THE NATURAL COMMUNITIES OF VIRGINIA
CLASSIFICATION OF ECOLOGICAL COMMUNITY GROUPS
Second Approximation (Version 2.5)
Information current as of February, 2012
SUMMARY OF CHANGES TO ECOLOGICAL GROUP CLASSIFICATION SINCE THE FIRST APPROXIMATION
Since completion of the First Approximation (Fleming et al. 2001), analysis of several large, regional datasets and ongoing inventory of vegetation across the state have led to a number of changes to the Ecological Group Classification. These changes have been formally implemented in this Second Approximation (currently version 2.2) to increase the clarity of the classification by merging closely related groups and altering a number of names to better reflect the gross physiognomic characteristics and geographic distributions of included vegetation types.| First Approximation Unit | Disposition in Second Approximation |
|---|---|
| Fraser Fir – Red Spruce Forests | merged with the two following groups into a new SPRUCE-FIR FORESTS group |
| Southern Appalachian Red Spruce Forests | merged with the preceding and following groups into a new SPRUCE-FIR FORESTS group |
| Central Appalachian Red Spruce Forests | merged with the two preceding groups into a new SPRUCE-FIR FORESTS group |
Southern Appalachian Grassy Balds |
merged with the following group into a new SOUTHERN APPALACHIAN SHRUB AND GRASS BALDS group |
| Southern Appalachian Shrub Balds | merged with the preceding group into a new SOUTHERN APPALACHIAN SHRUB AND GRASS BALDS group |
| Southern Appalachian Northern Hardwood Forests | merged with the following group into a new NORTHERN HARDWOOD FORESTS group |
| Central Appalachian Northern Hardwood Forests | merged with the preceding group into a new NORTHERN HARDWOOD FORESTS group |
| (not represented) | a new HIGH-ELEVATION COVE FORESTS group was added to represent high-elevation communities previously included in the Rich Cove and Slope Forests and Acidic Cove Forests groups |
Montane Pine Barrens |
merged into the Pine – Oak / Heath Woodlands group |
Eastern Hemlock Forests |
name changed to EASTERN HEMLOCK-HARDWOOD FORESTS |
Eastern Arborvitae Slope Forests |
name changed to NORTHERN WHITE-CEDAR SLOPE FORESTS |
| Montane Oak – Hickory Forests | Concept broadened and name changed to MONTANE MIXED OAK AND OAK – HICKORY FORESTS |
| Mixed Oak / Heath Forests | merged with the following group into a new OAK / HEATH FORESTS group |
Chestnut Oak Forests |
merged with the preceding group into a new OAK / HEATH FORESTS group |
| Montane Acidic Woodlands | name changed to MOUNTAIN / PIEDMONT ACIDIC WOODLANDS |
| Piedmont / Mountain Basic Woodlands | name changed to MOUNTAIN / PIEDMONT BASIC WOODLANDS |
| Ultramafic Woodlands | merged with the Ultramafic Barrens group into a new ULTRAMAFIC WOODLANDS AND BARRENS group |
| Acidic Oak-Hickory Woodlands and Savannas | merged with the following group into a new OAK-HICKORY WOODLANDS AND SAVANNAS group |
| Basic Oak-Hickory Woodlands and Savannas | merged with the preceding group into a new OAK-HICKORY WOODLANDS AND SAVANNAS group |
Xeric Calcareous Cliffs |
merged with the two following groups into a new MOUNTAIN / PIEDMONT CALCAREOUS CLIFFS group. |
Mesic Calcareous Cliffs |
merged with the preceding and following groups into a new MOUNTAIN / PIEDMONT CALCAREOUS CLIFFS group. |
Piedmont / Mountain Basic Cliffs |
merged with the two preceding groups into a new MOUNTAIN / PIEDMONT CALCAREOUS CLIFFS group. |
Piedmont / Mountain Acidic Cliffs |
name changed to MOUNTAIN / PIEDMONT ACIDIC CLIFFS |
| Ultramafic Barrens | merged with the Ultramafic Woodlands group into a new ULTRAMAFIC WOODLANDS AND BARRENS group |
