侧柏树干边材液流空间变化规律  

Spatial variation pattern of Platycladus orientalis stem sap flow

作　　者：刘德良[1] 李吉跃[2] 马达[2] 

机构地区：[1]嘉应学院生物系,广东梅州514015 [2]北京林业大学省部共建森林培育与保护教育部重点实验室

出　　处：《生态学杂志》2008年第8期1262-1268,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(30070637);国家高技术研究发展计划资助项目(2002AA2Z4281)

摘　　要：利用热扩散探针配合自动气象站，于2005年在北京林业大学妙峰山试验林场对侧柏树干边材液流指标空间变化规律进行了研究。结果表明：侧柏树干不同高度边材液流速率随树干高度的升高而增加，而且高层液流峰值的出现时间要比低层早，高层液流曲线尖窄，曲线斜率大，低层液流曲线变化缓慢，曲线斜率小。不同高度的平均液流速率峰值：6．6m处为0．015cm·s-1，4．6m处为0．009cm·s-1，2．6m处为0．006cm·s-1，0．6m处为0．003cm·s-1；无论是液流速率还是连日耗水量，不同直径的单株均表现出沿直径的增加而增加，但液流速率随直径的变化并不是线性的；土壤的含水量限制了树木的耗水能力，日平均液流通量与土壤含水量呈现良好的S型关系，其中与土层20～40cm层关系更为密切；不同气象因子对树干的液流影响方式不同，太阳辐射强度、大气温度和风速与液流指标呈正相关，并且属于第一主分量，对液流的影响较为直接，空气相对湿度和土壤温度与液流指标呈负相关，属于第二主分量，对液流的影响较为缓慢。通过多元线性回归，得出各气象因子和液流相关性均比较高，说明通过气象因子对树干液流进行预测是切实可行的。With the aid of TDP （thermal dissipation sapwood flow velocity probe） and auto-meteorological station, the spatial variation pattern of Platycladus orientalis stem sap flow in Miaofeng- shan Experimental Forest Farm of Beijing Forestry University was studied in 2005. The results showed that the sap flow velocity （SFV） increased with increasing trunk height, and the peak time of sap flow appeared earlier at upper trunk part than at lower. The sap flow curve was narrower and sharper, and the curve slope was greater at upper trunk part than at lower part. The average maximum SFV at the trunk heights of 6. 6, 4.6, 2.6, and 0.6 m was 0. 015, 0. 009, 0. 006, and 0. 003 cm·s-1, respectively, in July 2005. Both the SFV and the water consumption amount of different diametric single trees were increased with increasing diameter, but the change of SFV was not linear. Soil water content limited the water consumption capacity of the tree, and the sap flow flux had a distinct exponential correlation with soil water content, especially in 20-40 cm soil layer. Different meteorological factors had different effects on the stem sap flow. Radiation intensity, air temperature, and wind speed were positively correlated to the sap flow index belonged to the first principal component that affected the sap flow directly; while air relative humidity and soil temperature were negatively correlated to the sap flow index belonged to the second principal component that affected the sap flow slowly. By stepwise regression, a multi- ple linear equation describing the relationships between sap flow and meteorological factors was established, and it was feasible to use meteorological factors to forecast stem sap flow.

关 键 词：侧柏 边材液流速率 空间变化 

分 类 号：S791.38[农业科学—林木遗传育种]