关键词: 林火烈度, 归一化火烧指数(NBR), 环境因子, 过火面积, 遥感, 大兴安岭呼中林区

Abstract: An outdoor culture experiment was conducted to study the growth and nutrient con tents of submerged macrophyte Potamogeton malaianus in Taihu Lake unde r different CO2 concentrations. As affected by elevated CO2 concentration (1 000 μmol·mol-1), the biomass per plant increased by 443% (P<001) , but the shoot biomass decreased by 55% (P<0.05). The N content in root a nd leaf decreased by 181% (P<005) and 64% (P<005), respectively, but that in stem was less affected (P>005). The P content in root, shoot, and leaf increased by 222% (P<005), 266% (P>005) and 388% ( P<005), soluble sugar content increased by 273%, 183% and 375% (P< 005), and total C content increased by 46%, 53% and 20%, respectively. E levated CO2 concentration decreased the N and P concentrations in w ater body by 79% and 51% (P<005), respectively, but had less effects o n the N and P contents in sediment. It was suggested that elevated CO2 concent ration had definite effects on the growth and habitat of submerged macrophytes.

Key words: forest fire severity, normalized burn ratio (NBR), environmental factor, burnt area, remote sensing, Huzhong forest region of Great Xing’an Mountains.