Study on Impact of Altitude on Growth Amount of Pinus taeda Stand

Afforestation experiments of introduced Pinus taeda have been conducted at different altitudes in Longli forest farm in Guizhou province.The results of variance analysis and results' comparison show that Pinus taeda's average breast diameter,height,individual timber volume gradually become bigger with lowering of the elevation;while the stand suffers more severely frozen disaster with rising of the elevation.The most damaged stand is at the elevation of 1300m so that partial stand has no longer actual values for its cultivation.Thus,the altitude is the first critical factor for introducing Pinus taeda in middle area of Guizhou.It is unsuitable for developing Pinus taeda above 1300m in the mountains.