ON THE DETERMINATION OF QUALITY CLASS BY ‘TOP’ HEIGHT INSTEAD OF MEAN HEIGHT FOR CONIFERS IN GREAT BRITAIN
ON THE DETERMINATION OF QUALITY CLASS BY ‘TOP’ HEIGHT INSTEAD OF MEAN HEIGHT FOR CONIFERS IN GREAT BRITAIN
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DOI：
10.1093/forestry/18.1.28
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发表时间：
1944
期刊：
影响因子：
2.8
通讯作者：
A. Foggie
中科院分区：
文献类型：
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作者：
A. Foggie
讨论了林业委员会产量表中采用平均高度或平均作物高度作为质量等级指标的问题。定义并讨论了美国使用的优势高度和印度使用的顶高作为质量指标。本文描述了平均年龄人工林作物顶高与平均高度的相关性，并给出了欧洲落叶松、苏格兰松和挪威云杉的回归曲线和统计数据。给出了欧洲落叶松平均高度和顶高的比较曲线，以及委员会所有品种产量表中按年龄划分的顶高表。从这项研究看来，对于所处理的物种（苏格兰和科西嘉松，欧洲和日本落叶松，挪威和锡特卡云杉，以及道格拉斯冷杉），平均作物高度是一个可接受的场地质量指标。不过，是顶高。具有测定和在混合作物中使用更简单的优点。关键词:
Mean height or mean crop height as used as the quality class index in the Forestry Commission yield tables is discussed. Dominant height as used in America and top height as used in India as alternative quality indices, are defined and discussed. The investigation of the correlation between top height and mean height in even-aged plantation crops is described, and the resulting regression lines and statistics for European Larch, Scots Pine, and Norway Spruce are given. Comparative curves for mean height and top height of European Larch and tables of top height by age for the quality classes of the Commission's yield tables for all species are given. From this study it appears that for the species dealt with (Scots and Corsican Pine, European and Japanese Larch, Norway and Sitka Spruce, and Douglas Fir mean crop height is an acceptable index of site quality. Top height, however. has the advantage of greater simplicity in its determination and in use in mixed crops. KEYWORDS: