Abstract

One of the possible consequences of climate change is a change in the demographic dynamics of phyllophagous insects. For a retrospective analysis of this dynamics, tree rings are used, especially in regions with limited documentary data. Due to the complex nature of the factors determining tree growth, in order to more clearly identify pest-induced defoliation in tree-ring chronologies one suppress the climatic signal expressed directly or indirectly (through chronologies of non-host tree species). However, in South Siberia, the choice of non-host species is hampered by the wide distribution of polyphages, like the gypsy moth (Lymantria dispar Linnaeus) and the Siberian silk moth (Dendrolimus sibiricus Tsch.). Therefore, the analysis of pest outbreaks in larch forests of the Republic of Tuva low mountains was started by removing the climatic response based on instrumental data, identifying depressions in the residual time-series of individual tree radial growth at several sites, and comparing them with available actual data on forest damage by phyllofages. Dendroclimatic analysis showed that the model including the precipitation-to-maximum-temperature ratio for June-September of the previous season and June of the current year, i.e. the degree of aridity during the previous and current growing season, describes 43.7% of the regional variation in the growth of Siberian larch (Larix sibirica Ledeb.). After removal of this component, several periods of larch growth depression were revealed during confirmed outbreaks of the Siberian silk moth, gypsy moth, and larch tortrix (Zeiraphera diniana Gn.). The use of documented data over 1998–2016 allowed to clarify the threshold values of the portion of affected trees for intensities of the growth depression ranging 1–1.5 standard deviations, providing the required reliability of the outbreak reconstruction. The dependence of the spatio-temporal patterns of growth depression on the pest species was revealed, reflecting their migration in the affected area. It has been shown that growth depressions may be delayed compared with the actual damage by pests due to the long recovery after recurrent defoliation.

中文翻译：

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蒂瓦共和国森林草原地区落叶松径向生长对噬菌体暴发的树状年代学指示。

摘要

气候变化的可能后果之一是食叶昆虫的人口动态变化。为了对这种动态进行回顾性分析，使用了树木年轮，尤其是在文献数据有限的地区。由于决定树木生长的因素的复杂性质，为了更清楚地识别树木年轮年代中由害虫引起的落叶，人们可以直接或间接地（通过非寄主树种的年代）抑制气候信号。但是，在南西伯利亚，非寄主物种的选择因吉卜赛蛾（Lymantria dispar Linnaeus）和西伯利亚蚕蛾（Dendrolimus sibiricus）的广泛分布而受到阻碍。Tsch。）。因此，开始分析图瓦共和国低山区落叶松森林的害虫暴发是通过根据仪器数据消除气候响应，确定几个地点单个树木径向生长的残留时间序列中的凹陷并将它们进行比较来开始的。可获得的有关由叶栅造成的森林破坏的实际数据。树枝状气候分析表明，该模型包括前一个季节的6月至9月以及当年6月的降水与最高温度之比，即前一个和当前生长季节的干旱程度，描述了该地区的43.7％。西伯利亚落叶松（Larix sibiricaLedeb。）。除去该成分后，在确认的西伯利亚蚕蛾，吉普赛蛾和落叶松龟（Zeiraphera diniana Gn。）爆发期间，发现了几个落叶松生长抑制期。使用1998-2016年期间的成文数据可以阐明受影响树木部分的阈值，其生长抑制强度在1-1.5标准偏差范围内，从而提供爆发重建所需的可靠性。揭示了生长抑制的时空模式对有害生物种类的依赖性，反映了它们在受影响地区的迁移。已经表明，由于反复落叶后恢复时间长，与有害生物的实际损害相比，生长抑制可能会延迟。