黔南珠防工程马尾松幼林生物量及生产力研究

摘要

In order to know the growth model of P. massoniana and its stand net productivity, the stand biomass and productivity of young P. massoniana forests of Pearl River Shelterbelt Construction Project in Qiannan Prefecture were studied by the methods of field survey, which would provide a theoretical basis for the planning, implementation, configuration, structural adjustment and the operation of the protection forest and management of P. massoniana forests in Qiannan Prefecture. The results showed that: 1) The stand biomass was 16. 58 t/hm2 and the biomass distribution for each layer respectively were the tree layer (66. 59%) > herb layer (19. 36%) > shrub layer (9. 35%) > litter layer (4. 70%) t Biomass of tree layer was 11. 04 t/hm2, The percentages of each organ biomass was trunk (55. 38%)> leaf(16. 44%) >branch (14.35%) >root (13.96%). 2) The stand average net productivity was 7. 44 t/( hm2 · a ) and the average net productivity of each layer was: the tree layer [3. 45 t/(hm2 · a)] > herb layer C3. 21 t/(hm2 · a): > shrub layer [0. 78 t/(hm2 · a)]. The tree layer stand biomass and net productivity increased with the aging of the stand. And the growth rate would be obviously faster five years later, featured by the year after year productivity would be greater than the average net productivity. This indicted that this stand would enter the growth of fast-growing period five years later. During this period, the management and protection methods of tending thinning, fertilization, and adjusting the structure of the stand could promote the growth of the stand and improve the stand productivity and the ecological effect of the community stand.%为了探明单株马尾松生物量的生长模型及其林分的净生产力,为马尾松珠防林的规划、实施,珠防林配置、结构调整以及全省防护林的经营、管理提供理论依据,采用实地调查的方法,对黔南珠防工程马尾松幼林生物量及林分生产力进行了研究.结果表明:1)该区马尾松幼林林分生物量为16.58 t/hm2,各层次的生物量分配依次为乔木层(66.59％)＞草本层(19.36％)＞灌木层(9.35％)＞枯落物层(4.70％)；乔木层的生物量为11.04 t/hm2,各器官所占比例为树干(55.38％)＞树叶(16.44％)＞树枝(14.35％)＞树根(13.96％).2)该区马尾松幼林林分平均净生产力为7.44t/(hm2·a),各层次的平均净生产力依次为乔木层[3.45t/(hrn2·a)＞草本层[3.21t/(hm2·a)]＞灌木层[0.78t/(hm2·a)].林分乔木层生物量和净生产力均随着林龄的增加而增加,且在5 a后增长速率明显加快,表现为连年净生产力大于平均净生产力,说明,该林分在5 a后将进入生长的速生期,此期间对其施行抚育间伐、施肥、调整林分结构等管护措施,可促进林分生长,提高林分生产力和群落整体生态效应.