Species and Physiographic Relationships

Forest vegetation types relate directly to physiographic conditions. Sweetgum and water oak trees capture many first bottoms. White and red oaks prevail on first bottom ridges and on terraces, while the hackberry-elm-ash type occurs on low ridges, flats, and sloughs in the first bottoms. Overcup oak and bitter pecan often seed-in together on poorly drained flats typically characterized by tightly compacted clay soils.

On new land formed by sand deposits at a river's edge, called fronts, the pioneer eastern cottonwood makes phenomenal growth. Sometimes this prolific seeder captures old fields recently abandoned from agriculture where the land is a well-drained ridge in a first bottom. Black willow, another pioneer species, also seeds-in to form dense stands in fronts. Cottonwood and willow together, fairly shade-tolerant trees, occasionally take over shallow swamps and deep sloughs in the first bottoms.

Tupelo gum trees grow among the baldcypress stems in the lowest, poorly drained flats. This combination, widely distributed throughout the region occurs both in small blocks and in extensive areas in the lower reaches of the estuaries of major streams.30

0 0

Post a comment