The Growth Evaluation & Climate Analysis Of Introduced Pinus Ponderosa In China

To analyze the 13 climate factors(Annual average temperature, Extreme temperatures, Frost-free period, Annual sunshine hours, average wind speed, Annual average relative humidity and rainfall, etc) in 35 Pinus ponderosa introduction sites of China by using Principal Component Analysis, Cluster Analysis and Correlation Analysis showed that the Low temperature factors (Average annual temperature, Coldest month average temperature, Minimum temperature, Frost-free period,≥10℃of accumulated temperature, Annual sunshine hours, Annual average relative humidity)are more important than the High temperature factors (Hottest monthly temperature, Average altitude in rainfall, Extreme maximum temperature, Annual average wind speed). The Humidity factor is also the important elements in the weighting factors. In the plant introduction and acclimatization process, the Low temperature factor may become limiting factor for introduction of Pinus ponderosa. If the High temperature combined with drought, will also be the key factor in Pinus ponderosa introduction.Average annual tree height increment of Pinus ponderosa is positively related with Warmest month average temperature, Extreme maximum temperature, Annual sunshine hours, Annual evaporation; and is negatively correlated with Average annual temperature, Coldest month average temperature, annual rainfall, Extreme minimum temperature, Frost-free period,≥10℃accumulated temperature, Annual average wind speed and annual relative humidity. The two closely related climatic factors (Annual rainfall and Average relative humidity) with Average annual tree height increment for spatial analysis showed that the maximum tree height increment of Pinus ponderosa (>0.35m.) appears in a relatively small rainfall (about 400mm) with a average relative humidity around 80-70%.Average annual diameter increment of Pinus ponderosa is positively related with Hottest monthly temperature, Extreme maximum temperature, Annual sunshine hours, Annual evaporation; and is negatively correlated with Annual temperature, Coldest month temperature, Rainfall, Extreme minimum temperature, Frost-free period,≥10℃accumulated temperature, Annual average wind speed and annual relative humidity. The two closely correlated climatic factors (Annual rainfall, Average relative humidity) with Average annual diameter increment for spatial analysis showed that maximum average diameter increment of Pinus ponderosa (>0.45cm) appears in a relatively smaller rainfall (about 400mm) with a 70% average relative humidity.Growth quality index of Pinus ponderosa is positively related with Hottest monthly temperature, Extreme highest temperature, Annual evaporation; and is negatively correlated with Annual temperature, Coldest month temperature, annual rainfall, Extreme minimum temperature, Frost-free period,≥10℃accumulated temperature, Annual sunshine hours, Annual average wind speed, and annual average relative humidity. The two closely correlated climatic factors (Annual rainfall, Average relative humidity) with Average annual diameter growth for spatial analysis showed that the maximum growth-quality index of Pinus ponderosa is greater than 0.10 which appears in a relatively smaller rainfall (around 400 mm) with a higher average relative humidity (about 70%).Basing on growth-index, the 35 introduction sites for Pinus ponderosa in China can be divided into three areas:Best growing area> better growing area> survival area.The best area(Pinus ponderosa is growing fast without any disease and pests) for introduced Pinus ponderosa in China are Beijing, Hebei, Shanxi, Shaanxi, Gansu et al. around loess plateau with a Growth-quality indicator greater than 0.03.The introduction sites with growth-quality indicator ranging from 0 to 0.01 are the survival area for Pinus ponderosa in China including Nanjing, Jiangxi Lushan, Changchun, Shenyang, Zhejiang, Shanghai, Hubei Wuchang, and Changsha. et al.The other places are the Pinus ponderosa growing better area with growth-quality indicator ranging between 0.01 and 0.03.