Success of mangrove planting under different environmental conditions

Success of mangrove planting under different environmental conditions
ความสำเร็จของการปลูกป่าชายเลนในสภาพพื้นที่ต่างกัน

Noparat Bamroongrugsa, Assoc. Prof., D. of Biology, F. of Sci., PSU.
E-mail : bnoparat@ratree.psu.ac.th

Grant : JICA
Presented : The 11th National Seminar on Mangrove Ecology, 9-11 July 2000, Trang Plaza Hotel, Muang, Trang, Thailand
Key words : mangrove planting, mangrove restoration, mangrove rehabilitation

The establishment or restoration of mangroves needs proper management techniques particularly when the planting operation is carried out in the areas unsuitable for natural mangrove regenera-tion. In general, the suitable habitat for mangroves is in the tidal range of muddy coastlines or in the bay with a shelter for strong wind and wave. Both wind and wave, however may cause undermining of the mangrove roots as well as the deposition of sediment. Reports on mangrove planting both from Thailand and other countries show varying rates of success (0-100 percent). In addition to wind and wave actions, success rates in many locations are mainly attributed to habitat selection, plant mate- rials, planting techniques, seasons, mangrove species, sea debris, pests, tidal action, water quality, water salinity, soil salinity as well as the disturbance caused by fishing boats. Experiment conducted in February 2000 at Songkhla Lake of Kuanniang District which was supported by Japan International Cooperation Agency (JICA) and Thailand Union for Mangrove Rehabilitation (TUMREC) demonstrated that the bamboo fence (3.5 m. tall, 520 m. long) could be used as a shelter to protect wind and wave actions. In addition, the planting area of 70 rai (11.2 ha) in a small bay of the lake is directly affected by seasonal monsoon which normally does not facilitate natural mangrove establishment. When propagules, bagged seedlings of Rhizophora mucronata (spacing 2x2 m.) and root-ball seed-lings (2 year old) of Sonneratia caseolaris (spacing 3x3 m.) were used and each plant was supported by a stick, it was found that at 4 months after planting the survival rate was most successful (excess 85 percent). In contrast, root-ball seedlings of R. mucronata yielded total loss of plants and then replaced by the seedlings of S. caseolaris. Also it is remarkable that at about 10 days after plants most leaves of S. caseolaris wilted but soon after that new leaves would emerge.

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