Study On Light Utility Efficiency Of Main Agro-forestry Systems In North Of Jiangsu Coastal Protective Forest

The paper took the Poplar and Metasequoia of coastal protective forest in north of Jiangsu asthe research object.11experimental samples were choosen according to the ages, spacing and thecrops under the tree of local Poplar and Metasequoia.The growing condition, energyaccumulation and light utility efficiency were analyzed from April to November in2011.Theresult show that:(1)According to the parse wood method,fit the growth equation of Poplar and Metasequoia,estimate the growth of different components of trees in different models. The5ages,3×16mPoplar was135.56kg；15ages,3×12m Metasequoia was30.57kg,the size order of differentcomponents was trunk＞branches＞roots＞bark＞leaves;trunk＞roots＞branches＞bark＞leaves.(2) In different models,the order of per unit area biomass accumulation of trees was B(5a,3×16m)＞A(5a,3m×12m)＞D(15a,3m×16m)＞C(15a,3m×12m)＞H(15a,3m×16m)＞F(15a,3m×12m)＞G(5a,3m×16m)＞E(5a,3m×12m).B was the closest to the blank. In differentphenophases,the per unit area biomass accumulation of wheat had significant difference.Inflowering and fruiting stages,the biomass difference of soybean was not significant.In the samemodel,the middle point of line＞the point outside the crown＞the point under the crown,and theeast point under the crown＞the west point under the crown.(3)The trend of LAI and light interception of wheat was the same with the soybean, thetransmittance and LAI of Poplar and Metasequoia had the opposite trend.According to thecorrelation analysis,the correlation coefficients of effective panicles,grain number and1000grains weight of wheat were0.965,0.764,0.860, the correlation coefficients of effectivegrains,pod number and1000grains weight of soybean were0.994,0.888,0.831.(4)The aerial parts caloric value of Poplar and Metasequoia was greater than the undergroundparts. Metasequoia was greater than the Poplar in the same component,the caloric value ofdifferent components of Poplar, Metasequoia, wheat and soybean had different orders,Poplar:branches＞bark＞leaves＞trunk＞roots, Metasequoia:trunk＞bark＞leaves＞branches＞roots,wheat:spike＞stalk＞roots,soybean:pod＞leaves＞stalk＞roots.(5)In different models,the LUE of Poplar was greater than the Metasequoia.The Poplar-cropmodels promoted the LUE more than the Metasequoia-crop.According to the overallanalysis of LUE in different models,the order was: D(0.757%)＞B(0.721%)＞C(0.618%)＞A(0.584%)＞I(0.52%)＞H(0.432%)＞CK(0.39%)＞E(0.388%)＞F(0.365%)＞G(0.314%)...