Abstract:
Growth including total height, diameter at root collar, biomass, carbon accumulation and carbon dioxide absorbtion were studied among the 4 mangrove species with 7 years old namely Rhizophora apiculata, Avicennia marina, Bruguiera cylindrical and Ceriops tagal planting on abandoned shrimp farm at Kanhom District, Nakhon Si Thammarat Province. Three hundred plants of each species were sampled for the growth measurement. Results showed that the highest average total height was found in R. apiculata (3.96 m) followed by A. marina (3.27m), C.tagal (2.43 m) and B. cylindrical (2.39 m), respectively. The highest average of diameter at root collar was found in R. apiculata (8.12 cm) followed by A. marina (7.50 cm), B. cylindrical (6.90 cm) and C. tagal (6.25 cm), respectively. The highest total biomass was found in R. apiculata (128.5 tonnes/ha) followed by A. marina (34.89 tonnes/ha) and C. tagal (32.81 tonnes/ha) and while B. cylindrical (27.44 tonnes/ha) had lowest total biomass. The carbon dioxide abosrbtion was measured by LCA 3 with Parkinson Leaf Chamber in November (wet season) and March (dry season). The carbon accumulation was measured by CHNO analyzer. The highest carbon dioxide absorbtion was found in A. marina with the value of 6.49 µmol m⁻²s⁻¹ in wet season , 4.42 µmol m⁻²s⁻¹ in dry season. The highest carbon accumulation was found in R.apiculata (49.88 tonnes carbon/ha) followed by C. tagal (15.38 tonnes carbon/ha) A. marina (14.18 tonnes carbon/ha) and B. cylindrical (14.00 tonnes carbon/ha), Respectively. This investigation will be considered in selecting suitable mangrove species to rehabilitate on abandoned shrimp farm successfully.