Jetsada Wongprom
Faculty of Forestry, Kasetsart University 50 Ngamwongwan Road. Ladyao Chatuchak, Bangkok, 10900 Thailand

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GROWTH PERFORMANCE OF DIPTEROCARP SPECIES PLANTED ON ABANDONED MINING AREA IN SOUTHERN THAILAND Jetsada Wongprom
BIOTROPIA - The Southeast Asian Journal of Tropical Biology Vol. 27 No. 2 (2020)
Publisher : SEAMEO BIOTROP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11598/btb.2020.27.2.1173

Abstract

Dominant Dipterocarp trees hold a significant importance in the ecology and economics of the declining tropical forests of Asia. Of equal importance is the restoration of these Dipterocarp forest using the technique of matching species with silvicultural practices. The study aimed to investigate the effect of the Acacia mangium nurse trees on the survival and growth of six Dipterocarp species planted on abandoned mining areas in the Phangnga Forestry Research Station, Thailand, namely; Dipterocarpus alatus Roxb., Dipterocarpus gracilis Blume, Hopea odorata Roxb., Shorea gratissima (Wall. ex Kurz) Dyer, Shorea roxburghii G. Don, and Parashorea stellata Kurz. The approximately 1.5-year-old Dipterocarp seedlings were planted at a 6-year-old A. mangium plantation cover and at open plots. The survival rate, diameter at root collar (D0), total height (H) and the relative growth rate (RGR) of D0 and H of the seedlings were compared. Soil samples at the open and the A. mangium plots were collected and its physical and chemical properties were analyzed. The results indicated that the survival rates of the Dipterocarps planted at the A. mangium plot were higher than those at the open plots. The survival rates (75-100%) of the 1 to 3-year-old D. alatus, H. odorata, S. gratissima, S. roxburghii, and P. stellata were relatively high at the A. mangium plot, but not for D. gracilis. The D0 of S. roxburghii, D. alatus, H. odorata, and P. stellata were higher at the A. mangium plot. However, the D0 and H of S. roxburghii, D. alatus, and H. odorata at the open plot were high and similar to that of the A. mangium plot. RGRD0 and RGRH of S. roxburghii, D. alatus, and H. odorata were high both at the A. mangium and the open plots. Generally, the Dipterocarp seedlings were growing better under the A. mangium nurse trees, thus suggesting the possibility of their improved survival and growth in mined out areas. Moreover, the findings also suggest that S. roxburghii, D. alatus, and H. odorata can be planted at open areas with poor soil conditions and extreme environments. Lastly, thinning interventions are also needed to improve the growth of Dipterocarp trees.
LITTERFALL, LITTER DECOMPOSITION AND NUTRIENT RETURN OF REHABILITATED MINING AREAS AND NATURAL FOREST IN PHANGNGA FORESTRY RESEARCH STATION, SOUTHERN THAILAND Jetsada Wongprom; Roongreang Poolsiri; Sapit Diloksumpun; Chatchai Ngernsaengsaruay; Samita Tansakul; Wasan Chandaeng
BIOTROPIA - The Southeast Asian Journal of Tropical Biology Vol. 29 No. 1 (2022): BIOTROPIA Vol. 29 No. 1 April 2022
Publisher : SEAMEO BIOTROP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11598/btb.2022.29.1.1627

Abstract

Litterfall and litter decomposition play important roles in the maintenance of nutrient cycling and rehabilitation of degraded lands. Litterfall, litter decomposition and nutrient return were investigated in a 27-year-old Acacia mangium plantation on sandy and clay sites, and in a mixed plantation at the Phangnga Forestry Research Station, Phangnga Province, Thailand. Additionally, secondary and primary forests were investigated and compared with the values obtained from the Acacia mangium and the mixed plantations. The results indicated that litter production in A. mangium plantation on sandy and clay sites, and in mixed plantations (15.47, 11.68 and 7.89 t/ha/yr, respectively) was higher than that in the secondary and primary forests (6.34 and 6.92 t/ha/yr, respectively). The rate of litter decomposition was the greatest in the secondary forest (3.01/yr) and the lowest occurred in the primary forest (1.15/yr). The decomposition rate of the mixed leaf litter between native trees and A. mangium in plantations was higher than that of only A mangium leaf, except in the mixed plantations. A high initial nitrogen concentration in A. mangium could accelerate litter decomposition and improve litter quality in the mixed litter. In addition, the nutrient return in plantations was higher than that in the secondary and primary forests, especially for N. Increased litter production, high decomposition rate and nutrient return from A. mangium plantation had important roles in nutrient cycling, suggesting that a mixed plantation consisting of A. mangium and native trees should be considered for the reclamation of mining land.   Keywords: litter decomposition, litterfall, mining rehabilitation, nutrient return, tropical forest
EFFECT OF THINNING ON GROWTH AND WOOD PRODUCTION OF NATURALLY REGENERATED 8-YEAR-OLD ACACIA MANGIUM WILLD. PLANTATION ON ABANDONED MINING AREA, SOUTHERN THAILAND Jetsada Wongprom; Somporn Maelim; Wasan Chandaeng; Sakhan Teejuntuk; Monthathip Sommeechai; Decha Duangnamon
BIOTROPIA Vol. 30 No. 3 (2023): BIOTROPIA Vol. 30 No. 3 December 2023
Publisher : SEAMEO BIOTROP

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11598/btb.2023.30.3.1919

Abstract

Thinning is an important practice for promoting growth and maintaining forest plantation for wood production from the remaining trees. In this study, thinning was carried out in a naturally regenerated 8-year-old Acacia mangium plot in the Phangnga Forestry Research Station. Three thinning schemes, with 175 (T1), 300 (T2) and 600 (T3) remaining trees/ha, were compared with the control (no thinning) of 831 trees/ha. The diameter at breast height (DBH) and height (H) of the trees were measured. The differences in growth, current annual increment (CAI), aboveground biomass, and stem volume (V) were analyzed. We observed that the thinning of A. mangium increased the growth rate, with the DBH being clearly affected by thinning. CAIDBH increased significantly, with the DBH class of thinned A. mangium plots also improving after thinning. The stem volume and aboveground biomass of T3 plot was similar to the control plot after thinning. In addition, the number of large saw logs was the highest in T3 plot. The large saw logs can be used for multi-utilization and have a high value. These results suggest that thinning can promote stem growth, and increase the proportion of large saw logs in naturally regenerated A. mangium stands.