Chapter 3 Multiply method Yp=E(2ΣQf(t)f(w)HI E: radiation use efficiency 2Q: sum of radiation within growing season f(t: modifying function of temperature f(w): modifying function of water balance HI: harvest index(ratio of economic yield to biomass.0.35 0.45 for wheat. 0.3-0.4 for soybean 2021/2/22 Assessment of Climate/Change Impacts
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 6 of 46 Multiply method Yp=E•(Q)•f(t)•f(w)•HI =========== E: radiation use efficiency Q: sum of radiation within growing season f(t): modifying function of temperature f(w): modifying function of water balance HI: harvest index(ratio of economic yield to biomass, 0.35～0.45 for wheat, 0.3～0.4 for soybean
Chapter 3 Multiply method 黄秉维: Yp=0.93×Q p: photosynthetically potential productivity(kg/ha) Q: solar radiation (cal/cm2) coefficient:0.93=0(1-β)(1-)(1-a)×b(1-c(1-d e/(1l-6)/(1-f a: percent of PAR, 479 B: transmission of solar radiation, 5% y: percent of solar radiation absorbed by non- photosynthecally organs, 10% 2021/2/22 Assessment of Climate/Change Impacts
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 7 of 46 Multiply method 黄秉维： Yp ＝0.93×Q Yp: photosynthetically potential productivity (kg/ha) Q: solar radiation（cal/cm2） coefficient: 0.93=α(1－β)(1－γ)(1-a)×b(1－c)(1－d) ×e/(1-δ)/(1-f) α：percent of PAR, 47％ β: transmission of solar radiation, 5％ γ：percent of solar radiation absorbed by nonphotosynthecally organs, 10％
Chapter 3 Multiply method a: reflectivity, 6.5 b: energy need for per unit carbohydrates formed, 10 Enstain/ug c: 8.6Enstain/cal e: mass of per unit carbohydrates, 3X10g/ug d: percent of dry matter for respiration, 25% f: percent of dry matter for non-organic, 8% 8: percent of plant moisture 15% 2021/2/22 Assessment of Climate/Change Impacts 8of46
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 8 of 46 Multiply method a：reflectivity, 6.5％ b：energy need for per unit carbohydrates formed, 10 Enstain/g c：8.6Enstain/cal e: mass of per unit carbohydrates, 3×10－5g/g d: percent of dry matter for respiration, 25％ f: percent of dry matter for non-organic, 8％ δ:percent of plant moisture, 15％
Chapter 3 Multiply method-f(t Modified functions for temperature 于沪宁-赵丰收: Ft=4.301×102.t-571×104t2 2021/2/22 Assessment of Climate/Change Impacts
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 9 of 46 Multiply method—f(t) Modified functions for temperature： 于沪宁-赵丰收： Ft＝4.301×10-2 t-5.771×10-4 t 2
Chapter 3 Multiply method-f(t 李世奎: 0.027×t-0.162[6℃,21℃) 0.086×t-1.41 21C,28℃) 28℃,32℃ -0.083×t367[32℃,44℃) (<6℃)(44C<t) EXp.{-2[(t-to)/10 F t凉 Exp.{-[(tt0)10]2} (t>to t: measured temperature to: optimal temperature 2021/2/22 Assessment of Climate/Change Impacts 10of46
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 10 of 46 Multiply method—f(t) 李世奎: 0.027×t － 0.162 [6℃，21℃) 0.086×t －1.41 [21℃，28℃） Ft 温 ＝ 1 [28℃，32℃） -0.083×t+3.67 [32℃，44℃） 0 （t<6℃）（44℃<t） Exp.{-2[(t-t0 )/10] 2} (t<t0 ) Ft 凉 ＝ Exp.{- [(t-t0 )/10] 2} (t>t0 ) t: measured temperature t0 : optimal temperature