Abstract The reiteration process involves the replication of large and complex modules of a tree structure. Reiteration may occur in sequential (i.e. normal) tree development but may also appear on old structures in response to a traumatic event (delayed traumatic reiterations, DTR), stress or internal constraints. This process is of prime interest in the context of managing trees located under electrical networks as DTR are the tree parts that will repeatedly be trimmed because of their interaction with electric wires. However, the determinants of DTR growth are still largely unknown. In order to identify the most important DTR growth determinants and their scale of action, we measured 1061 DTR in 285 trees of six species located in 11 cities in the province of Quebec, Canada, along a large climatic gradient. Nine explicative variables, four at the local scale (dealing with within crown light and water supply), three at the tree scale (ontogeny, urban surrounding environment and crown shape), and two at the geographic scale (regional temperature and precipitation), were used to explain DTR growth. Boosted regression trees were used to fit the complex response of DTR length to each individual variable and to quantify the influence of each variable and the influence of the three scales. Results enabled us to link the response of DTR growth to physiological processes and provide evidence of a mostly local control of DTR growth potentially influenced by a combination of water supply, light availability, and C reserves. Tree size had a relatively strong influence, while the urban environment and maintenance conditions had only a weak effect. Although the regional climatic conditions were found to affect DTR growth, their effects varied greatly among species. Based on our results, we provide some recommendations for the management and modeling of urban trees, and draw insight for future research.

中文翻译：

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延迟创伤性树木重复生长的决定因素：树枝生长控制水平以及对城市树木管理、建模和未来研究的见解

摘要 迭代过程涉及树结构的大型复杂模块的复制。重复可能发生在顺序（即正常）树发展中，但也可能出现在旧结构上以应对创伤事件（延迟创伤重复，DTR）、压力或内部约束。这个过程在管理位于电网下的树木的背景下是最重要的，因为 DTR 是树木部分，由于它们与电线的相互作用而将反复修剪。然而，DTR 增长的决定因素在很大程度上仍是未知的。为了确定最重要的 DTR 生长决定因素及其作用范围，我们测量了位于加拿大魁北克省 11 个城市的 6 种树种的 285 棵树的 1061 DTR，沿着大气候梯度。九个解释性变量，四个局部尺度（处理树冠内光照和供水），三个树尺度（个体发育、城市周边环境和树冠形状）和两个地理尺度（区域温度和降水），用于解释 DTR生长。Boosted 回归树用于拟合 DTR 长度对每个单独变量的复杂响应，并量化每个变量的影响和三个尺度的影响。结果使我们能够将 DTR 生长的反应与生理过程联系起来，并提供证据表明 DTR 生长的主要局部控制可能受供水、光照和 C 储备的组合影响。树木大小的影响相对较大，而城市环境和维护条件的影响较小。尽管发现区域气候条件会影响 DTR 的生长，但它们的影响因物种而异。基于我们的研究结果，我们为城市树木的管理和建模提供了一些建议，并为未来的研究提供了见解。