Table 2.

Metrics included in the macrophyte-based lake assessment systems. ↓ metrics decrease along ecological status gradient; ↑ metrics increase along ecological status gradient.

	Macrophyte state variable
Member State	Abundance	Structure	Diversity
Belgium Flanders	Area-weighted abundance of submerged vegetation↑↓	Area-weighted type-specific species composition index↓ Area-weighted disturbance index↑	Diversity of macrophyte growth forms↓
Denmark	Maximum colonization depth of submerged macrophytes in deep lakes↓ Coverage of submerged macrophytes (% of total lake area) in shallow lakes↓	Presence of species indicative of nutrient poor conditions↓
Estonia	Maximum depth of colonization of submerged macrophytes↓	Relative abundance of indicator taxa (Potamogeton perfoliatius, P. lucens) or groups (charophytes, bryophytes, lemnids)↓↑ Abundance of large filamentous algae↑
Germany	Maximum depth of macrophyte stands ↓	Reference Index↓ Dominant stands of the eutrophication indicator taxa↑
Latvia	Maximum depth of colonization of submerged macrophytes↓	Relative abundance of indicator taxa (Chara, Ceratophyllum or Zannichellia, Potamogeton perfoliatius, P. lucens) or groups (charophytes, bryophytes, lemnids)↓↑ Abundance of large filamentous algae↑
Lithuania	Maximum depth of macrophyte stands↓	Reference Index↓ Dominant stands of the eutrophication indicator taxa↑
Netherlands	Relative cover of growth forms↓	Indicator species metrics↓
Poland	Colonization index (ratio of vegetated area and area where water is shallower than 2.5 m)↓		Pielou’s index (syntax level)↓
UK	Mean percent cover of hydrophytes↓	Lake Macrophyte Nutrient Index (LMNI)↑ Relative cover of filamentous algae↑	Number of hydrophyte taxa↓ Number of functional groups↓