CAJ | 학술논문

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 5x3-7.295 5x2+3.682 6x+0.567 4 (R2=0.939 1, n=80, P=0.01)河头: y=5.006 2x3-9.116 1x2+4.454 4x+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.
수액류동밀도(SFD)수변재경향심도적변화대우준학고측류경변재적수액통량시비상중요적,후자우제약착Heat Pulse적응용정도.단흘금위지,지유흔소적연구고계료유우SFD수경향적제도변화이대래적오차,SFD연수간경향분포규률적획득왕왕의고대소수궤과수적관측자료.기우재엄동뇌주반도대량괴3～4년생안수(Eucalyptus urophylla S.T. Blake)인공림1년적Heat Pulse관측,탐토료대래자39주립목대량관측자료적종합처리방법,발현저량개양지(기가화하두)적림분중SFD수변재경향심도적변화가이용여하회귀방정래묘술:기가: y=3.667 5x3-7.295 5x2+3.682 6x+0.567 4 (R2=0.939 1, n=80, P=0.01)하두: y=5.006 2x3-9.116 1x2+4.454 4x+0.463 4 (R2=0.806 9, n=72, P=0.01)식중:y--모일수액감응기소측득적SFD여불동심도적4개감응기소측득적SFD적평균치지비;x-모일수액감응기재변재중적심도여변재후도지비.종형성층도심재,SFD최초유소증가,수후지속감소,단유우수목년령흔소,최대적SFD지비최소적SFD대0.33～0.36배.
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 5x3-7.295 5x2+3.682 6x+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 2x3-9.116 1x2+4.454 4x+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.