Article 2 of the Convention on Biological Diversity defines an ecosystem as ‘a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit’ and a habitat as ‘the place or type of site where an organism or population naturally occurs’ (UN, 1992a). We follow the approach adopted by the UK National Ecosystem Assessment and classify ecosystems using broad habitat types (UK National Ecosystem Assessment, 2011). For this project, habitat types have been defined according to the MAES typology (Maes et al, 2013) and the European Nature Information System (EUNIS).
EUNIS brings together data on species and habitats from several European databases and organisations (http://eunis.eea.europa.eu/index.jsp). It is part of the Biodiversity data centre of the European Environment Agency and aids implementation of EU biodiversity strategies and the General Union Environment Action Programme to 2020 – Living well, within the limits of our planet (EC, 2014). The EUNIS habitat classification covers both natural and artificial pan-European habitats and groups them into 11 broad categories:
- Marine habitats
- Coastal habitats
- Inland surface waters
- Mires, bogs and fens
- Grasslands and lands dominated by forbs, mosses or lichens
- Heathland, shrub and tundra
- Woodland, forest and other wooded land
- Inland unvegetated or sparsely vegetated habitats
- Regularly or recently cultivated agricultural, horticultural and domestic habitats
- Constructed, industrial and other artificial habitats
- Habitat complexes
This hierarchical classification, which was revised in 2012, divides the 11 broad habitat categories into 5282 distinct habitat types (http://www.eea.europa.eu/themes/biodiversity/eunis/eunis-habitat-classification).
The MAES project, which is mandated to coordinate and oversee Action 5 of the EU 2020 Biodiversity Strategy, has proposed a typology that distinguishes 12 main ecosystem types based on the higher levels of the EUNIS Habitat Classification (Table 2.2). The MAES typology was applied in six pilot studies covering forests, agriculture, fresh waters and marine systems. It was concluded that, whereas the MAES typology worked well for forests, questions were raised about the appropriateness of combining arable land and permanent crops into a single category (i.e. cropland). The challenges of defining boundaries for freshwater systems was highlighted and several weaknesses with the marine typology were identified that require further refinement (e.g. typology solely based on bathymetry due to limited mapping information) (Maes et al, 2014).
The MAES typology is used in the current project, with the slight modification that the category ‘Rivers and lakes’ is subdivided into standing (EUNIS C1) and running (EUNIS C2) waters for the ‘Down the drain’ case study and coastal wetlands (i.e. saltmarshes and saline reedbeds; EUNIS A2.5) are separated out from the ‘marine inlets and transitional waters’ category for the oil refinery case study.
Table 2.2: Proposed MAES typology of European habitats and corresponding EUNIS habitat code (Appendix B). Adapted from Maes et al (2013)
X01: Estuaries; X02: Saline coastal lagoons; X03: Brackish coastal lagoons; A1: Littoral rock and other hard substrata; A2: Littoral sediment; A3: Infralittoral rock and other hard substrata; A4: Circalittoral rock and other hard substrata; A5: Sublittoral sediment; A6: Deep-sea bed; A7: Pelagic water column.