Join the Minnesota Stormwater Series in person or online on January 15, 2026 at 10am (US central time)
Abstract: Trees are ubiquitous in urban environments and are appreciated for a range of ecosystem services. However, the tradeoff in their ability to reduce stormwater runoff volumes versus their potential contributions of nutrient and coarse organic matter in dissolved and particulate forms has been largely ignored in stormwater management practices due to lack of robust data. Our project has now filled some of these data gaps through a three-year monitoring effort to quantify tree-scale water quantity and quality fluxes across eighteen ash (Fraxinus spp.) trees and four maple (Acer spp.) trees in the city of St. Paul.
We also examine how these local measurements and seasonal patterns relate to corresponding watershed-level stormwater observations. Our results revealed that throughfall nutrient fluxes were higher under trees than in open precipitation, despite an overall reduction in water volumes due to canopy interception. Nevertheless, these nutrient contributions can potentially be mitigated through improved tree health, which also increases soil water uptake through enhanced evapotranspiration. Finally, leaf litter nutrient content progressively declined closer to the pavement curb, suggesting that trees near and overhanging impervious road surfaces can contribute throughfall nutrient fluxes that quickly enter the stormwater network.
DATE & TIME: Thursday, January 15, 2026, 10a - 12p US Central
In-person: St. Anthony Falls Laboratory Auditorium (2 Third Ave SE, Minneapolis, MN)
Online: https://z.umn.edu/mn-stormwater-seminar-series (active 10 minutes prior)
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