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

点击翻译按钮获取中文摘要

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)