Relationship between Geographical Distribution of Pinus yunnanensis and Climate

A distribution map of Pinus yunnanensis was made according to the data on geographical distribution of P.yunnanensis by means of applying geographic information systems software ArcGIS,and the climatic parameters of the distribution areas for P.yunnanensis were determined by the climate forecast model ClimateChina.The relationship between the geographical distribution of P.yunnanensis and the climate was studied by adopting the indexes of Kira including the warmth index(WI),coldness index(CI) and aridity index(K),Xu's humidity index(HI),Holdridge's life temperature(BT),potential evapotranspiration(PET),potential evapotranspiration ratio(PER) and the single factors as the mean annual temperature,the mean temperature in January,the mean temperature in July,the mean annual precipitation,the 5 ℃ accumulated temperature,the 18 ℃ accumulated temperature,the maximum temperature,the minimum temperature,the temperature variation,the ratio of temperature and precipitation of the year,etc.And the Kira's water-temperature indexes on distributional upper limit,low limit and north limit were discussed.The major climatic factors effecting the distribution of P.yunnanensis were screened out by statistical analysis software SPSS and the results showed the impact factors are in the order of temperature humidity the temperature difference between mean warmest month temperature and mean coldest month temperature.