When Green Infrastructure Turns Grey: Plant Water Stress as a Consequence of Overdesign in a Tree Trench System
When Green Infrastructure Turns Grey: Plant Water Stress as a Consequence of Overdesign in a Tree Trench System
复制标题
当绿色基础设施变灰时：树沟系统过度设计造成的植物水分压力
作者：
Min;J. Caplan;S. Eisenman;B. Wadzuk
绿色基础设施（GI）系统常常被过度设计。这可能是静态尺寸调整的副产品（例如，考虑设计风暴的径流量，但不考虑渗漏率），也可能是有意为之（例如，缓冲随时间的性能损失）。在树沟和其他胃肠道系统中，雨水需要在接触种植介质之前积聚在渗透床中，过度设计可能会显着降低植物水的可用性。这项研究调查了过度设计的树沟系统的水文动力学和水关系，并确定了导致、复合和减轻植物胁迫风险的因素。渗透床中的水三年内仅到达土坑一次，该事件发生在消防栓释放期间。此外，由于土壤介质的水力特性，事件期间土坑中保留的水量极少。在整个生长季节，这两种树种中的一种经常遭受水分胁迫，而另一种则很少出现这种情况。这些截然不同的反应可能分别归因于根部主要局限于土坑和到达更深的水源。这项研究的结果表明，在渗透床中嵌入土坑的系统中，过度设计会增加水到达土壤介质所需的风暴规模，减少风暴之间的植物水可用性，并最终引发生理应激。
Green infrastructure (GI) systems are often overdesigned. This may be a byproduct of static sizing (e.g., accounting for a design storm’s runoff volume but not exfiltration rates) or may be deliberate (e.g., buffering against performance loss through time). In tree trenches and other GI systems that require stormwater to accumulate in an infiltration bed before it contacts the planting medium, overdesign could reduce plant water availability significantly. This study investigated the hydrological dynamics and water relations of an overdesigned tree trench system and identified factors contributing to, compounding, and mitigating the risk of plant stress. Water in the infiltration bed reached soil pits only once in three years, with that event occurring during a hydrant release. Moreover, minimal water was retained in soil pits during the event due to the hydraulic properties of the soil media. Through a growing season, one of the two tree types frequently experienced water stress, while the other did so only rarely. These contrasting responses can likely be attributed to roots being largely confined to the soil pits vs. reaching a deeper water source, respectively. Results of this study demonstrate that, in systems where soil pits are embedded in infiltration beds, overdesign can raise the storm size required for water to reach the soil media, reducing plant water availability between storms, and ultimately inducing physiological stress.
DOI：
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发表时间：
2015-10
期刊：
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影响因子：
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作者：
Douglas M. Bates;M. Maechler;Ben Bolker;Steven C. Walker
通讯作者：
Douglas M. Bates;M. Maechler;Ben Bolker;Steven C. Walker