ABSTRACT Tree biomass models are increasingly needed for the estimation of carbon storage and for testing and parameterizing process-based growth models, but most biomass models have been estimated using data from even-aged stands. Here we took measurements from individual Norway spruce trees grown in uneven-aged stands in Southern Finland to characterize tree structure and to estimate the biomasses of tree components. Using the data, we tested various structural biomass equations developed for even-aged stands for their suitability to uneven-aged stands. The test trees had longer crowns than usually found in an even-aged Norway spruce stand, ranging from 55 to 85% of total tree height. The average proportion of total biomass in branches and foliage was 13.8 % and 7.0 %, respectively. The average wood density of the test trees was slightly higher than that reported for Norway spruce trees of comparable size. The structural relationships found in trees under even-aged management were applicable to trees growing in uneven-aged stands but required re-parameterization. In particular, the trees had higher branch and stem biomass than trees of same stem and crown dimensions on average in even-aged stands. The relationship of crown ratio and the slenderness index on an uneven-aged stands also differed from those reported in even-aged stands.

中文翻译：

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芬兰南部不均匀树龄生长的挪威云杉的生物量和结构

摘要越来越需要树木生物量模型来估计碳储存以及测试和参数化基于过程的生长模型，但大多数生物量模型是使用来自偶龄林分的数据估计的。在这里，我们对生长在芬兰南部不均匀树龄的挪威云杉树进行了测量，以表征树木结构并估计树木成分的生物量。使用这些数据，我们测试了为等龄林分开发的各种结构生物量方程，以确定它们对不等龄林分的适用性。测试树的树冠比通常在等龄挪威云杉林中发现的树冠更长，占总树高的 55% 到 85%。枝叶总生物量的平均比例分别为13.8%和7.0%。测试树木的平均木材密度略高于报告的同等大小的挪威云杉树的密度。在等龄管理下的树木中发现的结构关系适用于生长在异龄林中的树木，但需要重新参数化。特别是，在偶龄林分中，树木的枝干生物量高于相同茎和冠径的树木的平均水平。异龄林分冠比与细长指数的关系也与同龄林分报道的不同。平均而言，在等龄林分中，树木的枝干生物量高于相同茎和冠径的树木。异龄林分冠比与细长指数的关系也与同龄林分报道的不同。在等龄林分中，树木的枝干生物量高于相同茎和冠径的树木的平均水平。异龄林分冠比与细长指数的关系也与同龄林分报道的不同。