标题: 对太阳辐射的拦截叶形状的影响 The effect of leaf shape on the interception of sol [打印本页] 作者: ゞ_轻描丶幸福的 时间: 2014-12-8 17:09 标题: 对太阳辐射的拦截叶形状的影响 The effect of leaf shape on the interception of sol The effect of leaf shape on the interception of solar radiation 7 p! |# f! X% M4 l- }) \; G9 Z- nC.B.S. Teh* , E* O% ^" A! ^9 u( [0 jDepartment of Land Management, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, 4 U3 {6 S" f, u4 ~Malaysia5 [/ ]7 G. L( Y/ X) u
5 Abstract0 Z c, e+ a1 _: k( D
One of the properties of canopy architecture is leaf shape, and its effect on solar radiation* G4 @/ o* J1 w, Y2 D9 ?" k: E5 t5 P
interception by a plant is little understood and studied. Consequently, this study was to evaluate3 U- h- L- m5 `0 q$ e7 ~
the effect of six leaf shapes on both direct and diffuse solar radiation interception using a $ T: @ H* w4 s" \3 l+ p; |detailed 3-D solar radiation model. Six hypothetical plant prototypes were computer-generated- @ v' ^' O/ T1 Q8 @" e
10 so that each prototype was equal to each other in all aspects; only the leaf shape for each 7 L7 z4 ^; l, D, t' Hprototype was varied. The leaf shapes selected were round (RD), square (SQ), triangle (TR), 1 `- ]0 a. S; u" l* @3 Xinverted triangle (ITR), ellipse (EL) and lobe (LB). Computer simulations revealed that leaf- K5 l- U& F4 u" e& u! I1 M$ e
shape did have an effect on direct and diffuse solar radiation interception. However, its effect* ~+ ]9 H! u5 q
was to a rather small extent of not more than 11% increase in solar radiation interception. The4 v( e" s% g, O& P* g6 |: ^
15 mean hourly interception of solar radiation by the prototypes decreased in the following ; ?! j% |& S1 q2 ~, I! b, }4 H. omanner: (ITR ≈ EL) > (RD ≈ SQ ≈ TR ≈ LB). Although leaf lobbing is often hypothesised to 5 o( y! ?3 v }+ E* Vproduce deeper sunflecks within the canopy, this study however revealed that leaf lobbing per - w" @/ e6 G+ H# F% Ose had no effect on solar radiation interception. All properties being equal, solar radiation/ D" u' g7 L, A* e" E! X; Z7 D
interception could be increased by having leaf shapes that are: 1) long and narrow, 2) broader at1 t5 F& L8 L) k/ j
20 the apex than at the basal, and 3) supported by leaf petioles. These three conditions increase0 x( Z; @2 C0 |7 m# U
solar radiation interception by causing the canopy to be spread out more uniformly in the aerial5 S9 a' E6 S* ]5 v+ }4 A2 q
space; this, in turn, means less leaf clustering and self-shading. However, the effect of leaf 9 m0 W N2 `1 Qshape on solar radiation interception decreases for near or full canopy cover because at this . |4 e0 r! m0 d" Mstage, the canopy is already intercepting solar radiation at near maximum capacity. Leaf shape' z5 q+ j7 M3 U- n e6 {
25 also did not affect the diurnal variation of direct and diffuse solar radiation interception. This+ ]4 K4 J9 C* g) F
study may help to better select crop varieties having the “proper leaf form” for optimum plant 4 d1 ~7 p4 U$ O5 U% Xproduction, as well as to better understand plant adaptation mechanisms in response to |1 X- D, e0 _6 r7 f8 J- Nenvironmental stresses.0 R6 k1 q/ e$ E: p% ~
Keywords: leaf shape; solar radiation; Beer’s law; canopy architecture 9 [% d. _1 Y. e( t6 j( [. {7 p0 e/ P' `* W* C/ @' V( }' G T# P
leafshape.pdf
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