关键词: 乌孙山, 游动分割窗技术, 海拔, 植被, 分布格局

Abstract: Based on field investigation into community important values and the species numbers along elevation gradient from 1 410 m to 2 960 m on the north slope of Wusun Mountain in Yili River Basin of Xinjiang, the altitudinal pattern of plants distribution was discussed by means of the moving split-window technique. The results showed the distance coefficients, such as Squared Euclidean Distance, Mahalanobis Distance and Bray-Curtis Distance can all indicate types, location and width of the community ecotones, especially the Squared Euclidean Distance and Mahalanobis Distance were the best indices showing the variation of plants distribution along the elevation gradient. Calculation using the moving split window technique with different window width suggested 8 plots were the best window width. According to the result from the moving split window calculation, the plant communities on the north slope of Wusun Mountain were classified as 11 types along elevation gradient from the low to the high, as follows: desert steppe, the ecotone between desert steppe and mountain pasture, mountain pasture, the ecotone between mountain pasture and subalpine meadow, subalpine meadow, the ecotone between subalpine meadow and alpine meadow, alpine meadow, the ecotone between alpine meadow and needle-leaved forest, needle-leaved forest, the ecotone between needle-leaved forest and high cold meadow, and high cold meadow. The ecotones between desert steppe and mountain pasture, mountain pasture and subalpine meadow, as well as subalpine meadows and alpine meadow are gradual ecotones, which spanned 250 m, 100 m and 100 m, respectively; The ecotones between alpine meadow and needle-leaved forests, as well as needle-leaved forests and high cold meadow are abruptly-changing ecotones, which spanned 150 m and 100 m, respectively.

Key words: Wusun Mountain, moving split window technique, elevation, plant, distribution pattern