新疆的天然林资源保护工程自2000年12月正式启动,截至研究期已历时16年。为监测保护区内林地面积和林地类型的变化、本研究对天保工程在本区域的实施成效予以评价,以期为林区下一阶段保护和经营措施提供数据支持。方法:采用有林地面积、疏林地面积、灌木林地、其他类型地类面积等指标反映林地类型的变化;选取天保工程初期2000年Landsat7 ETM+和末期2016年Landsat8 OLI两个时期的数据,采用最大似然分类技术、混淆矩阵等方法,对林地类型变化区域分布、各分林场林地类型变化趋势和变化原因进行分析。2016年总体分类精度为90.68%,卡帕系数为0.87。结果:1)2000—2016年,林区有林地面积增加35 234.2hm²;2)疏林地面积减少252 355.2hm²;3)灌木林地面积增加244 606.3hm²,其他类型地类面积减少27 485.2hm²;4)2016年相比2000年同期,各分局有林地地面积变化趋势如下:阿勒泰分局有林地面积增加9.6%、布尔津分局有林地面积增加11.7%、富蕴分局有林地面积增加5.9%、哈巴河分局有林地面积增加20.8%、福海分局有林地面积增加22.9%、青河分局有林地面积增加12.5%、两河源自然保护区有林地面积减少7.5%。结论:天保工程区林地变化总体呈良好发展的趋势,天保工程实施成果较明显,但是林区的林地类型分布仍存在不均衡的状况,有林地、疏林地面积占比较小,灌木林、其他类型面积占比较大,在将来的森林保护工程中应加强对有林地、疏林地的保护。

The Natural Forest Resources Protection Project in Xinjiang was launched in December 2000. It has lasted for 16 years as of the research period. This study provides data support for monitoring the changes of forest land area and types,exploring the changing trend of forest area,objectively evaluating the implementation effect of the natural protection project in the region,and implementing the protection and management measures in the next stage of forest area. Such methods as the area of woodland,sparse woodland,shrub woodland and other types of land were used to reflect the changes of forest land types. Based on the data of Landsat7 ETM + in 2000 and Landsat8 OLI in 2016,the regional distribution of forest land type change,the trend of forest land type change and the causes of change were analyzed by using maximum likelihood classification and confusion matrix. In 2016,the overall classification accuracy was 90.68%,and the Kappa coefficient was 0.87. The results showed that:(1)from 2000 to 2016,there was an increase in woodland area:35 234.2 hm²;(2)The area of sparse woodland decreased by 252 355.2 hm²;(3)The area of shrub land increased by 244 606.3 hm²,and other types of area increased by 27 485.2 hm²;(4)compared with the same period in 2000,the change trend of forest land area in 2016 was as follows:the forest land area in Aletai Branch increased by 9.6%,Burjin Branch increased by 11.7%,Fuyun Branch increased by 5.9%,Habahe Branch increased by 20.8%,Fuhai Branch increased by 22.9%,Qinghe Branch increased by 12.5%,but the area of forested land in Two-river Source Nature Reserve decreased by 7.5%. The forest land change in Natural Forest Protection Project(NFPP)area shows a good development trend in general,and the results of the implementation of NFPP are good obviously. However,the distribution of forest land types in forest areas is still unbalanced. The proportion of woodland and sparse forest land is small. The proportion of other types of forest land and shrub land is large. The protection of sparse forest land should be strengthened in future forest protection projects.