Carbon stock in biomass and soil of private mangrove plantations (Rhizophora apiculata Bl.) in Yisan Sub-District, Amphawa District, Samut Songkram Province, Thailand | |
| Author | Kanokwan Homcha-aim |
| Call Number | AIT Thesis no.NR-10-08 |
| Subject(s) | Mangrove forests--Thailand--Samut Songkram Forest biomass--Thailand--Samut Songkram Soils--Carbon content--Thailand--Samut Songkram |
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Natural Resources Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. NR-10-08 |
| Abstract | The study of carbon stock in biomass and soil of private mangrove plantations (Rhizophora apiculataBl.) was conducted in Yisan Sub-district, Amphawa District, Samut Songkram Province of Thailand, where the wood from private plantations was used for charcoal production until now. The result from the interviews of 8 plantation agriculturalists for the study of plantation management can be concluded that the main purposes of the plantation management in Yisan were for charcoal making (98%) and for pole (2%). The silvicultural system applied for R. apiculatain Yisan was a clear-felling system with varied cutting rotation from 8-to-15 years, depending on tree size. Site preparation required only some small canal digging, scattered within and/or at the edge of the planting areas, to provide sea water flooding. Seedlings were collected from the existing plantations. Initial planting was done with the density at 25,000 to 30,000 propagules/ha with a spacing of approximately 0.5 x 0.5 to 0.6 x 0.6 m. Vacancy filling and weeding were applied in the 2ndto 4thyear. Thinning and pruning were never carried out due to natural thinning and pruning and high labor cost. Harvesting was performed throughout the year. The final product for charcoal making was de-barked billet with 1.30 to 1.42 m length. The data from tree measurement of each of the 6 sample points of the15 different age classes was analyzed using Microsoft Excel and SPSS version 16, and showed that the survival rate of the plantations decreased with age. The initial planting number of propagules at 25,000 propagules/ha decreased to 21,300 propagules/ha in the first year or 95.2%. The survival rate was less than 50% in the plantations beyond 11 years old and lowest in the 15year old plantations, at 40.8% of the initial planting number. GBH and height of the plantations increased with age. The average GBH of3-to-15 year old plantations and the height of 1-to-5 year old plantations varied from 8.47±1.30 to 22.49±2.23cm, and 0.41±0.05 to12.23±2.17m, respectively. The average CAI of GBH and height of the plantation were 1.91±0.18cm/yrand 0.80±0.10m/yr, respectively. Biomass production of the plantation was estimated by using the allometry equation. The results found that biomass production of every part of the trees (trunk, stilt, leaf, and below-ground) increased with age. The highest biomass production of trunk, stilt, leaf and below-ground was found in15 year old plantations at 187.09±46.38, 31.74±7.86, 16.73±2.27, and 22.07±3.31tonnes/ha, respectively and resulted in the highesttotal biomass production at 257.63±59.81tonnes/ha. Partitioning ofbiomass production of the plantations beyond 3years old in trunk and stiltincreasedwith increasing age, conversely, in leaf and below-grounddecreased with increasing age. Six pictures from each age class were analyzed for the percentage of crown cover by using Adobe Photoshop program. The results showed that tree stands almostcompletelycovered the plantation area around the age of 4yearsold and beyond. The highest percentage of crown cover was found in 7 year old plantations at 93.06±1.03%. Two litter traps were set up in each age class for the study of litter fall production. The results found that thehighest litter fall production was found in 5yearold plantations at 0.48±0.01tonnes/ha/month.Carbon stock in biomassof the 15 age classplantations was estimated by dividing biomass production by 0.47 conversion factor. The result found that carbon stock in biomass of all the tree parts (trunk, stilt, leaf, and below-ground) increased with age.Total carbon store in biomass of 1-to-15year-old R. apiculataplantations varied between 3.89±1.36to iv121.09±28.11tonnes/ha.Carbon store in trunk, stilt, leaf, and below-ground biomass was observed as the highest in 15 year old plantations at 87.93±21.80, 14.92±3.69, 7.86±1.07, and 10.37±1.55tonnes/ha, respectively and resulted in the highest total carbon store in biomass at 121.09±28.11tonnes/ha. Soil carbon stock of 1-to-15yearold plantations varied between 58.58 to 96.65 tonnes/ha.The highest was reported in 14yearold plantations while the lowest was in 3yearold plantations. Carbon stock in the top soil (0 to 15 cm) was higher than in the bottom soil (15-to-30 cm) in every age class.Total carbon stockof 1-to-15yearoldplantations varied between 64.68 to 211.46tonnes/ha, the highest being found in 14yearold plantations and the lowest in 3-year-old plantations. The total carbon sequestration was derived mainly from carbon in soil in younger age plantations (1-to-10 years old) whereas in older age (beyond 10 years old), carbonsequestration was derived from total carbon store in biomass. |
| Year | 2010 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. NR-10-08 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Development and Sustainability (DDS) |
| Academic Program/FoS | Natural Resources Management (NRM) |
| Chairperson(s) | Cochard, Roland |
| Examination Committee(s) | Shrestha, Rajendra Prasad;Kumar,Sivanappan |
| Scholarship Donor(s) | HM Queen Scholarship |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2010 |