Carbon stock assessment using remote sensing and forest inventory data in Savannakhet, Lao PDR | |
| Author | Phutchard Vicharnakorn |
| Call Number | AIT Diss. no.NR-16-01 |
| Subject(s) | Forest Inventory and Analysis Program (U.S.) Forests and forestry--Remote sensing--Laos--Savannakhet |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Natural Resources Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. NR-16-01 |
| Abstract | In today’s climate change mitigation concepts, forests play an important role as carbon sink, while deforestation and forest degradation add to greenhouse gases emissions. This study aimed to develop a method for estimating forest carbon stock and trends. The biggest carbon pools in tropical forest ecosystems are in the biomass of living trees, soil organic matter and the dead mass of litter, woody debris and understory vegetation. The estimation of carbon stocks and fluxes in tropical forests can be computed from above-ground living biomass (AGB). A longstanding problem of the Lao People’s Democratic Republic (PDR) has been a significant loss of forests of 47 percent between 1950 to 1992 mainly due to population increase, agriculture and timber exports (ICEM, 2003). Savannakhet Province, located in central Lao and linked to Thailand and Vietnam via road No. 9, has seen massive deforestation. To determine the carbon released by deforestation, the total AGB and carbon stocks of different land-cover types were measured. This study assessed AGB and carbon stocks (t/ha) of vegetation and soil using standard forest inventory sampling techniques and allometric equations. A total of 81 plots, each measuring 1600 m2, were established representing various land cover types, such as evergreen forest (DEF), mixed deciduous forest (MDF), dry dipterocarp forest (DDF), disturbed forest (DF), and paddy fields (PFi). In each plot, the diameter at breast height (DBH) and height (H) of the overstory trees were measured during the field observation in 2009 as reference year. Soil samples were collected at depths of 0–30 cm. Soil carbon was measured using soil depth, soil bulk density, and carbon content. Remote sensing data (Landsat Thematic Mapper) were classified to produce land cover maps and develop a biomass estimation model by investigating the relation between field observed data, other ancillary data and remote sensing data. Finally, carbon stocks were estimated for 1994 to 2010 used the developed models. The classification analysis indicated that MDF accounted for the largest area coverage, followed by DDF, PFi, DF, and DEF. The results of the total carbon stock assessments from the ground data showed the highest value for the MDF site, followed by DEF, DDF, DF, and PFi sites. A comparison of regression coefficients among the different models generated showed that a regression model based on a single TM band(TM7 or TM4) had a sufficiently strong relation with field observed biomass data and hence was satisfactory in developing biomass estimation models for DEF and DDF land cover types but not for MDF, DF, and PFi where a combination of variables (e.g., VIs and elevation) could return satisfactory results. The highest average carbon stock was found for the year 1994. The total above-ground carbon stocks for each land cover class in 1994, 2005, 2007 and 2010 were found to have dramatically decreased from 1994 to 2010, especially from 2007 to 2010. MDF had the biggest carbon stock, followed by DEF, DDF, DF, and PF land cover types. The findings also showed that non-forest areas had dramatically increased from 1994 to 2010. Consequently, to increase carbon stock in the Savannakhet area and reduce emissions from deforestation and forest degradation, DEF and MDF should be protected and the role of conservation, sustainable forest management enhancing forest carbon stocks (REDD+) in Lao PDR promoted. |
| Year | 2016 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. NR-16-01 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Development and Sustainability (DDS) |
| Academic Program/FoS | Natural Resources Management (NRM) |
| Chairperson(s) | Shrestha, Rajendra Prasad; |
| Examination Committee(s) | Salam, P. Abdul ;Nagai, Masahiko ;Somboon Kiratiprayoon; |
| Scholarship Donor(s) | Royal Thai Government ;Asian Institute of Technology Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2015 |