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 . g1 O. q! d) bC.B.S. Teh*% `% o* |0 m' g9 a1 e' p8 _# A
Department of Land Management, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor,4 O( n- ]: U6 d, }5 ?
Malaysia 6 b9 c2 }1 B+ J( s5 M/ Q( b- q1 T/ p5 Abstract. k6 D% ]) u" C" T( R2 ~( j
One of the properties of canopy architecture is leaf shape, and its effect on solar radiation - Y" S' w$ l5 f( V+ t1 e9 h7 yinterception by a plant is little understood and studied. Consequently, this study was to evaluate 5 X7 `1 g( O$ K7 [0 [: [1 nthe effect of six leaf shapes on both direct and diffuse solar radiation interception using a( D( w l# b8 y* I
detailed 3-D solar radiation model. Six hypothetical plant prototypes were computer-generated g# P: M& u5 u+ t, ^, t2 A
10 so that each prototype was equal to each other in all aspects; only the leaf shape for each $ ` Y) u ^2 x( Fprototype was varied. The leaf shapes selected were round (RD), square (SQ), triangle (TR), 4 ~& y4 j4 E4 Y! v7 ~" cinverted triangle (ITR), ellipse (EL) and lobe (LB). Computer simulations revealed that leaf; {& O: I5 F: [0 O, t* B1 u$ Q- \
shape did have an effect on direct and diffuse solar radiation interception. However, its effect 9 U: H( h0 t7 D }+ k: I0 X* Ywas to a rather small extent of not more than 11% increase in solar radiation interception. The 5 V/ m R' P% j# W, k6 \15 mean hourly interception of solar radiation by the prototypes decreased in the following/ k7 Z1 N: Z. q% M' C/ y+ p
manner: (ITR ≈ EL) > (RD ≈ SQ ≈ TR ≈ LB). Although leaf lobbing is often hypothesised to6 s) |5 q) T$ ^) h& Q1 l: q
produce deeper sunflecks within the canopy, this study however revealed that leaf lobbing per ! m; y# ~+ i% U) v! \se had no effect on solar radiation interception. All properties being equal, solar radiation ( C2 R' K4 E, `interception could be increased by having leaf shapes that are: 1) long and narrow, 2) broader at / H+ U( |% _# J8 g1 D" n; Y' u8 {7 e20 the apex than at the basal, and 3) supported by leaf petioles. These three conditions increase3 g0 {3 G* r# f P4 A4 b9 Q
solar radiation interception by causing the canopy to be spread out more uniformly in the aerial 9 o; z4 R: C9 ]! ?1 [3 X4 _) bspace; this, in turn, means less leaf clustering and self-shading. However, the effect of leaf ( [/ c1 L) d# l9 F5 _ p7 Jshape on solar radiation interception decreases for near or full canopy cover because at this4 X6 L, g/ }5 `8 U/ G4 o' s; W+ ^
stage, the canopy is already intercepting solar radiation at near maximum capacity. Leaf shape 5 k/ n3 V3 E! j5 V" E25 also did not affect the diurnal variation of direct and diffuse solar radiation interception. This( Q( |2 B8 n8 @1 G$ t* l) r: Y; H
study may help to better select crop varieties having the “proper leaf form” for optimum plant ' t- W J( @4 X/ H, v& J( R- _" x- |production, as well as to better understand plant adaptation mechanisms in response to' H0 y, E9 V( h" E) V3 j7 \
environmental stresses." L7 n, B8 D$ [! J- s- Y
Keywords: leaf shape; solar radiation; Beer’s law; canopy architecture 8 k0 y* Y8 ~1 |2 m' q* _ : M$ t; f) Z( W8 q$ O7 ~' N$ i0 {# C0 o4 q. f
leafshape.pdf
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