College of Forestry, Hebei Agricultural University, 071001 Baoding, China.
College of Landscape Architecture and Tourism, Hebei Agricultural University, 071001 Baoding, China.
Sci Total Environ. 2024 Aug 15;938:173521. doi: 10.1016/j.scitotenv.2024.173521. Epub 2024 May 25.
Forests are experiencing increasingly severe drought stress worldwide. Although most studies have quantified how tree growth was affected by extreme droughts, how trees recover from different drought intensities are still poorly understood for different species. We used a network of tree-ring data comprising 731 Quercus mongolica trees across 29 sites, 312 Larix olgensis Henry trees from 13 sites, and 818 Larix principis-rupprechtii trees from 34 sites, covering most of their distribution range in northern China, to compare the influences of drought intensity on post-drought recovery. The results showed that summer droughts had strong negative influences on tree growth. Post-drought growth varied with drought intensity for the three species. Larix species exhibited strong legacy effects after severe droughts, which is related to the lack of compensatory growth. In contrast, the compensatory growth of Q. mongolica reduced drought legacy effect. However, the compensatory growth of Q. mongolica gradually weaken with increasing drought intensity and disappeared during severe drought. Our findings indicated that influence of drought on Q. mongolica growth mainly shown in drought years, but Larix species suffered from long-term drought legacy effects, implying Q. mongolica rapidly recovered from droughts but Larix species need several years to recover from droughts, thus the two genera have different recovery strategy.
森林在全球范围内正经历着日益严重的干旱胁迫。尽管大多数研究已经量化了树木生长受极端干旱的影响，但对于不同物种，树木从不同干旱强度中恢复的方式仍知之甚少。我们使用了一个由 731 棵蒙古栎和 312 棵青海云杉及 818 棵华北落叶松组成的树木年轮数据集网络，这些树木分布在中国北方的 29 个地点、13 个地点和 34 个地点，以比较干旱强度对旱后恢复的影响。结果表明，夏季干旱对树木生长有很强的负面影响。对于这三个物种，旱后生长随干旱强度而变化。青海云杉和华北落叶松在遭受严重干旱后表现出强烈的滞后效应，这与缺乏补偿性生长有关。相比之下，蒙古栎的补偿性生长降低了干旱的滞后效应。然而，蒙古栎的补偿性生长随着干旱强度的增加而逐渐减弱，在严重干旱期间消失。我们的研究结果表明，干旱对蒙古栎生长的影响主要表现在干旱年份，但云杉属树种受到长期干旱滞后效应的影响，这意味着蒙古栎能迅速从干旱中恢复，但云杉属树种需要几年时间才能从干旱中恢复，因此这两个属具有不同的恢复策略。
