ECOPHYSIOLOGY AND GROWTH PATTERNS OF CRYPTOPCORYNE STRIOLATA ENGLER AT SUNGAI STUUM TOMAN, BAU, SARAWAK

The study on the ecophysiology, survival and growth patterns of Cryptopcoryne striolata Engler (Araceae) was conducted 4 km along Sungai Stuum Toman, Bau, Sarawak. The occurrence of C. striolata is considered abundant in this river. The total number of patches, average area of patches, plant density and total biomass tended to increase toward the middle part of the river and then decrease further downstream. There was obvious variation in the growth pattern of C. striolata in different water depths and positions in the river. C. striolata plants tended to grow well in deep water as shown by its total number of leaves, leaf length, dry weight, leaf area, leaf area ratio and specific leaf area. Sungai Stuum Toman was mainly covered by secondary forest (belukar). The result revealed that 36 and 38 species of trees above 5 cm DBH (diameter breast height) with the estimated above ground biomass of 85.26 ton/ha and 78.39 ton/ha from the presence and absence of C. striolata, respectively. The highest concentration of elements was Potassium (K) (0.992 mg/l) and then followed by Iron (Fe) (0.783 mg/l), Calcium (Ca) (0.327 mg/l), Magnesium (Mg) (0.154 mg/l), Zinc (Zn) (0.01 mg/l) and Copper (Cu) (0.007 mg/l). The population abundance of C. striolata in the Sungai Stuum Toman is probably due to sufficient vegetative coverage as well as favorable water quality to sustain its population.