COMPARISON OF CEDAR GLADES AND ASSOCIATED WOODLANDS OF THE SOUTHERN EDWARDS-PLATEAU

Phytosociological, physical and chemical characteristics were examined in seven cedar glade communities and their associated woodlands in th e southern part of the Edwards Plateau of central Texas. Of 15 woody a nd five succulent species found in the two communities, two species we re restricted to the cedar glades and eight to the woodlands. Total me an density for woody and succulent plants in the cedar glades was 1,14 6 plants/ha and for the woodlands was 10,719 plants/ha. Total mean bas al area for woody and succulent plants in the cedar glades was 2.59 m( 2)/ha and 57.58 m(2)/ha for the woodlands. Mean grass cover for the ce dar glades was 11% and 3% for the woodlands. Mean herbaceous cover for the cedar glades was 2%, but for the woodlands it was less than 1%. C edar glades were found to be significantly higher in mean light levels , pH, sulfur and sodium while woodlands were significantly higher in m ean slope angle, soil depth, salinity, percent organic content and mag nesium. Shallow soil combined with low water availability during the s ummer appears to prevent the establishment of woody species in the ced ar glades while low light levels in the woodlands probably limits gras ses and herbaceous growth to the open cedar glade habitat.