Forecasting Tree Root Architecture as a Complement to Proactive Urban Green Space Design

Abstract

Abstract Background Stewarding newly planted urban trees to maturity involves consideration of above- and belowground factors. While landscape architects and urban planners often focus on aboveground tree aspects, understanding root structure and function is crucial, especially in urban areas with limited underground space and diverse soil conditions. To address the importance and challenges of belowground planning for urban tree roots, we propose a protocol for site assessment and demonstrate root growth forecasting as a complement to existing urban planning approaches. Methods This paper describes adaptations to a plant root architecture simulator, RootBox, and its subsequent application in 4 scenarios created to assess its efficacy as a complement to the phase of urban planning that prescribes vegetation type and planting location in the context of a myriad of other site considerations. RootBox was parameterized based on observed conformity of root growth simulations to generalized tree root architecture reported in the literature. Results Root growth forecasts for each scenario illustrate that plausible urban tree root system architectures—specifically, commonly observed root growth habits—can be produced by RootBox.In-situroot detection (e.g., with an air spade or hydro-vac) at predetermined time intervals can provide model validation and the opportunity to backward reconfigure RootBox parameters for forecast accuracy. Conclusion The adapted RootBox is a flexible, proof-of-concept solution for predicting urban tree root architecture, considering the site and soil conditions pre-established in the planning process. When used with other relevant tools, RootBox can offer valuable insights during the design or rejuvenation of urban spaces.