Bottomland Forests of North‐Central Oklahoma

The vegetation and selected edaphic factors of 47 stands of floodplain forest communities were examined in 10 north—central Oklahoma counties. Soil factors analyzed were pH; total nitrogen; total phosphorus; organic carbon; and percentage of sand, silt, and clay at the 0— to 6—inch and 18— to 24—inch levels. Normal precipitation in the study area varied from 28.0 to 37.5 inches. Ten types of communities were present, with Ulmus americana a dominant in six types and a dominant in 38 of the 47 stands sampled. Celtis occidentalis was dominant in only six stands. Other species which were dominant in at least one stand were Sapindus drummondii, Carya illinoensis, Fraxinus pennsylvanica, Celtis laevigata, and Juglans nigra. Ulmus americana occurred as a dominant throughout the entire area, whereas Sapindus drummondii occurred as a dominant in only the more xeric western countries and all other species occurred as dominants only in the central or eastern countries. The number of tree species increased markedly (11 to 23) and density increased slightly from west to east. No such trend was noted in basal area. The pH of the soil varied from above 8.0 in the west to 6.8 in the east. No consistent trends from west to east were evident in other soil factors analyzed. The best overall correlation appeared to occur between basal area and a combination of total nitrogen at the 18— to 24—inch level and normal precipitation. There were no apparent correlations between the type of plant community or the distribution of individual species and the soil factors analyzed.