Determination of forest trees stress in 1 ha plot dipterocarp forest at Gunung Basor Forest Reserve

The information on forest trees at the east coast of Malaysia particularly in Kelantan is scanty. No prior studies have been carried out to determine vegetation stress in Kelantan. This study was conducted to determine the vegetation stress in 1 ha plot of dipterocarp forest at Gunung Basor Forest Reserve. Vegetation stress may be defined as any factor that reduces productivity below the optimum value. For the vegetation stress, the measured parameters were ambient temperature, soil pH and soil moisture content. The temperature of 137 individual trees found in 1 ha plot was using infrared thermometer. The highest temperature was 27°C which at the number of tree 67 with dbh value was 7.04 cm. The temperature for these trees was higher than others because of the location was exposed to the sun compared to others trees. The lowest temperature was 21.1 °C with dbh value 10.19 cm. The pH value at Gunung Basor was within the range of 6.0 to 7 but mostly 6.5. This finding indicated that the soil pH in Gunung Basor still in optimum range level of pH value. Eighteen sample of soil were taken randomly from study 1 ha plot dipterocarp to measure the soil moisture contents. The highest soil moisture content was 68.41% with tree temperature was 22°C while the lowest soil moisture content was 10.63 % which tree temperature was 23.7°C.This study is vital in providing data about plant stress that was affected by ambient temperature, soil pH and soil moisture content of trees. In addition, this study also acts as a guideline for forestry department and in agriculture sector when dealing with drought.