Studies on assessment procedure about wetland restration project using stable isotope ratio

本研究的目的是调查大碧江口三角洲的植被变化和地形特征，并将这次(2001)和过去的植被图(1974,1995,1984)进行比较。利用1974年、1984年、1995年和200年的植被图调查了沙洲北部的地理特征变化，以及1974年小溪与海滨相连的沙洲北部。但在2001年，它因沙子沉积而部分关闭。至于南部沙洲，1974年确定了南部黑松群落的分布，但200年黑松群落的一部分被侵蚀。从1974~2001年对沙洲进行了扩展。与1974、1984、1995和200的植被图相比，1974~2001年扩大了后滩植被的面积。(景观生态学9(2)：27-32,2005)2003年仲夏，我们同时测量了日本沿海泻湖两个典型边缘地带--沙质海岸和盐沼的二氧化碳(CO_2)、甲烷(CH_4)和一氧化二氮(N_2O)的通量。我们的目标是量化温室气体(GHGs)的净通量，并检查控制这两个地点温室气体通量变化的关键因素。沙岸和盐沼的CO2和CH4净通量差异显著，沙质海岸的CO2和CH4净通量的大小和变化均小于盐沼。同时，两个测点NETN2O通量的大小和变化趋势基本一致。在沙质海岸，三种温室气体通量的时空变化受天文潮汐引起的水位波动高度控制。在盐沼，3种温室气体通量的空间变化与地上生物量相关，CO2和CH4通量的时间变化与土壤温度相关。根据观测到的温室气体通量粗略估计的全球变暖潜力总和，盐沼地区大约是沙质海岸的174倍。(化学圈68：597-603)

This research aims at investigating about vegetation changes and topographic feature in the delta of Obitsu estuary, while comparing this time (2001) and the past vegetation maps (1974,1995,1984). The result investigated about change of geographical feature using the vegetation maps in 1974,1984,1995 and 200, as for north sandbar, the creek connected with seaside in 1974. But it was closed a part by deposition of sand in 2001. As for south sandbar, the distribution of Pinus thunbergii community was confirmed on the south in 1974,but a part of Pinus thunbergii community was eroded in 200. The sandbank was expanded from 1974 to 2001.The result compared with vegetation maps in 1974,1984,1995 and 200,the area of the back marsh vegetation was expanded from 1974 to 2001.(Landscape Ecology 9(2):27-32,2005)We measured fluxes of carbon dioxide (CO_2), methane (CH_4), and nitrous oxide (N_2O) simultaneously in two typical fringing zones, sandy shore and salt marsh, of coastal lagoon, Japan, in mid-summer 2003. Our aim was to quantify net the greenhouse gases (GHGs) fluxes and examine key factors, which control variation of the GHGs fluxes in the two sites. Net CO_2 and CH_4 fluxes were markedly different between the two sites; magnitudes and variations of the both fluxes in sandy shore were lower than those of salt marsh. Meanwhile, magnitude and variation netN_2O flux in the two sites were similar. In sandy shore, temporal and spatial variation of the three GHGs fluxes were highly controlled by water level fluctuation derived from astronomic tide. In salt marsh, spatial variation of the three GHGs fluxes were correlated with aboveground biomass, and temporal variation of CO_2 and CH_4 fluxes were correlated with soil temperature. The sum of global warming potential, which was roughly estimated using the observed GHGs fluxes, was ca. 174-fold higher in salt marsh than in sandy shore. (Chemosphere 68:597-603)