Study On Biomass And Carbon Storage Of Different Poplar Agroforestry Patterns

In order to evaluate the function in carbon sequestration of poplar-agrofores trysysterms,a case study was conducted to compare the differences in carbon reserves and the carbon productivity among three poplar-agroforestry patterns in the northern Jiangsu plain.By means of the relative growth method,biomass production models of Populus deltoides cv.'35' were developed.Based on the models biomass and the carbon reserves were estimated and compared among three poplar-agroforestry patterns,and the crop biomass and the carbon net output productivity as well as the soil carbon reserves were also measured and discussed for the different patterns The main results were as follows:1.The fitted biomass production models and their correlation coefficients for various components of clone 35 were W=0.123611×(D²H)^0.804004574(r²=0.957)2.There is significant difference of poplar plantations biomass in three different agroforestry patterns.Aaboveground biomass production of poplar plantations in the different agroforestry patterns are:K-Pattern(12.49 t·hm^-2)＞PPattern (12.25 t·hm^-2)＞W-Pattern(7.75 t·hm^-2);while the underground biomass production were:P-Pattern(2.27 t·hm^-2)＞K-Pattern(2.22 t·hm^-2)＞W-Pattern(1.45 t·hm^-2).3.There is significant difference of Biomass production for different crops in three different agroforestry patterns.Biomass production for different crops in the various patterns were:Wheat,W-Pattern(16.58t·hm^-2)＞K-Pattern(15.24 t·hm^-2)＞PPattern (13.48 t·hm^-2);Rice,W-Pattern(11.65 t·hm·^-2)＞P-Pattern(11.21 t·hm^-2)＞K-Pattern(10.53 t·hm^-2);maize,W-Pattern(13.79 t·hm^-2)＞K-Pattern(9.79 t·hm^-2)＞P-Pattern(8.26 t·hm^-2);soybean,P-Pattern(5.81 t·hm^-2)＞W-Pattern(4.74 t·hm^-2)＞K-Pattern(4.69 t·hm^-2).4.There is significant difference of carbon reserves in three different agroforestry patterns.Carbon reserves of the poplar plantation for the various agroforestry patterns were in the order of K-Pattern 7.37 t·hm^-2＞P-Pattern 7.27 t·hm^-2＞W-Pattern 4.60 t·hm^-2.5.From the views of ecosystem,among the three poplar-agroforestry patterns, the largest reserves of total carbon(poplar+soil+wheat+corn)was measured in K-Pattern,hitting 92.31 t·hm^-2,and the smallest was observed in W-Pattern(poplar +soil+wheat+soybean),only 56.45 t·hm^-2.