A Gradient Analysis of Understory Vegetation in a Sugarberry-Elm Floodplain Forest on the Brazos River

Perry J. Grissom, David B. Wester


Relationships between understory vegetation pattern, topography, flooding, and soil properties were studied in a bottomland hardwood forest on the lower Brazos River floodplain. Elevation varied 30 to 70 cm along 220-m transects in three study sites. We infer that a microtopographically-induced soil aeration gradient influenced understory vegetation pattern. Swales were flooded from autumn through spring and supported species-poor vegetation dominated by Panicum gymnocarpon. Unflooded areas supported more diverse vegetation varying in composition along an elevation gradient: Carex cherokeensis characterized lower elevations, with dominance graduatlly shifting to Oplismenus hirtellus on slightly elevated ridges. Vegetation pattern was strongly related to relative elevation and soil water content as well as to abundance of clayey horizons in the soil profile, and soil copper, iron, phosphorus, potassium, and salinity.


floodplain; understory; vegetation pattern; flooding; Brazos River

Full Text:



  • There are currently no refbacks.