INLAND SAND DUNE MYCORRHIZAE - EFFECTS OF SOIL DEPTH, MOISTURE, AND PH ON COLONIZATION OF ORYZOPSIS HYMENOIDES

The occurrence of vesicular arbuscular mycorrhizae was reconfirmed in Oryzopsis hymenoides, a major graminoid species on western sand dunes. A bioassay was used to determine the ability of soil from O. hymenoid es stands to support formation of vesicular arbuscular mycorrhizae. Re gression analyses of the bioassay results were used to predict the rel ationship between mycorrhiza formation and differences in surrounding vegetation and differences in initial soil depth, soil water content, and soil pH. There was a strong positive correlation between mycorrhiz a formation and the amount of above ground plant cover. There was a st rong negative correlation between mycorrhiza formation and increases i n initial soil depth, moisture, and pH.