Macrophyte assessment in European lakes : Diverse approaches but convergent views of ‘good’ ecological status
Laen...
Kuupäev
2018
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Elsevier
Abstrakt
The European Water Framework Directive has been adopted by Member States to assess and manage the ecological integrity of surface waters. Specific challenges include harmonizing diverse assessment systems across
Europe, linking ecological assessment to restoration measures and reaching a common view on ‘good’ ecological
status.
In this study, nine national macrophyte-based approaches for assessing ecological status were compared and
harmonized, using a large dataset of 539 European lakes. A macrophyte common metric, representing the
average standardized view of each lake by all countries, was used to compare national methods. This was also
shown to reflect the total phosphorus (r 2 = 0.32), total nitrogen (r 2 = 0.22) as well as chlorophyll-a
(r 2 = 0.35–0.38) gradients, providing a link between ecological data, stressors and management decisions.
Despite differing assessment approaches and initial differences in classification, a consensus was reached on how
type-specific macrophyte assemblages change across the ecological status gradient and where ecological status
boundaries should lie.
A marked decline in submerged vegetation, especially Charophyta (characterizing ‘good’ status), and an in-
crease in abundance of free-floating plants (characterizing ‘less than good’ status) were the most significant
changes along the ecological status gradient. Macrophyte communities of ‘good’ status lakes were diverse with
many charophytes and several Potamogeton species. A large number of taxa occurred across the entire gradient,
but only a minority dominated at ‘less than good’ status, including filamentous algae, lemnids, nymphaeids, and
several elodeids (e.g., Zannichellia palustris and Elodea nuttallii). Our findings establish a ‘guiding image’ of the
macrophyte community at ‘good’ ecological status in hard-water lakes of the Central-Baltic region of Europe.
This work was carried out under the WFD Common Implementation Strategy working group ECOSTAT work program. All participants in this exercise acknowledge support from national governments and regulatory agencies. We greatly acknowledge the contributions of the ECOSTAT representative and national experts. Helle Mäemets was supported by Estonian Target Financed Projects SF0362482s03 and SF0362483s03. Martin Søndergaard was supported by AQUACOSM (Network of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the Arctic to the Mediterranean), and the Centre for Water Technology (watec.au.dk).
This work was carried out under the WFD Common Implementation Strategy working group ECOSTAT work program. All participants in this exercise acknowledge support from national governments and regulatory agencies. We greatly acknowledge the contributions of the ECOSTAT representative and national experts. Helle Mäemets was supported by Estonian Target Financed Projects SF0362482s03 and SF0362483s03. Martin Søndergaard was supported by AQUACOSM (Network of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the Arctic to the Mediterranean), and the Centre for Water Technology (watec.au.dk).
Kirjeldus
Märksõnad
aquatic macrophytes, ecological status, eutrophication, indicator species, nutrients, phosphorus, species richness, Water Framework Directive, articles