a;Schneider, 2007), but such studies have focussed exclusively on trophic indices, have generally operated across types, or within very broad types (e.g. upland versus lowland) and have therefore avoided issues of benchmarking indices against concepts of minimal impact.…”

“…Biogeographical zone, catchment geology and stream hydrology establish the large-scale framework influencing occurrence and abundance of macrophytes (Lacoul & Freedman, 2006). Since most of these local factors are susceptible to anthropogenic alteration, macrophytes are potentially effective bioindicators that respond to various human pressures such as physical stream disturbance and alteration (Baattrup-Pedersen & Riis, 1999, 2004, river pollution (Schneider & Melzer, 2003;Hilton et al, 2006;Szoszkiewicz et al, 2006a), disruption of the riparian integrity (Ferreira et al, 2005) or general deterioration . In summary, these studies reveal some general patterns of community change under human influence: Anthropogenic disturbance fosters a decline in species richness especially of submerged macrophytes, the reduction of oligotrophic and large, slow growing species, leading to fragmentation of populations and rare species threatened by extinction, and favours macrophyte taxa with high growth capacity and efficient dispersal.…”

Distribution and Bioindication Role of Aquatic Bryophytes in Bulgarian Rivers

“…Four moss species: Brachythecium rivulare, Fontinalis antipyretica, Leptodictyum riparium and Platyhypnidium riparioides were chosen in the current study because: (i) they have high sensibility to different environmental stresses; (ii) they are strictly aquatic species; (iii) have wide distribution in Bulgaria; (iv) their taxonomy is relatively easy. (18). Platyhypnidium riparioides has score (5) only in MTR.…”