近30a安吉县毛竹林动态遥感监测及碳储量变化

Remote sensing-based dynamic monitoring of moso bamboo forest and its carbon stock change in Anji County

通过最大似然分类法从不同时期陆地资源卫星Landsat-5 TM影像中提取毛竹Phyllostachys pubescens林信息,利用变化幅度和动态度2个指标对浙江省安吉县近30 a毛竹林面积时空动态特征进行了监测、评价与分析,并初步估算了各时期竹林地上总碳储量变化情况。结果表明：①各个时期影像分类总体精度和毛竹林信息提取的精度比较好,其中总体分类精度都在85%以上,而毛竹林Kappa系数为0.80~0.95。遥感估算的毛竹林面积与森林资源清查结果相吻合,两者决定系数（R2）达到0.981;②1986-2008年期间,除昆铜乡毛竹林面积呈负增长外（变化幅度为-8.49%）,其他各乡镇的毛竹林面积呈上升趋势,变化幅度为14%~86%,以孝丰镇增长幅度最大,天荒坪镇增长幅度最小;③针叶林、阔叶林以及农业用地的变化对毛竹林总面积增加的贡献最大;④根据毛竹林动态监测结果和毛竹林地上碳密度（20.297 Mg.hm-2）估算得到1986,1991,1998,2004和2008年5个时期安吉县竹林地上碳储总量分别为1.106,1.213,1.327,1.413和1.466 Tg,呈逐渐增加趋势。

Maximum likelihood classification method was used to extract moso bamboo（Phyllostachys pubescens） forest from multitemporal Landsat-5 Thematic Mapper（TM） images.The dynamic change of bamboo forest areas in Anji County,Zhejiang Province in the past 30 years was conducted.Meanwhile,total aboveground carbon stock of bamboo forest was estimated.The results showed that（1） overall classification accuracy for each TM image was over 85%,and Kappa coefficient for moso bamboo forest ranged from 0.80 to 0.95.The relationship between moso bamboo forest area estimated from remote sensing and the forest inventory data was significant with a R2 value of 0.981;（2） during 1986-2008,bamboo forest areas were increased with highest rate of 86% in Xiaofeng and lowest rate of 14% in Tianhuangping,except Kuntong with decreased rate of 8.89%;（3） the increase of moso bamboo forest area in Anji County during the past 30 years was at the expense of conifer forest,broadleaf forest and farmland;（4） according to classification results and aboveground carbon density of moso bamboo（i.e.,20.297 Mg·hm-2）,the aboveground carbon stock was 1.106 Tg in 1986,1.213 Tg in 1991,1.327 Tg in 1998,1.413 Tg.in 2004 and 1.466 Tg in 2008,respectively.[Ch,2 fig.4 tab.31 ref.]