| Table 1: Status of vegetative types in St. Tammany Parish |
| Vegetative Type | Abundance/Status | Trend | Causes | Notes |
| Aquatic |
| Submersed Estuarine Grassbeds | Very rare | May be slowly increasing | Improving water quality benefitting grassbeds | Restricted to shallow brackish water near north shore of Lake Pontchartrain |
| Fresh Floating/Submersed Vegetation | Common | Stable | | |
| Wetlands |
| Fresh Marsh | Rare | Stable/very slowly declining | Saltwater intrusion | |
| Intermediate Marsh | Common | Stable/very slowly declining | | Restricted to marsh zone on north shore of Lake Pontchartrain and mouth of Pearl River |
| Brackish Marsh | Uncommon | Stable/very slowly declining | | |
| Hillside Seepage Bog | Exceedingly rare | Declining | Fire suppression diminishing habitat | |
| Bald Cypress/Bald Cypress-Tupelo Swamp | Common (second growth) | Slowly declining | | Occupies floodplains of large, permanent streams |
| Pond Cypress/Blackgum Swamp | Rare | Slowly declining | | Old growth very rare |
| Bottomland Hardwood Forest | Common (second growth) | Slowly declining | | Old growth very rare |
| Small Stream Forest | Common (second growth) | Declining | Loss due to clearing and commercial forestry | Old growth very rare |
| Bayhead Swamp | Common (poor quality) | Declining | Loss due to drainage and habitat conversion | High-quality examples rare. A major secondary forest type in southeastern St. Tammany |
| Slash Pine-Pond Cypress/Hardwood Forest | Critically imperiled | Declining | Loss due to fire suppression and habitat conversion | Once major secondary forest type in southeastern St. Tammany. Less than 2,000 acres remain in natural state. |
| Slash Pine/Wiregrass | Rare | Probably declining | | Restricted to narrow marsh fringe zone in flatwoods region. Large areas recently incorporated in Big Branch National Wildlife Refuge. |
| Gum Pond | Uncommon | Probably declining | | Old growth very rare |
| Shrub Swamp | Uncommon | Slowly declining | | |
| Forested Seep | Rare | Declining | Loss due to habitat conversion | Restricted to sandy fire protected of uplands of northern St. Tammany. High-quality examples rare. |
| Longleaf Pine Flatwood Savannah | Rare | Declining | Loss due to fire suppression and habitat conversion | Once major secondary forest type in southeastern St. Tammany. Less than 3,000 acres remain in natural condition. |
| Uplands |
| Hardwood Slope Forest | Very Rare | Declining | | Restricted to hilly uplands of northeastern St. Tammany. High-quality examples rare. |
| Mixed Hardwood-Loblolly Forest | Uncommon (second growth) | Declining | | Old growth very rare. Once a major secondary forest type in parish. Still present along intermittent stream bottoms and fire-protected flatwoods. |
| Shortleaf Pine/Oak-Hickory Forest | Critically imperiled | Declining | Loss due to fire suppression and habitat conversion | Once fairly common on upper steep slopes, finger ridges and peninsulas in longleaf pine uplands. Less than 1,000 acres remain in natural condition. |
| Longleaf Pine Flatwoods | Critically imperiled | Rapidly Declining | Loss due to fire suppression and habitat conversion | Once major secondary forest type of pine flatwoods in southeastern St. Tammany. Less than 3,000 acres remain in natural condition. |
| Upland Longleaf Pine Forest | Critically imperiled | Rapidly Declining | Loss due to fire suppression and habitat conversion | Once a dominant forest type of hilly uplands of parish. More than 100,000 acres 100 years ago. Less than 5,000 acres remain. No old growth remains. |
U. S. Department of the Interior |