四川桤柏混交林生物量的研究

 对四川省盐亭县桤柏混交林单株干重、平均净生产量、林分生物量和生产力动态的系统研究表明：桤木和柏木不同器官生物量随年龄积累变异显著，积累最多的是树干，其它器官积累较少。桤木各器官平均净生产量在2～12年上升，在12～14年左右达到峰值，随后下降，其生物量结构和垂直分布也程相同的趋势，表明桤木在16年以后已成熟，主伐年龄可定在18～20年间。柏木叶积累量的增长在幼龄期有“超前现象”。其各器官平均净生产量在2～18年内增长呈“J”型曲线．生物量结构和垂直分布仍处于剧烈分化期。在我国人工混交林中，桤柏混交林的生物量和生产力都比较高。

A STUDY ON THE BIOMASS OF ALDER AND CYPRESS ARTIFICIAL MIXEDFOREST IN SICHUAN

A systematic study on dynamics of individual dry weight increment, net mean productivity, stand biomass and primary productivity of alder and cypress artificial mixed forest has been carried out in Yaming county, Sichuan province. The study on the biomass of stands at different ages shows that the biomass accumulation of different organisms at stand age and the proportion of trunk increased while those of leaf, branch and root system weight decreased.The average net productivity of alder tree increased from 2 and 12 years old and reached the peak in the period between the 12th to 14th year and then decreased gradually after the 16th year. The same tendency was presented in the alder biomass structure and in its vertical distribution. These indicate that the quantitative maturity of alder occurred as it was 18 years old in the mixed forests.The accumulation of cypress leaf showed a so-called "advanced phenomenon". The net primary productivity of the cypress trees fitted "J" type of curve. The biomass structure and its vertical distribution were still in the state of dramatic differentiation in the duration between the 2nd and 18th year ofplant growth. Among a few types of subtropical artificial forests, the biomass and net primary productivity of the alder and cypress mixed forest is the relatively high. Therefore, this kind of artificial forest may have integrated ecological and economic benefits.