Moss / Lichen Boulderfields |
name changed to LICHEN / BRYOPHYTE NONVASCULAR BOULDERFIELDS AND OUTCROPS |
Maritime Scrub |
name changed to MARITIME DUNE SCRUB |
Maritime Evergreen Forests |
merged with the two following groups into a new MARITIME UPLAND FORESTS group. |
Maritime Loblolly Pine Forests |
merged with the preceding and following groups into a new MARITIME UPLAND FORESTS group. |
Maritime Mixed Forests |
merged with the two preceding groups into a new MARITIME UPLAND FORESTS group. |
| Coastal Plain / Piedmont Bottomland Forests | split into two new groups: COASTAL PLAIN / PIEDMONT FLOODPLAIN FORESTS and COASTAL PLAIN / PIEDMONT SWAMP FORESTS. In 2011, this group was restored and the two new groups above re-merged. |
Coastal Plain Semipermanent Impoundments |
merged with the Piedmont / Mountain Semipermanent Impoundments group into a new SEMIPERMANENT IMPOUNDMENTS group |
Piedmont / Mountain Bottomland Forests |
name changed to PIEDMONT / MOUNTAIN FLOODPLAIN FORESTS |
Piedmont / Low Mountain Alluvial Forests |
merged with the following group into a new PIEDMONT / MOUNTAIN ALLUVIAL FORESTS group. In 2011, the name of this group was changed to PIEDMONT / MOUNTAIN SMALL-STREAM ALLUVIAL FORESTS |
Montane Alluvial Forests |
merged with the preceding group into a new PIEDMONT / MOUNTAIN ALLUVIAL FORESTS group |
Piedmont / Mountain Semipermanent Impoundments |
merged with the Coastal Plain Semipermanent Impoundments group into a new SEMIPERMANENT IMPOUNDMENTS group |
| River-Scour Woodlands | merged into the ROCKY BARS and SHORES Group |
| Montane Basic Seepage Swamps | name changed to MOUNTAIN / PIEDMONT BASIC SEEPAGE SWAMPS |
| High-Elevation Seeps | concept broadened and name changed to MONTANE WOODLAND SEEPS. |
| Mountain Ponds | concept broadened and name changed to MONTANE DEPRESSION WETLANDS |
| Shenandoah Valley Sinkhole Ponds | merged with the former Mountain Ponds group into a broader MONTANE DEPRESSION WETLANDS group |
| Calcareous Fens and Seeps | merged with the following group into a new CALCAREOUS FENS group |
| Wet Prairies and Prairie Fens | merged with the preceding group into a new CALCAREOUS FENS group |
| Mafic Woodland Seeps | merged into the Mafic Fens and Seeps group |
| Natural Lake Draw-Down Shores | merged into the Coastal Plain Depression Wetlands group |
| Coastal Plain Depression Ponds | name changed to COASTAL PLAIN DEPRESSION WETLANDS |
Non-Riverine Pine-Hardwood Forests |
merged with the following two groups into a new NON-RIVERINE FLATWOODS AND SWAMPS group |
| Non-Riverine Wet Hardwood Forests | merged with the preceding and following groups into a new NON-RIVERINE FLATWOODS AND SWAMPS group |
| Non-Riverine Swamp Forests | merged with the preceding two groups into a new NON-RIVERINE FLATWOODS AND SWAMPS group |
Longleaf Pine and Mixed Pine Flatwoods |
deleted; vegetation formerly placed in this group is now considered part of the Pine / Scrub Oak Sandhills group |
Coastal Plain Basic Seepage Swamps |
name changed to COASTAL PLAIN / PIEDMONT BASIC SEEPAGE SWAMPS |
| Streamhead Pocosins | Merged into NON-RIVERINE FLATWOODS AND SWAMPS group |
Interdune Wet Pine Woodlands |
merged into the Maritime Swamp Forests group |
Estuarine Fringe Pine Forests |
merged into the Maritime Swamp Forests group |
| Estuarine Fringe Swamp Forests | merged into the Tidal Baldcypress Forests and Woodlands group |
| (not represented) | a new HIGH-ENERGY TIDAL SHORES group was added to represent vegetation previously included in the Tidal Freshwater Marshes group |