以六盘山为研究区,根据野外植被调查资料、Landsat TM影像和气象数据,利用遥感影像分类方法、回归分析方法等,在研究区从南向北选取三条东西走向的等大、平行样区,系统研究景观格局与主要气候要素之间的关系。结果表明:六盘山地区年平均气温为0.8℃-7.0℃,主要受高程控制,气温直减率为0.51℃/100 m;降水量为599-770 mm,在水平方向上东南多、西北少;在垂直方向上,先随着海拔高度上升而增加,至最大降水高度(2502 m)后呈下降趋势。六盘山地区主要植被类型为暖温带落叶阔叶林,随着南至北降水量的逐步减少,植被类型有从森林经由灌丛草甸向草原过渡的趋势,北部草原成分逐渐增加。因此区域降水条件对西北干旱区的植被格局起到决定性作用。该结论有助于理解气候变化背景下生态系统的响应机理,可为区域生态建设提供理论依据。
Based on Landsat TM Image,vegetation field survey data and meteorological data,we derived the distribution patterns of vegetation types,temperature and precipitation in Liupan Mountains by using image classification methods and regression analysis method. Subsequently,we analyzed the changes of landscape pattern in three transects with different climate conditions. The results showed that the annual mean temperatures in Liupan Mountains vary at different altitudes,ranging from 0.8oC to 7.0oC,(the mean temperature lapse rate is 0.51oC/100m). The annual precipitation ranges from 599 mm in northwest region to 770 mm in southeast region. In the vertical direction,the precipitation tends to increase as the altitude increases and then begin to decrease when the altitude is more than 2502 m. The main vegetation type in Liupan Mountains is warm temperate deciduous broad-leaved forest. However,as the precipitation decreases from southeast to northwest,there is a tendency in vegetation types from forest to steppe. Therefore,precipitation is dominant factor affecting the vegetation landscape pattern in arid area of Northwest China. The conclusion is helpful for people to understand the mechanism of ecological response to climate changes and it can also provide scientific basis for regional ecological construction.