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Processes driving nutrient retention in stormwater green infrastructure (SGI) are not well quantified in water-limited biomes. We examined the role of plant diversity and physiochemistry as drivers of microbial community physiology and soil N dynamics post precipitation pulses in a semi-arid region experiencing drought. We conducted our study in bioswales receiving experimental water additions and a montane meadow intercepting natural rainfall. Pulses of water generally elevated soil moisture and pH, stimulated ecoenzyme activity (EEA), and increased the concentration of organic matter, proteins, and N pools in both bioswale and meadow soils. Microbial community growth was static, and N assimilation into biomass was limited across pulse events. Unvegetated plots had greater soil moisture than vegetated plots at the bioswale site, yet we detected no clear effect of plant diversity on microbial C:N ratios, EEAs, organic matter content, and N pools. Differences in soil N concentrations in bioswales and the meadow were most directly correlated to changes in organic matter content mediated by ecoenzyme expression and the balance of C, N, and P resources available to microbial communities. Our results add to growing evidence that SGI ecological function is largely comparable to neighboring natural vegetated systems, particularly when soil media and water availability are similar.
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Ecohydrology of Green Stormwater Infrastructure in Shrinking Cities: A Two-Year Case Study of a Retrofitted Bioswale in Detroit, MI
Stormwater management is of great importance in large shrinking cities with aging and outdated infrastructure. Maintenance of vegetated areas, particularly referred to as green infrastructure, is often aimed at mitigating flooding and the urban heat island effect by stormwater storage and evaporative cooling, respectively. This approach has been applied in large cities as a cost-effective and eco-friendly solution. However, the ecohydrological processes and how the ecohydrology influences the function of green infrastructure and its potential to provide those ecosystem services are not well understood. In this study, continuous field measurements including air temperature, stomatal conductance, and phenocam images were taken in a 308 m2 bioswale retrofitted into a 4063 m2 parking lot on the Wayne State University campus in Detroit, Michigan over a two-year period. Our results suggest that plant characteristics such as water use efficiency impact the ecohydrological processes within bioswales and that retrofitted bioswales will need to be adapted over time to meet environmental demands to allow for full and sustained success. Therefore, projected shifts in precipitation regime change are expected to affect the performance of green infrastructure, and each bioswale needs to be developed and engineered to be able to adapt to changing rainfall patterns.
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- Award ID(s):
- 2126206
- PAR ID:
- 10454951
- Date Published:
- Journal Name:
- Water
- Volume:
- 14
- Issue:
- 19
- ISSN:
- 2073-4441
- Page Range / eLocation ID:
- 3064
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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African American communities experience higher incidences of health disparities due to inequitable exposures to environmental stressors. With the increase of climate threats, stormwater runoff and flooding are major concerns that can be linked to environmental injustice in African American communities, including illegal dumping, and even proximity to major highways. Efforts to improve stormwater ( management overlap with efforts to increase green space through the implementation of urban green infrastructure ( presenting the opportunity for UGIUGIto be utilized as a measure to improve geographical and social equity. However there are still many communities who have yet to transition into using green infrastructure for SW management and research is limited on how equitable current stormwater best management practices(SW BMPs) are, particularly in regards to management processes and decisions . The goal of this research is to characterize SW infrastructure in an African American community in Tampa, East Tampa, through the lens of sustainability and environmental justice to better inform management practices towards equitable management of SW infrastructure in the community.more » « less
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Integrating the Spatial Configurations of Green and Gray Infrastructure in Urban Stormwater NetworksAbstract Green infrastructure (GI) practices improve stormwater quality and reduce urban flooding, but as urban hydrology is highly controlled by its associated gray infrastructure (e.g., stormwater pipe network), GI's watershed‐scale performance depends on its siting within its associated watershed. Although many stormwater practitioners have begun considering GI's spatial configuration within a larger watershed, few approaches allow for flexible scenario exploration, which can untangle GI's interaction with gray infrastructure network and assess its effects on watershed hydrology. To address the gap in integrated gray‐green infrastructure planning, we used an exploratory model to examine gray‐green infrastructure performance using synthetic stormwater networks with varying degrees of flow path meandering, informed by analysis on stormwater networks from the Minneapolis‐St. Paul Metropolitan Area, MN, USA. Superimposed with different coverage and placements of GI (e.g., bioretention cells), these gray‐green stormwater networks are then subjected to different rainfall intensities within Environmental Protection Agency's Storm Water Management Model to simulate their hydrological benefits (e.g., peak flow reduction, flood reduction). Although only limited choices of green and gray infrastructure were explored, the results show that the gray infrastructure's spatial configuration can introduce tradeoffs between increased peak flow and increased flooding, and further interacts with GI coverage and placement to reduce peak flow and flooding at low rainfall intensity. However, as rainfall intensifies, GI ceases to reduce peak flow. For integrated gray‐green infrastructure planning, our results suggest that physical constraints of the stormwater networks and the range of rainfall intensities must be considered when implementing GI.more » « less
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In 2021, Environmental Science & Technology convened an ACS Global Webinara on green stormwater infrastructure (GSI) as a tool for environmental justice. Since then, we researchers have continued to discuss advancing GSI science, practice, and priorities. The U.S. Environmental Protection Agency (1) describes green infrastructure as “the range of measures that use plant or soil systems, permeable pavement or other permeable surfaces or substrates, stormwater harvest and reuse, or landscaping to store, infiltrate, or evapotranspirate stormwater and reduce flows to sewer systems or to surface waters.” GSI systems use a variety of names both within the United States and worldwide (e.g., low-impact development, sponge cities, water sensitive cities) and encompasses concepts from physical stormwater design/management practices to sustainable urban planning and urban ecology. (2,3) GSI and, more broadly, other nature-based solutions offer possibilities for improving urban hydrologic function and water quality while providing multiple co-benefits; (4) however, we contend the most important benefit is as a tool to advance environmental justice (EJ). Indeed, if these benefits lack intentionality in process and placement to repair past harms, we miss the greatest opportunity of all. Here we present summarized thoughts concerning strengths, weaknesses and threats, and opportunities for GSI (Figure 1).more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/w14193064
