论文部分内容阅读
湿地松是我国引种成功的速生用材树种之一,从七十年代开始,南方省区进行了大面积造林。为了实现速生丰产,我们对湿地松幼林的生长节律进行了三年的系统观测。一、观测地自然概况观测样地设在璧山县东风林场的乌牛坡湿地松幼林内。地理位置为东经106°14′26″,北纬29°34′45″,海拔400米。气候属四川盆地东南部长江河谷亚热带湿润区。据县气象站25年资料均值:年均气温17.9℃,最高气温40.6℃,最低-3℃。10℃以上年有效积温5,768℃;年
Slash pine is one of the fast growing timber species introduced in China. Since the 1970s, large area afforestation has been carried out in the southern provinces. In order to achieve fast-growing and high-yielding, we systematically observed the growth rhythm of young Pinus elliottii for three years. I. Natural Overview of the Observed Land The observation sample is located in the young forest of Pinus elliotottii in Dongfeng Forest Farm, Bishan County. Its geographical location is 106 ° 14’26 “east longitude and 29 ° 34’45” north latitude with an elevation of 400 meters. The climate belongs to the subtropical humid zone of the Yangtze River valley in southeastern Sichuan Basin. According to the county weather station 25 years data mean: average annual temperature of 17.9 ℃, the maximum temperature of 40.6 ℃, the lowest -3 ℃. 10 ℃ above the effective accumulated temperature 5,768 ℃; years