Assessing Net Environmental and Economic Impacts of Urban Forests: An Online Decision Support Tool

Abstract

Nature-based solutions (NBS) are becoming popular in urban planning and policy making as cost-effective solutions capable of delivering multiple ecosystem services and addressing several societal challenges. So far, however, the cost-effectiveness of urban NBS projects has not been consistently quantified by built environment professionals, who lack user-friendly tools to account for the environmental costs and benefits of NBS. This paper presents a prototype online decision support tool (NBenefit$®) that calculates the negative and positive environmental impacts, externalities, and financial values of planned urban forests over their entire life cycle. NBenefit$ relies on a modelling framework that combines system dynamics, urban ecology, and life cycle thinking approaches, and it is presented as a visual web-based interface. An online map and a grid of cells is used to map the site of intervention, to delineate the size of the urban forest, and to define variations in abiotic, biotic, and management attributes in each site. Outputs are provided by year, for the entire site and NBS life cycle. The potential value of NBenefit$ as a supporting tool was exemplified with the calculation of 48 urban forest archetypes, a few of which were used to set scenarios for a hypothetical urban forest in Madrid (Spain). The results showcase the impact that decisions taken during the planning, design, or management of an NBS project may have on its long-term performance. Future works will expand the scope of NBenefit$, including other types of urban NBS.

Environmental Footprint Neutrality Using Methods and Tools for Natural Capital Accounting in Life Cycle Assessment

“…Figure 5 graphically illustrates the relationships between ES supply and ES demand in terms of potential indicators that can be retrieved from both LCA and ESA literature. The use case in the figure is retrieved and adapted from Babí Almenar et al [92] and includes the typical life cycle phases and ES supply/demand (impact) flows associated with the implementation of green infrastructure in cities (urban forests in this case). The notion of time and space is also included in the source model, but not visualized in the example of Figure 5 for the sake of simplicity.…”

“…Figure 5. Relationship between ES demand and supply indicators in the case of a restoration/renaturation project implemented for residual environmental footprint offsetting purposes; source: core framework and image adapted from Babí Almenar et al[92].…”

A Scoping Review of Urban Planning Decision Support Tools and Processes That Account for the Health, Environment, and Economic Benefits of Trees and Greenspace

“…Among all the studies, only 10 (36%) reported decision support processes that existed in digital formats. A range of methods were employed in the development of these decision frameworks, models, and tools, including stakeholder engagement [45][46][47][48], literature reviews [49][50][51][52], primary data collection [43,44,53], and secondary data analysis [54][55][56][57][58][59][60][61]. Some studies combined methods, such as utilizing both literature reviews and primary data [62,63], both literature reviews and secondary data [64][65][66], both stakeholder engagement and secondary data [67], and both primary and secondary data [68].…”

“…Table 1 presents a summary of the synthesized results and scores for the reviewed frameworks, models, and tools based on how well they incorporate health, environmental, and economic benefits of trees and greenspace. Among the 28 studies analyzed, several patterns emerged: 11 studies [43][44][45][46][48][49][50]59,65,66,69] demonstrated the incorporation of at least one element from each of health, environmental, and economic dimensions; 5 studies integrated benefits from both the environmental and economic dimensions [47,51,[56][57][58]; and 5 studies [51,56,60,64,67,68] combined health and environmental dimensions simultaneously.…”