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通过对水曲柳(Fraxinus mandshurica)天然次生林的生物量和热值的测定,研究了其能量结构。结果如下:(1)水曲柳天然次生林乔木层平均热值最高,为17.9704KJ/g;下木层居中,为17.4422KJ/g;草本层最低,为16.5216KJ/g。乔木层中木质器官(干材、干皮、枝、根)热值大于叶的热值,而各木质器官之间差异不大。(2)林龄为43a的水曲柳天然次生林,乔木层能量现存量为31.59×10~8KJ/ha,其中干材能量现存量占比例最大,叶最低。(3)林龄为43a的水曲柳天然次生林能量净初级平均生长量为96.57×10~6KJ/ha·a,近5a能量净初级平均生长量为170.25×10~6KJ/ha·a。平均光能利用率为0.42％,近5a平均光能利用率为5.74％。净初级生产力和光能利用率都随林龄增大而增加。
Through measuring the biomass and calorific value of the natural secondary forest of Fraxinus mandshurica, the energy structure of the secondary forest was studied. The results are as follows: (1) The average calorific value of natural tree layer in Fraxinus mandshurica was the highest (17.9704KJ / g), that in the middle layer was 17.4422KJ / g, and that in the herb layer was the lowest (16.5216KJ / g). The caloric value of the woody organs (dry matter, dry skin, branches and roots) in the arbor layer is greater than the caloric value of the leaf, with little difference between the woody organs. (2) The natural secondary forest of Fraxinus mandshurica, whose age was 43a, had an energy content of 31.59 × 10 ~ 8KJ / ha, in which the energy stock of dry material accounted for the largest proportion and the leaf was the lowest. (3) The net average primary net growth of natural secondary forests with the age of 43 years was 96.57 × 10 ~ 6KJ / ha · a, and the net primary average growth of near-5a energy was 170.25 × 10 ~ 6KJ / ha · a. The average utilization rate of light energy was 0.42%, and the average utilization rate of light energy in the past 5 years was 5.74%. Net primary productivity and solar energy utilization increased with age.