Clumps and Culms Establishment of Gigantochloa albociliata and Cephalostachyum pergracile after Gregarious Flowering in the Mixed Deciduous Forest at Mae Klong Watershed Research Station, Kanchanaburi Province

Abstract

All studies were conducted at Mae Klong Watershed Research Station, Kanchanaburi province during June 2005 to October 2006. The 20 sample plots of 1 m x 1 m were used for both species in each different site, open gap and under crown canopy. All clumps were dug from the sample plots and washed to measure the size according to their ages and species for their growth analyses. Light conditions were taken by hemispherical photos at the same sites both in the rainy and dry. The results showed that growth of bamboos was highly correlated to their aged clumps. Their growth was significantly different between the sites for both Gigantochloa albociliata and Cephalostachyum pergracile (Z = -20.065 and -17.470, p < 0.001, respectively). Light intensity played an important role on clump establishment. The standard overcast sky distribution (SOC %) was higher in the dry season than in the rainy season of both areas, open gap (16.26 and 7.75%, respectively) and under crown canopy (4.21 and 2.18%, respectively). To estimate the period on clump establishment, the growth rate equations were analyzed and applied. The results showed that both G. albociliata and C. pergracile rapidly succeeded to establish in the short time period, especially under gap condition, 27.17 ± 0. 29 and 12.30 ± 0.87 years, respectively and much longer time under the crown canopy condition, 66.74 ±0.70 and 28.78 ± 2.05 years, respectively. To promote the bamboo plantations, thus, light intensity in the planting sites should be considered as the principle components. In addition, sources of planting matemals are also important in rough approximation of flowering periods.

Key words: Gigantochloa albociliata, Cephalostachyum pergracile, mixed deciduous forest, forest dynamics, bamboo flowering