Spatial variation of alpine timberline altitude on northern slope of Tianshan Mountains is confirmed by remote sensing and field survey data,and its eco-geographical characteristics are analyzed in this study.Results show that：（1） The altitude of alpine timberlines is between 2 600 m and 2 850 m.It ascends gradually from west to east,and changes significantly from Qitai to Balikun.The width of alpine timberlines in Ili and Manas is wider than that in other regions.（2） The altitude of alpine timberlines is controlled by growing season temperature,i.e.annual biotemperature,mean temperature for the warmest month,mean temperature for growing season.The parameter of annual biotemperature is better to indicate the altitude of alpine timberline than other parameters.The values of parameters are all within the range of the average values across China.The main factor influencing forest development in Bayinbuluk is low temperature and drought in winter.（3） The contents of organic matter,total nitrogen and total phosphorus in the timberline ecotones of Ili and Manas are higher than in other timberline ecotones.The Fukang timberline is the turning point of soil acidity and alkalinity,westwards soil is acid and eastwards is alkaline.Soil nutrients mainly exist in the surface layer（0—10 cm）,low and no significant difference in the deep layer（30—80 cm）,showing significant surface-convergence phenomenon.The change of pH value of deep soil from west to east is from weak acid to weak alkaline.The spatial variability of electric conductivity is significant,but there is no distinct difference among different layers.
northern slope of Tianshan Mountainsalpine timberlineclimatic parameterssoil propertiesPicea schrenkiana
NETL
NSTL
万方数据
维普
