Quantifying Green-Water Outputs in an Urban Watershed
Faculty Mentor Information
Keith Reinhardt Dr., Idaho State University
Abstract
Urban greenspaces are highly sought after by citizens for their beauty, recreation, and ecosystem services. These greenspaces come at a cost, however. The arid conditions of the Snake River Plain can require large volumes of irrigation to grow, especially if plants are not native and/or are not “water-wise”. City planners have a good understanding of the amount of water which enters (e.g., precipitation and capturing of aquifer water) and leaves (e.g., via sewage treatment plants) an urban watershed, yet little is understood about how much water leaves via plant transpiration and evaporation. Quantifying these plant water-losses is a critical first step in managing water budgets, but such tests rarely occur. To address this knowledge gap we measured the hydraulic transport capacity in waterwise and non-waterwise species in both irrigated and nonirrigated sites in Pocatello. To do this, ring width and conduit density and diameter in cross-sections of branch segments were measured. We hypothesized that non-waterwise plants would have xylem traits characteristic of greater hydraulic transport capacity compared to waterwise plants. We further hypothesized that the xylem architecture of waterwise plants would be less affected by irrigation status compared to non-waterwise plants, reflecting less susceptibility to drought.
Quantifying Green-Water Outputs in an Urban Watershed
Urban greenspaces are highly sought after by citizens for their beauty, recreation, and ecosystem services. These greenspaces come at a cost, however. The arid conditions of the Snake River Plain can require large volumes of irrigation to grow, especially if plants are not native and/or are not “water-wise”. City planners have a good understanding of the amount of water which enters (e.g., precipitation and capturing of aquifer water) and leaves (e.g., via sewage treatment plants) an urban watershed, yet little is understood about how much water leaves via plant transpiration and evaporation. Quantifying these plant water-losses is a critical first step in managing water budgets, but such tests rarely occur. To address this knowledge gap we measured the hydraulic transport capacity in waterwise and non-waterwise species in both irrigated and nonirrigated sites in Pocatello. To do this, ring width and conduit density and diameter in cross-sections of branch segments were measured. We hypothesized that non-waterwise plants would have xylem traits characteristic of greater hydraulic transport capacity compared to waterwise plants. We further hypothesized that the xylem architecture of waterwise plants would be less affected by irrigation status compared to non-waterwise plants, reflecting less susceptibility to drought.