Using dendrochronology to identify major ice storm events in oak forests of southwestern Virginia
Using dendrochronology to identify major ice storm events in oak forests of southwestern Virginia
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DOI：
10.3354/cr020041
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发表时间：
2002-02
期刊：
影响因子：
1.1
通讯作者：
C. Lafon;J. Speer
中科院分区：
文献类型：
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作者：
C. Lafon;J. Speer
大冰暴是北美东部重要的森林干扰因子和自然灾害.森林破坏的研究表明，冰暴的严重程度因地形位置而异，但可用于评估冰暴气候学中细尺度变化的气候信息很少。我们的研究评估了树木年轮分析的实用性，以确定精细尺度的空间格局和长期的时间变化的主要冰暴的频率。我们在栗栎栎的年轮年表中寻找冰暴信号。和黑橡木Q.绒毛草在弗吉尼亚州西南部的两个地点，在1979年和1994年受到已知的冰暴影响。这些物种的径向生长表现出双重响应冰暴干扰。在冰风暴之后的几年里，冠层大量减少的树木表现出径向生长减少。其他的树木由于失去了竞争对手而表现出更大的增长。我们确定了阈值的环宽度增加和减少，区分冰暴从其他事件，允许初步尝试重建冰暴的历史，在每个2个研究地点。对于我们的Gap Mountain站点，跨越1914-1998年期间的环宽年表记录了1920年、1979年和1994年主要冰暴的明显信号。对于步行者山网站，我们的研究结果表明，在1901年至1998年期间的立场受到重大冰风暴在1918年和1994年。这项研究表明，dendrochronology提供了一个很有前途的方法，了解细尺度的空间格局的冰暴干扰阔叶林。
Major ice storms are significant forest disturbance agents and natural hazards in east- ern North America. Studies of forest damage suggest that ice storm severity varies among topo- graphic positions, but little climatic information is available to evaluate fine-scale variations in ice storm climatology. Our study assesses the utility of tree-ring analysis for identifying fine-scale spatial patterns and long-term temporal variations in the frequency of major ice storms. We looked for ice storm signals in tree-ring chronologies of chestnut oak Quercus prinus L. and black oak Q. velutina Lam. at 2 sites in southwestern Virginia that were affected by known ice storms in 1979 and 1994. Radial growth of these species exhibits a dual response to ice storm disturbance. Trees with substan- tial canopy loss show reduced radial growth for several years following an ice storm. Other trees dis- play increased growth due to the loss of competitors. We identified thresholds of ring-width increase and decrease that distinguished ice storms from other events, permitting a preliminary attempt to reconstruct ice storm history at each of the 2 study sites. For our Gap Mountain site, ring-width chronologies spanning the period 1914-1998 record apparent signals of major ice storms in 1920, 1979, and 1994. For the Walker Mountain site, our results suggest that during the period 1901-1998 the stand was affected by major ice storms in 1918 and 1994. This study suggests that den- drochronology provides a promising method for understanding fine-scale spatial patterns of ice storm disturbance in hardwood forests.