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Class I - emphemeral ponds.

Central zone represented by low-prairie vegetation (Poa pratensis, Solidago altissima, etc.).
Subclasses: None
Cover types: 1, 2, 3, and 4.

Class II - temporary ponds.

Central zone represented by wet-meadow vegetation (generally fine-stemmed grasses and sedges with associated forbs).
Subclasses:

A - Fresh	Poa palustris, Boltonia latisquama, etc.
B - Slightly Brackish	Hordeum jubatum, Calamagrostis inexpansa, etc.

Cover types: 1, 2, 3, and 4.

Class III - seasonal ponds and lakes.

Central zone represented by shallow-marsh vegetation (moderately coarse grasses and sedges with associated forbs).
Subclasses:

A - Fresh	Carex atherodes, Glyceria grandis, etc.
B - Slightly Brackish	Scolochloa festucacea, Eleocharis palustris, etc.
C - Moderately Brackish	Alisma gramineum, Beckmannia syzigachne, etc.

Cover types: 1, 2, 3, and 4.

Class IV - semipermanent ponds and lakes.

Central zone represented by deep-marsh vegetation (relatively coarse marsh emergents or associated submerged aquatics).
Subclasses:

A - Fresh	Scirpus heterochaetus, etc.
B - Slightly Brackish	Typha spp., Scirpus acutus, etc.
C - Moderately Brackish	Scirpus acutus, etc.
D - Brackish	Scirpus paludosus, Scirpus acutus, etc.
E - Subsaline	Scirpus paludosus, etc.

Cover types: 1, 2, 3, and 4

Class V - permanent ponds and lakes.

Central area represented by permanent-open-water zone (devoid of emergent vegetation, but submerged vegetation, particularly Ruppia occidentalis, often present).
Subclasses (based on species composition of peripheral zones):

B - Slightly Brackish	Typha spp., Scolochloa festucacea, etc.
C - Moderately Brackish	Scirpus acutus, Hordeum jubatum, etc.
D - Brackish	Scirpus paludosus, Scirpus americanus, etc.
E - Subsaline	Puccinellia nuttalliana, Salicornia rubra, etc.

Cover Types: 3 and 4

Class VI - alkali ponds and lakes.

Central area represented by intermittent-alkali zone (devoid of emergent vegetation; Ruppia maritima often common).
Subclasses: None
Cover types: 3 and 4

Class VII - fen ponds.

Central zone represented by fen vegetation (Glyceria striata, Carex aquatilis, etc.).
Subclasses: None
Cover types: 1, 2, and 3.

This classification system was tested repeatedly during intensive field studies in North Dakota and was found to be both expedient and realistic. Observations during exploratory trips through other parts of the glaciated prairie region (including the Prairie Provinces of Canada and States adjoining North Dakota) indicate that it is an effective method for the entire region. In certain local areas, particularly those near the margin of the glaciated prairie region, minor modifications may be required. A number of Federal and State and Provincial agencies in the United States and Canada have also field-tested the classification system. Their findings to date generally support the direct application of this system in their wetland investigations.