執行成果摘要
After tending practice, litterfall of different Hinoki forests varied greatly in Chi-Lan Shan area, including seasonal, annual, and among stand variations. The minimum monthly amount of litterfall is only 0.9% of the maximal one. The total amount of this year will be estimated higher than it of last year. It may range from 2.28~3.11 ton/ha/yr at different stands in 2011. To improve the carbon sequestration in Hinoki forests, long term monitoring is necessary to find out the most appropriate management. It is estimated the litter layer will release 1.37~1.88 ton/ha/yr CO2 at Hinoki forests in Chi-Lan Shan area.
Several native species were replanted at unsuccessful forestation at Hualian. Eight months after supplement planting, survivorship increased from 57.46% in 2011 to 72.96% in September 2012. Fertilization significantly improved the survivorship of Paulownia to 99%. Acacia auriculiformis grows best at under-stocking and successfully forestation areas. At Guanmau successfully forestation area, Araucaria cunninghamii has the highest carbon sequestration of 123.89±22.52ton/ha, followed by Swietenia macrophylla of 115.97±27.79ton/ha. Machilus zuihensis has the lowest of 25.76±8.39ton/ha. The average CO2 sequestration at this near 418 ton CO2e/ha. As the canopy is near closed, varied thinning operations will be carried out.
Agroforestry combines sustainability and farmers’ livelihood. Less restriction in policy and more research are necessary. The survey in this year showed the 17-year-old Calocedrus formosana interplanting in tea garden are growing fast. The CO2 sequestration increased from 40 tons in last year to 65 tons CO2e/ha this year. Five study sites were established in north, east and center Taiwan, respectively. Calocedrus formosan, Phellodendron amurense var. wilsonii, Prunus taiwaniana, Cinnamomum kanehirae, Cinnamomum osmophloeum were interplanted in farmland. Tending practice will significantly affect the survivorship of seedlings. One more farm was transfer to agroforestry at Kalala in Hualian with interplanting Ficus pumila L. var. awkeotsang and betel palms. Crop productivity evaluation, such as betel nuts at Yuchi, is recorded from this year. However, as most seedlings are still small, long-term observation is required.
In terms of area and precipitation of agroforestry sites, soil loss and runoff were studied to understand the effect of agroforestry practice on soil carbon loss. Soil property at Lugu Township, Henglu, Chusiang, Dalun, and Lienhuachih 8 sites were analyzed. Soil is clay loam or sandy loam in texture, with organic matter average between 0.5%~9.3%. The bulk densities are 1.03~1.53 g cm-3 in average. The precipitation, surface soil runoff amount, and soil carbon loss at different sites are as following: 2475.5 mm, 0.113 mm, 0.054 ton/ha at Dalun; 3084.5 mm, 0.185 mm, 0.028 ton/ha at Henglu; 2791.5 mm, 0.478 mm, 0.073 ton/ha at Chusiang. The more the precipitation, the more soil loss.
To establish a viable model and evaluation criteria of domestic tree planting for carbon sequestration, the possibility of domestic tree planting for carbon sequestration and carbon standards was evaluated according to the “Directions for Promoting GHG Early Action Project and Offset Project” of Environmental Protection Administration. The results suggest evaluation report from verification organization is lack if official application will be submitted to EPA. There is no restriction of verification organization at the stage of method evaluation. However, when at the stage of examining offset project, calculation method verification qualification is necessary. If EPA follows CDM, a certification authority should be invited to test the ability of the verification organization to avoid delay. Nevertheless, this method needs the communication and confirmation of EPA. Otherwise, verification organizations will face challenges when examining offset projects. Plains forest and agricultural land forest, started as early as 2002, is fully qualified to apply for offset project. It should be the model of tree planting for carbon sequestration.