Consistent influence of tree diameter and species on damage in nine eastern North America tornado blowdowns
Consistent influence of tree diameter and species on damage in nine eastern North America tornado blowdowns
复制标题
树木直径和树种对北美东部九次龙卷风破坏的一致影响
DOI：
10.1016/j.foreco.2007.03.013
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发表时间：
2007
影响因子：
3.7
通讯作者：
C. Peterson
中科院分区：
文献类型：
--
作者：
C. Peterson
天然森林风对树木的破坏模式是可预测的吗？在这里，我综合了9个被龙卷风扰乱的北美森林遗址的已发表和未发表的发现，以询问树木的直径和物种特征如何很好地预测树木的破坏模式。作者和助手对所有地点进行了抽样，采用了大致相同的方法，从而避免了直接跨地点比较风损害的许多障碍。在几乎所有的情况下，随着树木直径的增加，树木被砍伐的风险稳步增加。在大多数地点，连根拔起比树干断裂更常见，尽管它们的相对频率随树木直径的变化而变化，并且在物种和地点之间以复杂的方式变化。即使在控制直径的情况下，物种在树木倒下的风险上也有很大的不同。然而，不同树种间的树木砍伐风险排序是一致的，这表明不同立地和不同林型间的物种差异是普遍存在的。在9个地点中，只有2个地点存在木材强度特性的显著影响，与物种身份无关。树木砍伐类型与树径的相关性较弱，但不同树种间的差异不一致。在8个地点中，有6个地点的大树比小树的砍伐方向明显更向东。在样地尺度上，林分高度和密度的变化特征与损害程度的关系并不一致。在单个树木的尺度上，基于易于记录的树径和物种特征，对树木的砍伐风险、发芽和砍伐方向存在中等水平的可预测性；在这些特征的基础上，伤害类型仍然很难预测。
Are tree damage patterns in natural-forest windthrows predictable? Here, I synthesize published and unpublished findings from nine North American forest sites that were disturbed by tornadoes, to ask how well tree damage patterns might be predicted on the basis of tree diameter and species identity. All sites were sampled by the author and assistants, using generally similar methodology, thereby avoiding many of the barriers to direct cross-site comparison of wind damage. In almost all cases, there is a consistent pattern of steady increase in risk of treefall with tree diameter. In most sites, uprooting was substantially more common than trunk breakage, although their relative frequencies varied with tree diameter, and among species and sites in complex ways. Species differed substantially in risk of treefall, even when controlling for diameter. However, ranking among species in risk of treefall was consistent, suggesting that among species differences are general across sites and forest types. In only two out of nine sites was there a significant influence of wood strength properties, independent of species identity. Type of treefall was weakly related to tree diameter, although differences among species were not consistent among sites. Direction of treefall was significantly more eastward for large compared to small trees in six out of eight sites. Stand-level characteristics of height variation, and density, were not consistently related to level of damage at the plot scale. At the scale of individual trees, a moderate level of predictability exists for treefall risk, sprouting, and direction of fall on the basis of easily recorded tree diameter and species identity; type of damage remains poorly predicted on the basis of these traits.