2015 Volume 6 Issue 1 Pages 40-45
This research is aimed to documenting the diversity of plant species that are found on slightly saline soils in the Chi river basin of Northeast Thailand. Both in the dry and the rainy seasons of 2013, plant surveys were conducted at selected sites in three provinces (Chaiyaphum, Khon Kaen, and Kalasin) by using a quadrat sampling technique. Soils under the dominant plant species were collected for physical and chemical analyses. From the study, a total of 155 plant species belonging to the 72 families were recorded. Five of those were classified as halophytes, and included Azima sarmentosa, Maytenus diversifolia, Synostema bacciformis, Pluchea indica and Gisekia pharnaceoides. The dominant species in the selected sites of three provinces were Cynodon dactylon, Heliotropium indicum, Melochia corchorifolia, Ageratum conyzoides, Coldenia procumben, Glinus oppositifolius and Panicum repens, respectively. In the dry season, the average soil electrical conductivity under the dominant plant species at Chaiyaphum, Khon Kaen and Kalasin provinces were 2.52, 0.7 and 0.54 dS/m, respectively. In the rainy season, the averaged soil electrical conductivity under the dominant plant species were decreased to 0.61, 0.37 and 0.14 dS/m in Chaiyaphum, Khon Kaen and Kalasin provinces, respectively. In all studied areas during in both seasons, the amounts of exchangeable sodium were in the same direction as the values of electrical conductivity. Soil pH values at all studied areas in both seasons were in an acidic condition. However, the pH values were lower in the dry season than in the rainy season. Soil moisture under the dominant plant species was higher in the rainy season than that in the dry season.
