[Spatial patterns of eco-climatic factors on Tibetan plateau]

Based on the 1966-2005 observation data from 113 meteorological stations on the Tibetan Plateau and its surrounding areas, the spatial patterns of mean temperature of warmest month (TWM), mean temperature of coldest month (TCM), duration of mean daily temperature > or = 10 degrees C (DT10), annual precipitation (AP), mean annual potential evapotranspiration (PE), and annual arid index (AI), on the Plateau were analyzed. It was shown that the TWM was 7-20 degrees C, which decreased from eastern surrounding area to the central region, while TCM was--18.4 degrees C to 8 degrees C, being decreased from south to north. The DT10 decreased from eastern surrounding area ( > 150 days) to central region (50 days), and the AP decreased from southeast to northwest. The PE calculated by Thornthwaite model decreased from southeast to northwest, and was 330-750 mm in most parts of the study area. Arid area occupied a larger proportion and mainly located in the northwest of Tibetan Plateau, while humid area was smaller and mainly located in the east and southeast of the Plateau. The vegetation distribution on Tibetan Plateau had good correlations with the test eco-climatic factors, suggesting that these factors could better characterize the vegetation patterns on Tibetan Plateau.