THE EXTENT OF OLD-GROWTH THUJA-OCCIDENTALIS ON CLIFFS OF THE NIAGARA ESCARPMENT
THE EXTENT OF OLD-GROWTH THUJA-OCCIDENTALIS ON CLIFFS OF THE NIAGARA ESCARPMENT
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DOI：
10.1139/b91-206
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发表时间：
1991-07-01
期刊：
影响因子：
--
通讯作者：
KELLY, PE
中科院分区：
文献类型：
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作者：
LARSON, DW;KELLY, PE
对生长在加拿大安大略南部尼亚加拉悬崖垂直悬崖上的崖柏种群进行了广泛的随机抽样，以确定最近描述的古老森林的范围。 9个站点分布沿着长度的悬崖进行了集中采样，并从这些，1254增量芯或横截面，从872个树木在所有年龄组。 结果表明，所有的悬崖支持一个大致相似的古老的森林发育不良的树木，但统计上显着差异被发现在网站之间的树木数量。 树木的高度和直径在不同地点之间没有很大的差异。 最大年龄为532岁（抽样）和814岁（估计）在随机普查中发现，虽然在随后的选择性抽样，完整的茎长达1032年被发现。火灾和人为切割的发生率也被测量，但几乎没有发现这种干扰的证据。得出的结论是，尼亚加拉悬崖的暴露悬崖面支持最古老，最广泛，也是北美东部迄今为止最完整的原始森林生态系统。 研究基本森林生态学、特别是树木年代学的机会相当大。
Extensive random sampling of populations of Thuja occidentalis growing on vertical cliffs of the Niagara Escarpment in southern Ontario, Canada, was conducted to determine the extent of an old-growth forest that had recently been described. Nine sites distributed along the length of the escarpment were intensively sampled and from these, 1254 increment cores or cross sections were obtained from 872 trees in all age categories. The results show that all cliffs support a broadly similar old-growth forest of stunted trees, but that statistically significant differences were found in the numbers of trees among sites. No large differences among sites were found in heights or diameters of trees. Maximum ages of 532 (sampled) and 814 years (estimated) were found in the random census, although in subsequent selective sampling, intact stems up to 1032 years were found. The incidence of fire and cutting by humans was also measured, but little evidence of such disturbances was found. It is concluded that exposed cliff faces of the Niagara Escarpment support one of the oldest, most extensive, and most intact old-growth forest ecosystems yet described for eastern North America. The opportunities for the study of basic forest ecology and especially for dendrochronology are considerable.