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核心期刊论文目录 |
Radial Variation in Sap Flux Density as a Function of Sapwood Thickness in Two Eucalyptus (Eucalyptus urophylla S.T.Blake) Plantations |
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| 出 版 社：Acta Botanica Sinica |
| 发表时间：2002 |
| 台 站：
鼎湖山森林生态系统定位研究站
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| 作 者：Zhou Guoyi、Huang Zhihong、J.D.Morris、LI Zhian、John Collopy、Zhang Ningnan、Bai Jiayu |
| 点 击 率：5554 |
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| 关 键 字：径向变化; 树液流量密度; 边材厚度; 桉树 |
| 摘 要： 树液流动密度(SFD) 随边材径向深度的变化对于准确估测流经边材的树液通量是非常重要的,后者又制约着Heat Pulse 的应用精度。但迄今为止,只有很少的研究估计了由于SFD 随径向的梯度变化而带来的误差,SFD 沿树干径向分布规律的获得往往依靠对少数几棵树的观测资料。基于在广东雷州半岛对两块3～4 年生桉树( Eucalyptus urophylla S. T. Blake) 人工林1 年的Heat Pulse 观测,探讨了对来自39 株立木大量观测资料的综合处理方法,发现这两个样地(纪家和河头) 的林分中SFD 随边材径向深度的变化可以用如下回归方程来描述:
纪家: y = 3. 667 5 x3 - 7. 295 5 x2 + 3. 682 6 x + 0. 567 4 ( R2 = 0. 939 1 , n = 80 , P = 0. 01)
河头: y = 5. 006 2 x3 - 9. 116 1 x2 + 4. 454 4 x + 0. 463 4 ( R2 = 0. 806 9 , n = 72 , P = 0. 01)
式中: y ———某一树液感应器所测得的SFD 与不同深度的4 个感应器所测得的SFD 的平均值之比; x —某一树液感应器在边材中的深度与边材厚度之比。从形成层到心材,SFD 最初有所增加,随后持续减小,但由于树木年龄很小,最大的SFD 只比最小的SFD 大0. 33～0. 36 倍。 |
| 关 键 字(英文)：radial variation ; sap flux density ; sapwood thickness ; eucalyptus trees |
| 摘 要(英文)：Radial variation in sap flux density (SFD) as a function of sapwood thickness is of importance in accurately estimating sap flux through sapwood area which , in turn , decides the precision of heat pulse application. However , until now , only a few studies have evaluated the magnitude and significance of sampling errors associated with radial gradients in SFD , which were based on the small monitoring measurement data from a few trees. Based on one year of heat pulse observation of two 3 - 4 years old Eucalyptus urophylla S. T.Blake plantations in Leizhou Peninsula , Guangdong Province ,China , a way of data processing was developed to treat with the lots of SFD data measured from 39 trees. It was found that the radial variation in SFD as a function of sapwood thickness in the two eucalyptus plantation sites could be expressed as y = 3. 667 5 x3 -7. 295 5 x2 + 3. 682 6 x + 0. 567 4 ( R2 = 0. 939 1 , n = 80 , P = 0. 01) ,where y is the ratio of SFD of a sensor to the average of four data in different depths , x is the ratio of a sensor depth to the radial sapwood thickness. It was the same (as in the following equation) in Jijia site , y = 5. 006 2 x3 - 9. 116 1 x2 + 4. 454 4 x +0. 463 4 ( R2 = 0. 806 9 , n = 72 , P = 0. 01) in Hetou site. From cambium to heartwood , SFD showed some increases at first and then decreases continuously. However , because the trees were very young , the maximum SFD was only 0. 33 - 0. 36 times more than the minimum. |
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 Radial Variation in Sap Flux Density as a Function of Sapwood Thickness in Two Eucalyptus (Eucalyptus urophylla) Plantations.pdf
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