Abstract Climate change is affecting tree growth and vitality, including potentially accelerating growth rate or exacerbating drought stress. Physiological and phenological changes of a tree may eventually disrupt the beneficial effects that it provides to the ecosystem (‘ecosystem services’). This research examined how the urban forest in Canberra has responded to climate change in the last 20 years. A road survey was conducted to document the growth of commonly planted trees across the city, which was then compared with a tree growth model (DISMUT) that reflected growth around the turn of the 20th century. The results suggest that urban trees have various mechanisms whereby they respond to climate change, and these mechanisms are partially based on tolerance to heat and drought, leaf phenology and age. In general, trees with high tolerance, evergreen leaves and young age grow faster and bigger than expected, while drought-intolerant, deciduous and older trees are more likely to exhibit restricted size. Water deficit is one of the main threats to tree vitality in Canberra. Species alleviate water deficit stress by forming dead branches or showing crown dieback. However, these symptoms undermine the ecosystem services that urban trees can provide. Urban forest management should be modified to adapt to the changes in trees, including accelerated growth and severe stress symptoms. DISMUT models can be updated to incorporate the systematic deviations in growth to improve predictions and scenario planning.

中文翻译：

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城市森林对气候变化的响应：堪培拉的案例研究

摘要 气候变化正在影响树木的生长和活力，包括可能加速生长速度或加剧干旱压力。树木的生理和物候变化最终可能会破坏它为生态系统提供的有益影响（“生态系统服务”）。这项研究调查了堪培拉的城市森林在过去 20 年中如何应对气候变化。进行了一项道路调查以记录整个城市常见树木的生长情况，然后将其与反映 20 世纪之交生长情况的树木生长模型 (DISMUT) 进行比较。结果表明，城市树木具有多种响应气候变化的机制，这些机制部分基于对高温和干旱的耐受性、叶片物候和年龄。一般来说，耐受性高的树木，常绿树叶和幼龄树长得比预期更快、更大，而不耐旱、落叶和老树更可能表现出尺寸受限的情况。缺水是堪培拉树木活力的主要威胁之一。物种通过形成枯枝或显示冠枯死来缓解缺水压力。然而，这些症状破坏了城市树木可以提供的生态系统服务。应调整城市森林管理以适应树木的变化，包括加速生长和严重的压力症状。可以更新 DISMUT 模型以纳入增长中的系统偏差，以改进预测和情景规划。缺水是堪培拉树木活力的主要威胁之一。物种通过形成枯枝或显示冠枯死来缓解缺水压力。然而，这些症状破坏了城市树木可以提供的生态系统服务。应调整城市森林管理以适应树木的变化，包括加速生长和严重的压力症状。可以更新 DISMUT 模型以纳入增长中的系统偏差，以改进预测和情景规划。缺水是堪培拉树木活力的主要威胁之一。物种通过形成枯枝或显示冠枯死来缓解缺水压力。然而，这些症状破坏了城市树木可以提供的生态系统服务。应调整城市森林管理以适应树木的变化，包括加速生长和严重的压力症状。可以更新 DISMUT 模型以纳入增长中的系统偏差，以改进预测和情景规划。包括加速生长和严重的压力症状。可以更新 DISMUT 模型以纳入增长中的系统偏差，以改进预测和情景规划。包括加速生长和严重的压力症状。可以更新 DISMUT 模型以纳入增长中的系统偏差，以改进预测和情景规划。