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对‘新温185号’疏散分层形树形冠层内光分布的研究,旨在深入全面地认识核桃树冠冠层内透光率(Tr)和叶面积指数(LAI)的相关关系。采用美国Li-COR公司所生产的LAI-2000冠层分析仪在日出之前和日落之后,测定分割后的小立方体内树冠的叶面积指数(LAI)和透光率(Tr)。实验样株冠层内透光率随时节变化的垂直分布是中层>上层>下层,且3层之间的变化幅度也比较接近;水平分布是外部>中部>内膛,且内膛和中部的差别性很小。冠层内的消光系数随着时期的变化呈现出从无叶期到脂化期一直保持增大的趋势。展叶期到速生生长期和速生生长期到脂化期这2个样株生长阶段消光系数出现了增长幅度很大的变化,展叶期到脂化期是消光系数变化最大的阶段。通过叶面积指数的测定可以得出关于核桃冠层内的透光率,进而可以得到冠层消光系数,展叶期到脂化期也是种植者需要多加重视的阶段。
The study on the light distribution in the canopy of canopy tree in ’Xinwen 185’ is aimed to deeply and comprehensively understand the relationship between the light transmittance (Tr) and the leaf area index (LAI) in the canopy of walnut. The leaf area index (LAI) and light transmittance (Tr) of the canopy in the divided cubes were measured before sunrise and after sunset using the LAI-2000 canopy analyzer manufactured by Li-COR, USA. The vertical distribution of the light transmittance in the canopy of the experimental samples with time change is middle layer> upper layer> lower layer, and the change range of the three layers is also close; the horizontal distribution is the outer> middle> middle, and the inner and middle Difference is small. The extinction coefficient in the canopy shows a tendency of increasing from the leafless to the lipidated stage with the change of time. The extinction coefficient at the growth stage of fast-growing stage and fast-growing stage to fattening stage showed a great change in the leaf growth stage, and the change of extinction coefficient in the leaf-setting stage to the fattening stage was the largest. Through the determination of leaf area index can be obtained about the light transmittance within the walnut canopy, and then get the canopy extinction coefficient, leaf stage to the fattening period is also a grower need to pay more attention to the stage.