广东樟树各器官含碳率及碳储量

Component specific carbon content and storage of Cinnamomum camphora in Guangdong Province

以2012年广东省森林资源连续清查资源数据中樟树Cinnamomum camphora的分布为基础,按2, 4, 6, 8,12, 16, 20, 26, 32和38 cm共10个径阶伐倒90株樟树样木,获取树干、树皮、树叶、树枝、树根各器官生物量及含碳率数据,采用加权平均和总碳储量计算方法,计算了90株单木的碳储量。结果表明:广东樟树平均含碳率为0.509 6;树皮含碳率显著低于其他各器官(P<0.05),树干、树叶、树枝、树根差异不显著;含碳率随年龄增加而增加,到近熟林和成熟林达到最高,到过熟林再下降;人工林的含碳率高于天然林;含碳率随着纬度增加而增加,随着海拔增加而降低;各器官碳储量在全树中的比例从大到小排列顺序为树干,树枝,树根,树皮,树叶;随着胸径增加树干碳储量比例变化的趋势先增加后下降,树皮碳储量比例前期稳定、后期下降,树叶、树根碳储量比例变化不大,树枝碳储量比例初期稳定、后期增加。拟合出樟树年龄(A),胸径(D)和D2H(H为树高)的最优碳储量(Ct)模型依次为Ct=0.019 4A2.652 0, Ct=0.011 8D2.937 6, Ct=0.001 6(D2H)1.268 6, R2值依次为0.602 9, 0.943 2,0.910 5;经交叉检验,模型拟合效果显著(P<0.01)。以胸径和D2H为变量的樟树碳储量模型拟合效果优于以年龄为变量的模型,模型应用中应优先选择胸径和D2H为变量的模型进行碳储量估算,当胸径和D2H不易测量且年龄易知时,方可使用年龄为变量的碳储量模型进行估算。

To quickly and accurately measure the car on sink in forest carbon sequestration projects and to monitor carbon storage changes in forest vegetation of Guangdong Province,Cinnamomum camphora trees were selected as the object to establish a carbon storage model.Based on the 8th continuous forest inventory data for C.camphora distribution in Guangdong Province in 2012,all 90 sample trees were classified in 10 diameter classes according to 2,4,6,8,12,16,20,26,32,and 38 cm.The weighted mean and total carbon storage were calculated for individual trees of C.camphora including components of stem wood,bark,leaves,branches,and roots among different diameter levels by using the analysis of variance (ANOVA) method.Results showed that:(1) The average carbon rate of C.camphora in Guangdong was 0.5096.There were no significant differences among stems,leaves,branches,and roots (P>0.05) for the average carbon content in DBH levels,but the carbon content of bark was significantly lower than other components (P<0.05).(2) Carbon content increased with age in period of mature and near-mature forests,but declined in period of over-mature forests.(3) The carbon content of the artificial forest was higher than the natural forest and increased with increasing latitude,but decreased with the increasing of altitude.(4) The proportion of carbon storage in each component was stem > branch > root > bark > leaf.(5) With an increase in DBH,the ratio of stem carbon storage increased first and then decreased,the proportion of bark carbon reserves was stable at an early age but decreased in later stages,the proportion of leaves and roots changed little,and the carbon storage of branches was stable first and increased in a later period at a significant level of 0.05.(6) The optimal carbon storage(Ct) model of C.camphora and R^2 for age (A) was Ct=0.0194A^2.6520,R^2=0.6029;for DBH was Ct=0.0118D^2.937 6,R^2=0.9432;and for D^2H was Ct=0.0016(D^2H)^1.2686,R^2=0.9105.Through cross validation,the model fitting effect was significant (P<0.01).The fitting carbon storage model of C.camphora with D and D^2H was better than the age vatiable.In the model application,the model with D and D^2H should be selected to estimate the carbon storage.When the diameter (D) and D^2H were not easy to be measured but the age was easy to know,the age could be used to estimate the carbon storage.[Ch,12 tab.35 ref.]