| Summary: | 碩士 === 國立中興大學 === 水土保持學系所 === 98 === The increase of greenhouse gas emission has led to serious effects of global warming. Inter-countries have promoted the mitigation strategies and established intergovernmental panels to formulate international covenant. In addition to the development of green energies would enhance utilization efficiency of energies and decrease carbon source, reduction of atmospheric carbon content by means of carbon sink has been developed and researched gradually since the benefits of low cost, high efficiency, and simple operation. Forest carbon sink was regarded particularly. In this study, changes of carbon stocks at different period in Taiwan and effects of different land use on the carbon stocks were investigated. Then greenery deterioration index (GDI) derived from satellite image was used to estimate carbon stocks indirectly. Moreover, forest ecosystem plays an important role in carbon cycle. In order to understand changes of carbon flux in forest ecosystem, Forest-DNDC model was selected for simulation.
Six vegetation types were extracted by using the data derived from Land Use Investigation of Taiwan (1995 and 2008) to calculate the carbon stocks of each vegetation type following the method of Intergovernmental Panel on Climate Change (IPCC). Results show that the increase amount of carbon stocks is 9,355,116 tons for the phase of 1995~2008, and the amount of average carbon stocks for the main land-use categories in Taiwan are forestry, aboriginal reserve, slope land, and urban planning area in order. It shows that land-use pattern related to carbon stocks significantly. Furthermore, correlation analysis indicates the GDI derived from SPOT satellite images of 12 rural villages which were selected as the study areas having a highly negative correlation with carbon stocks, hence can be effectively used as an index to estimate the amount of carbon stocks.
Data of Cirques and Dark forests at Xue Mountain were collected and applied to simulate the model of Forest-DNDC. Results depict that litter had significant effects on soil organic carbon (SOC). Both SOC content and net ecosystem exchange (NEE) of carbon show a trend of gentle decline and have a flat gradient gradually for the simulation of 2008~2017. Comparing the scenarios of increasing temperature (0.01℃/yr) and current status, the difference of NEE is larger than that of SOC, and the net increasing amount of NEE is from 0.02% to 0.98% annually. Temperature and pH are the main factors, which significantly affect carbon flux. Sensitivity analysis shows that the amount of carbon flux can be adjusted sensitively by temperature in the simulation.
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