Street trees are highly visible components of the urban forest, providing ecosystem services to city residents, but tree mortality can result in a loss of these essential benefits. Here, we focus on how street tree survival in Philadelphia, Pennsylvania (US) has been influenced by 1) tree traits and attributes, 2) the local biophysical environment, and 3) socioeconomic context. We used a longitudinal monitoring approach with a 6-year time interval and 103 randomly-located, fixed-length permanent plots, containing a range of tree size classes, to assess street tree survival rates, predictors of survival, and the balance of tree losses and gains. Street trees surveyed in this study experienced an annual mortality rate of 3.68% and followed a Type III mortality curve, with the highest annual mortality rates in the smallest size class. On the surveyed plots, there was a net decrease of live trees over the study period (2657 to 2542; 4.33% decline). Multivariate logistic regression revealed significant associations between street tree survival and tree crown vigor, species traits (expected mature stature and drought tolerance), site type, land use type, % impervious surface in a 15 m buffer, parcel-level demolition events, % of residents in poverty, % unoccupied households, and % renter-occupied households. Additionally, the final model included a multiplicative interaction term between crown vigor and tree size with separation in pattern of small (DBH < 7.6 cm) from larger (DBH ≥ 7.6 cm) trees. Our findings suggest that targeted management interventions may enhance overall street tree survival, such as focusing on small trees, as well as trees in sidewalk cut-outs, commercial or industrial areas, or near demolition activity. Longitudinal monitoring studies such as ours provide valuable information about how urban forest systems change over time, with assessments that are valuable for management by municipal foresters and other street tree stewards.

中文翻译：

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费城行道树生存的预测因素：树木特征、生物物理环境和社会经济背景

行道树是城市森林中引人注目的组成部分，为城市居民提供生态系统服务，但树木死亡可能会导致这些基本效益的丧失。在这里，我们重点关注美国宾夕法尼亚州费城行道树的生存如何受到 1) 树木性状和属性、2) 当地生物物理环境和 3) 社会经济背景的影响。我们采用纵向监测方法，时间间隔为 6 年，并使用 103 个随机定位、固定长度的永久地块（包含一系列树木尺寸类别）来评估行道树存活率、存活预测因子以及树木损失的平衡和收获。本研究中调查的行道树年死亡率为 3.68%，遵循 III 型死亡率曲线，最小尺寸类别的年死亡率最高。在调查的地块上，研究期间活树数量净减少（从 2657 棵减少到 2542 棵；​​减少 4.33%）。多元 Logistic 回归揭示了行道树存活率与树冠活力、物种性状（预期成熟高度和耐旱性）、场地类型、土地利用类型、15 m 缓冲区中不透水表面的百分比、地块级拆除事件的百分比之间存在显着关联贫困居民、无业家庭百分比和租房家庭百分比。此外，最终模型包括树冠活力和树木大小之间的乘法交互作用项，其中小树（DBH < 7.6 cm）与大树（DBH ≥ 7.6 cm）的模式分离。我们的研究结果表明，有针对性的管理干预措施可以提高行道树的整体存活率，例如关注小树以及人行道切口、商业或工业区或拆除活动附近的树木。像我们这样的纵向监测研究提供了有关城市森林系统如何随时间变化的宝贵信息，其评估对于市政林务员和其他街道树木管理员的管理非常有价值。