| 英文摘要： |
The vertical distribution of vegetation in Heihe River Basin has presented a significant dynamic change in the different elevation zones since the 1980s. To explore the dynamic patterns of vegetation types located in the different elevation zones of Heihe River Basin, this study collected 440 field sampling datapoints of vegetation types, remote sensing images, climatic observation data, and DEM and preprocessed them. On the basis of the vegetation distribution and the terrain characteristics of Heihe River Basin, this study classified the vertical distribution of vegetation in Heihe River Basin into six vegetation zones, namely, the oasis farmland and desert zone, desert-steppe zone, dry scrub-steppe zone, mountain forest-steppe zone, subalpine scrub-meadow zone, and alpine cold desert-meadow zone. Moreover, the mean annual biotemperature (MAB) and total annual average precipitation (TAP) were used to analyze the relationship between vegetation change and climate change in the different elevation zones. The results show that the change rate of vegetation was up to 25.75% in Heihe River Basin. The area of vegetation that changed in the oasis farmland and desert zone was the largest (7224 km(2)), and the rate of vegetation that changed in the mountain forest-steppe zone was up to 56.93%. The mean annual biotemperature (MAB) and total annual average precipitation (TAP) in the six elevation zones showed an increasing trend, in which the increased rate of TAP presented a downward trend with the increase of elevation, and that of MAB showed a continuous upward trend with the increase of elevation. The change rate of vegetation was generally higher than that of MAB and TAP in the low and middle vegetation zones. The influence intensity of human activities on vegetation change in the lower and middle elevation zones of Heihe River Basin was greater than that in the high elevation zone between the 1980s and the 2010s. MAB is the major impact factor to vegetation change in the alpine cold zone of Heihe River Basin. |
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