巴山松天然林生物量和生产力的研究

 经测定分析陕西南部28—37年生巴山松天然林的生物量和净初级生产量，结果表明，林分乔木层生物量为81.28t／ha，草本下木生物量为1.45t／ha，林分凋落物量为11.16t／ha;乔木层净初级生产量为6.94t／ha·yr，约45%分配到树叶。巴山松林的消光系数平均为0.33。在地上部生产结构方面，枝重主要集中在树冠中、下部，叶龄愈大，叶重在树冠下部的比例愈高。巴山松林木的根系总长度约99.4km／ha，其中细根占58%。

BIOMASS AND PRODUCTIVITY BY NATURAL PINUS HENRYT FORESTS

The biomass and net primary production of 28—37 year-old natural Pinus henryi forests were investigated and analyzed. The results showed that, the biomass of arbor layer, undergrowth (including herb) layer together with the dead materials were 81.28 t/ha, 1.45 t/ ha and 11.16t/ha respectively. The net primary production of arbor layer was 6.94t/ha·a, of which leaf accounted for about 45%, extinction coefficient of the forest had a average of 0.33. The biomass and net primary production of the stands were closely proportional to LAI. Regarding the aboveground production structure, the branch weight was mainly distributed in the mid-lower part of the crown, and leaf weight percentage increased in the lower part of the crown with needle age. The length of root system for P. henryi forests was about 99.4km/ha, of which fine roots accounted for 58% of the total.