Remnant Bottomland Forests near the Terminus of the Mississippi River in Southeastern Louisiana

The woody communities of seven of the most intact bottomland hardwood forests of southeastern Louisiana are described. The seven forests are on old levee ridges associated with past distributaries of the Mississippi River. The communities were divided by diameter size class into overstory (~10.0 cm dbh) and understory (3.0 cm 2 10.0 cm dbh). The overstory (27 species) and understory (24 species) shared 18 species out of a total of 33. The understory stratum in these forests was not as uniform as the overstory across the forests in both dominants and subdominants. The forests were divided into two groups based upon size and abundance of two dominant overstory trees, live oak (Quercus virginiana) and sugarberry (Celtis laeuiguta). Other important overstory taxa were water oak (Quercus nigra), red maple (Acer rubrum), sweetgum (Liquidambar styruciflua), and elm (Ulmus spp.). The average total overstory density for the forests was 358.5 stems/ha and the average total overstory basal area was 30.5 mYha. The effect of microtopography, with its impact on hydroperiod, along and across the levee ridges was likely the principal variable impacting species dominance and diversity across the forests. These forests are under severe threat and conservation of those still remaining is a priority.