长沙城市森林生物量的结构特征

Pattern characteristics of stand biomass of urban forest in Changsha city

采用现场实测的方法,对长沙城市樟树马尾松林生物量的结构特征和生产力进行了研究。结果表明,林分组成的乔木树种单株生物量不等同,其中樟树单株生物量为191.12 kg、马尾松291.97 kg、山矾29.37 kg、对萼山矾18.04 kg;林分乔木层生物量为76.14 t.hm-2,组成树种樟树为28.67 t.hm-2,占乔木层总生物量37.7%;马尾松17.51 t.hm-2,占23.0%;山矾22.91 t.hm-2,占30.0%;对萼山矾7.05 t.hm-2,占9.3%;林下灌木层生物量为16.15 t.hm-2,草本层为0.22 t.hm-2,层外层为0.05 t.hm-2;林地死地被物生物量为5.00 t.hm-2,其中L层为0.53 t.hm-2、F层2.57 t.hm-2、H层1.97 t.hm-2;凋落物生物量为7601.66 kg.hm-2,其中凋落针叶量占43.10%、凋落阔叶量占29.55%、落果6.47%、有机碎屑20.88%,并具有明显的季节性凋落变化节律,年凋落物量有60%以上发生在秋冬季节;林分生产力4.85 t.hm-2.a-1,其中樟树为2.62 t.hm-2.a-1、马尾松为0.73 t.hm-2.a-1、山矾为1.14 t.hm-2.a-1、对萼山矾0.36 t.hm-2.a-1。研究结果可为城市森林生态系统结构和功能研究提供基本数据,为评价城市森林的服务功能和可持续经营提供科学依据。

Pattern characteristics of stand biomass and productivity in Cinnamomum camphora（L.） Presl and Pinus massoniana Lamb mix-forest ecosystems were investigated in Changsha city,Hunan province.The results show that mean biomass of an individual tree was 191.12,291.97,29.37,and 18.04 kg in the four tree species,C.camphora,P.massoniana,Symplocos sumuntia and Symplocos anomala in the studied mix-forests.Stand biomass of overstorey in the forests was 76.14 t·hm-2,of which C.camphora tree was 28.67 t·hm-2,accounting for 37.7%;P.massoniana was 17.51 t·hm-2,accounting for 23.0%;Symplocos sumuntia was 22.91 t·hm-2,accounting for 30.0%,and Symplocos anomala was 7.05 t·hm-2,accounting for 9.3% of the total biomass in overstorey.Biomass in shrub layer,herbivorous layer and lianas layer was 16.15,0.22 and 0.05 t·hm-2 respectively.Biomass in dead floor layer was 5.00 t·hm-2,of which non-decomposed part（L layer） was 0.53 t·hm-2,semi-decomposed part（F layer） was 2.57 t·hm-2 and decomposed part（H layer） was 1.97 t·hm-2.Annual amount of litter-fall in the forests was 7 601.66 kg·hm-2,of which litter-needle,litter-broad-leaves,litter fruit and litterorganic debris accounted for 43.10%,29.55%,6.47% and 20.88% respectively.And its seasonal changes were obvious.More than 60% of annual amount of litter-fall took place in the autumn and winter seasons.Stand productivity in overstorey in the mix-forests was 4.85 t·hm-2a-1,of which Camphor tree was 2.62 t·hm-2a-1,Masson pine 0.73 t·hm-2a-1,Symplocos sumuntia 1.14 t·hm-2a-1 and Symplocos anomala 0.36 t·hm-2a-1.The results provide basic data for the research on structure and function of urban forest ecosystem,and also provide scientific references for the evaluation of urban forest service function and sustainable management.