油松树干边材液流空间变化规律  

Spatial Variation of Sap Flow of Pinus tabulaeformis

作　　者：刘德良[1] 

机构地区：[1]嘉应学院,梅州514015

出　　处：《东北林业大学学报》2008年第5期15-18,共4页Journal of Northeast Forestry University

基　　金：国家自然科学基金(30070637);国家高技术研究发展计划(“863”计划)(2002AA2Z4281)资助项目

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油松树干边材液流指标空间变化规律进行了研究。结果表明：油松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比低层早,高层液流曲线窄、斜率大,低层液流曲线变化平缓、斜率小。树干不同高度的平均液流速率峰值为：6.6m处为0.0013cm·s^-1,4.6m处为0.0010cm·s^-1,2.6m处为0.0006cm·s^-1,0.6m处为0.0003cm·s^-1。在树木生长正常的情况下,无论是液流速率还是连日耗水量,不同直径的单株树干液流都随直径的增加而增加（树干直径和边材面积与日平均液流速率和平均耗水量相关分析表明,除油松直径与液流速率的相关系数为0.867之外,其它相关性都在0.9以上,差异性极其显著）,但其变化并不是线性的,在一定范围内,相差一个径阶,液流速率并无明显的变化。土壤的含水量极大地限制着树木的耗水能力,日平均液流通量与土壤含水量呈现良好的指数关系：y=0.597e25.154x（决定系数R2=0.8999）,其中,20-40cm土层的这种关系更为密切。不同气象因子对树干的液流影响方式不同：太阳辐射、大气温度、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。多元线性回归分析表明：各气象因子和液流相关性都比较高,通过气象因子可以预测树干液流。T-DP （Thermal Dissipation Sapwood Flow Velocity Probe） and auto-meteorological station were applied to study the spatial variation of sap flow of Pinus tabulaeformis in Miaofengshan Forest Research Station of Beijing Forestry University. Result shows that the sap flow velocity increases with its trunk height increasing. The peak time of upper sap flow occurs earlier than the lower sap flow, and the curve of upper flow is narrower and its slope is greater compared with the lower sap flow. The average sap flow velocities at different trunk heights were 0. 001 3 cm·s^-1 （6.6 m）, 0.001 0 cm·s^-1 （4.6 m）, 0.000 6 cm·s^-1 （ 2.6 m） and 0. 000 3 cm·s^-1 （ 0.6 m） respectively in July, 2005 ; Under normal growth conditions, whether the sap flow velocity Or the amount of consumption water of tree stem of P. tabuIaeformis with different di- ameters increases with its diameter increasing. Analysis of variance among diameter, sapwood area and index of sap flow velocity shows that their correlations reach significant level, but their changes are nonlinear. If the diameter difference of the trees is within a diameter grade, the sap flow velocities change insignificantly. Soil water content determines the general level of the sap flow, while the meteorological factors affect the instantaneous variability. There is a distinct exponential correlation between soil water content and sap flow fluctuation of Pinus tabulaeformis, and more close relations exist in 20 - 40 cm soil layers. Among the meteorological factors, the sun radiation intensity, atmospheric temperature and wind speed are positively related to the sap flow index, which belong to the first primary component affected the sap flow directly; while the relative air humidity and soil temperature are negatively related to the sap flow index, which belong to the second primary component affected the sap flow slowly. A multiple linear equation between meteorological factors and sap flow was established by stepwise regression and regression testing.

关 键 词：油松 边材液流速率 空间变化 

分 类 号：S791.25[农业科学—林木遗传育种]