岩溶石漠化山地林分生物量分布规律和生产力特征研究

Biomass distribution rule and productivity character of forest stand in Karst desertification area

为探明岩溶石漠化山地生态重建后的植被生产力特征,对桂北地区岩溶石漠化山地12年生的林分进行野外实地观测,采用分层切割法对主要造林树种的生物量空间分布格局进行研究。结果表明:6个主要造林树种在岩溶石漠化山地上均能表现出良好的生长状态,在6种绿化树种中,刺槐的各项生长指标都表现出最好的生长效果,胸径和树高年平均生长量分别达到0.65 cm和0.58 m;其次是乡土树种女贞,胸径和树高年平均生长量分别为0.63 cm和0.43 m;4个乔木树种干的生物量比例分别是刺槐(78%)、女贞(45%)、臭椿(67%)、榆树(45%),刺槐和臭椿的主干非常明显,而分枝很少;4种乔木的枝叶指数大小依次是榆树(0.41)、女贞(0.40)、臭椿(0.26)、刺槐(0.15),说明榆树和女贞具有较大的生产潜力,可以充分利用光能生产干物质;6种绿化树种的冠根比分别为刺槐(2.24)、女贞(2.64)、臭椿(3.88)、榆树(2.76)、冬青(1.39)、酸枣(4.56),表明酸枣对岩溶石漠化山地的适应性最强,而冬青最弱;单株生物量最大的是刺槐,为21.61 kg/株,其次分别为女贞、臭椿、榆树、冬青和酸枣,酸枣的生物量相对较小、仅为2.89 kg/株;6种不同林分单位面积生物量的大小为女贞>刺槐>榆树>臭椿>冬青>酸枣,相对于其他4个树种,刺槐与女贞林分表现出了很好的优势,单位面积生物量分别达了42 139 kg/hm2和50 522 kg/hm2。

In order to carry out productivity character of vegetation in karst area after ecological restoration, after field investigation of 12 age forest stand of karst area of north Guilin, biomass spatial distribution was studied by layer cutting method. Results showed that： 6 main trees could grow well in coal waste pile, and Robinia pseudoacacia L. had best growth index, the average DBH and height growth were 0.65 cm and 0.58 m, then it was Ligusrtum lucidum Ait, the average DBH and height growth were 0.63 cm and 0.43 m; Trunk biomass proportion of 4 arbors were Robinia pseudoacacia L.（78%）, Ligusrtum lucidum Ait.（45）, Ailanthus altissima Swingle （67%）, Ulmus pumila L.（45%）, Robinia pseudoocacia L. and Ailanthus altissima Swingle had obvious trunk and less branch; Branch and leaf index of 4 arbors were Ulmus pumila L.（0.41）, Ligusrtum lucidum Air.（0.40）, Ailanthus oltissima Swingle（0.26）, Robinia pseudoacacia L.（0.15）, Ulmus pumila L. and Ligusrtum lucidum Ait. had bigger potential productivity to utilization of light; Crown and root rate of 6 trees were Robinia pseudoacacia L.（2.24）, Ligusrtum lucidum Air.（2.64）, Ailanthus altissima Swingle（3.88）, Ulmus pumila L.（2.76）, Ilex purpurea Hassk.（1.39）, Ziziphus jujuba var.spinosa （Bunge）Hu （4.56）, which showed that Ziziphus jujuba var.spinosa （Bunge）Hu had best adjustable capability; Robinia pseudoacacia L. had largest individual biomass of 21.61 kg/tree, then it followed Ligusrtum lucidum Ait., Ailanthus dtissima Swingle, Ulmus pumila L., Ilex purpurea Hassk. and Ziziphus jujuba var.spinosa （Bunge）Hu,the smallest individual biomass was Ziziphus jujuba var.spinosa （Bunge）Hu of 2.89 kg/tree; Forest stand biomass of 6 trees were： Ligusrtum lucidum Ait.〉Robinia pseudoacacia L.〉llex purpurea Hassk.〉Ailanthus altissima Swingle〉Ulmus pumila L.〉Ziziphus jujuba var.spinosa （Bunge）Hu, Robinia pseudoacacia L. and Ligusrtum lucidum Ait. biomass reached to 42 139 kg/hm^2 and 50 522 kg/hm^2.