Abstract: We assessed the eco-environmental quality in Wuwei and Minqin oases of Shiyang River Basin based on the Landsat TM/OLI images in 1995, 2006, and 2016. Remote sensingecological distance index (RSEDI) was used to assess the eco-environmental quality, which was calculated by several indices, including desertification index (DI), generalized difference vegetation index (GI), salinization index (SI), and wetness index (WI). The results showed that the ecological quality of Wuwei and Minqin oases was enhanced from 1995 to 2016, with the mean RSEDI increasing from 5.3 in 1995 to 14.8 in 2016. The area of ecological restoration was larger than that of ecological degradation. Spatially, the eco-environmental quality of Minqin oasis was overall in recovering mode. In contrast, the Wuwei oasis exhibited the recovering mode in the northwest region but the degrading mode in the southeast region. Among the three years examined here, the eco-environmental quality of the two oases in 1995 was poor based on the changes in profile map, with a significant spatial discrepancy. In 2006, the eco-environmental quality was the worst among the three years and its discrepancy was the least. The eco-environmental quality was the best in 2016, with significant spatial discrepancy. In general, the eco-environmental quality in the two oases of Shiyang River Basin has been significantly improved by the environmental rehabilitation in the recent decade.

Key words: target tree species, competition, selective cutting, mixed broadleaved-Korean pine forest., key tree species