树形管道模型原理

本文简介了树形管道模型的基本理论,并对若干问题进行了讨论。作者认为比管道长L将随分层厚度△Z的增大而增大,Yukihiro等6]所给出的关系式L_a/L_b=b/a(L_a和L_b分别是△z=a和△z=b时的L值)是有疑问的。

The Pipe Model Theory of Tree Form (A Review)

The authors here introduce the pipe model theory and discuss some questions related to this model. Defining the gradients(L) of equation F(z)=LC(z) when the thickness of stratum △Az=a and △z=b as L_a and L_b, respectively, C. Yukihiro et al (1988) gave the relationship between L and △z: La/Lb=b/a. The authors do not think that this relationship is correct. According to the definition by the references (1～4), the density of the non-photosynthetic tissue C(z)]contained in a horizontal layer of the thickness △z above a ground area A, C(z)=W(z)/(A.△z)(W(z)is the quantity of the non-photosynthetic tissue in the same layer above a unit area. The authors consider that C(z) will decrease when △z increases, so the specific pipe length L will increase with △z increasing. The authors suggest a method to calculate C(z) as follows: Calculate T_b(z) , the total biomass of the non-photosynthetic tissue above the z-horizon, by accumulating the data measured in the layers above z-horizon, and find out the T_b(z)—z curve equation, and obtain the C(z)—z curve equation by derivation C(z)=dT_b/dz]. Then, the C(z) at any depth z can be calculated. Because T_b(z), which just corresponds to z, is not related to △z, C(z), as well as L, will not vary with △z. But in this case, the F(z)—C(z) line may not always be a straight line.