Tree mortality of European beech and Norway spruce induced by 2018-2019 hot droughts in central Germany
Tree mortality of European beech and Norway spruce induced by 2018-2019 hot droughts in central Germany
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DOI：
10.1016/j.agrformet.2021.108482
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发表时间：
2021-09
影响因子：
6.2
通讯作者：
Nora Obladen;Pia Dechering;Georgios Skiadaresis;Willy Tegel;Joachim Keßler;S. Höllerl;Sven Kaps;Martin Hertel;C. Dulamsuren;T. Seifert;Mareike Hirsch;A. Seim
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文献类型：
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作者：
Nora Obladen;Pia Dechering;Georgios Skiadaresis;Willy Tegel;Joachim Keßler;S. Höllerl;Sven Kaps;Martin Hertel;C. Dulamsuren;T. Seifert;Mareike Hirsch;A. Seim
人为气候变化使全球森林生态系统超越了极限。森林普遍死亡的事件是由于日益频繁和严重的干旱造成的直接和间接影响。在这里，我们专注于一个广泛的死亡事件在挪威云杉（云杉（L.）H.喀斯特。）和欧洲山毛榉（Fagus sylvatica（L.））德国的森林，在2018 - 2019年连续的炎热干旱之后。为了检验这种死亡是否确实归因于观察到的干旱发生和强度趋势，我们在巴伐利亚州北方的三个土壤特性不同的低海拔地点（Spessart、Hassberge、Fichtelberg）对143棵山毛榉和186棵云杉进行了采样。我们分析了长期的水文气候敏感性和生长响应极端事件的五个网站和物种的特定树轮宽度年表，包括每个物种的参考网站。山毛榉的生长是敏感的干旱在4月至6月，而云杉的生长是密切相关的干旱在6月至8月，除了在稍高的海拔地区的Fichtelberg网站，在那里观察到夏季温度信号。在Spessart和Hassberge网站的树木表现出增加响应水文气候条件下，在1976年极端干旱后，从20世纪90年代起，在Fichtelberg网站4月。云杉小蠹（Ips typographusL.）2018年干旱期间的爆发加速了Spessart和Hassberge站点约50%树木的高死亡率。2018年，约7%的山毛榉树在哈斯贝格遗址死亡，这是粘土含量最高的遗址。我们的研究结果表明，这些广泛的死亡事件可以归因于干旱敏感性的增加，并加速了连续最近的干旱年。需要对这些具有生态和经济重要性的树种采取可持续森林管理做法，以减轻未来全球变暖的影响。
Anthropogenic climate change pushes forest ecosystems globally beyond their limits. Widespread events of forest die-off have been attributed to direct and indirect impacts of increasingly frequent and intense droughts. Here, we focus on an extensive mortality event in Norway spruce (Picea abies(L.) H. Karst.) and European beech (Fagus sylvatica(L.)) forests in Germany, following the successive 2018 – 2019 hot droughts. To examine whether this die-off indeed attributed to observed trends in drought occurrence and intensity, we sampled 143 beech and 186 spruce trees at three low-elevation sites (Spessart, Hassberge, Fichtelberg) with different edaphic properties in northern Bavaria. We analysed long-term hydroclimatic sensitivity and growth responses to extreme events of five site- and species-specific tree-ring width chronologies, including a reference site for each species. Growth of beech was sensitive to drought in April to June, whereas spruce growth was strongly related to drought during June to August, except at slightly higher elevations at the Fichtelberg site, where a summer temperature signal was observed. Trees at the Spessart and Hassberge sites showed an increased response to hydroclimatic conditions in April following the extreme drought in 1976 and from the 1990s onwards at the Fichtelberg site. Spruce bark beetle (Ips typographusL.) outbreaks during the 2018 drought accelerated the high mortality rates in around 50% of the trees at the Spessart and Hassberge site. In 2018, around 7% of all beech trees died at the Hassberge site, the site with the highest clay content. Our results suggest that these widespread mortality events can be attributed to an increasing drought sensitivity and were accelerated by the consecutive recent drought years. Sustainable forest management practices for these ecologically and economically important tree species are required to mitigate the effects of global warming in the future.