10.5061/DRYAD.N3S2M
Nidzgorski, Daniel A.
University of Minnesota
Hobbie, Sarah E.
University of Minnesota
Data from: Urban trees reduce nutrient leaching to groundwater
Dryad
dataset
2016
Anthropocene
nutrient pollution
urban trees
groundwater
nutrient leaching
Urban ecosystems
Phosphorus
plant traits
2016-04-05T14:22:37Z
2016-04-05T14:22:37Z
en
https://doi.org/10.1002/15-0976
59388 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Many urban waterways suffer from excess nitrogen (N) and phosphorus (P)
feeding algal blooms, which cause lower water clarity and oxygen levels,
bad odor and taste, and the loss of desirable species. Nutrient movement
from land to water is likely to be influenced by urban vegetation, but
there are few empirical studies addressing this. In this study, we
examined whether or not urban trees can reduce nutrient leaching to
groundwater, an important nutrient export pathway that has received less
attention than stormwater. We characterized leaching beneath thirty-three
trees of fourteen species, and seven open turfgrass areas, across three
city parks in Saint Paul, Minnesota. We installed lysimeters at 60 cm
depth to collect soil water approximately biweekly from July 2011 through
October 2013, except during winter and drought periods, measured dissolved
organic carbon (C), N, and P in soil water, and modeled water fluxes using
the BROOK90 hydrologic model. We also measured soil nutrient pools (bulk C
and N, KCl-extractable inorganic N, Brays-P), tree tissue nutrient
concentrations (C, N, and P of green leaves, leaf litter, and roots), and
canopy size parameters (leaf biomass, leaf area index) to explore
correlations with nutrient leaching. Trees had similar or lower N leaching
than turfgrass in 2012 but higher N leaching in 2013; trees reduced P
leaching compared with turfgrass in both 2012 and 2013, with lower
leaching under deciduous than evergreen trees. Scaling up our measurements
to an urban subwatershed of the Mississippi River (~17,400 ha, containing
roughly 1.5 million trees), we estimated that trees reduced P leaching to
groundwater by 533 kg in 2012 (0.031 kg/ha or 3.1 kg/km2) and 1201 kg in
2013 (0.069 kg/ha or 6.9 kg/km2). Removing these same amounts of P using
stormwater infrastructure would cost $2.2 million and $5.0 million per
year (2012 and 2013 removal amounts, respectively).
Soil water nutrient concentrationsSoil water samples collected in
lysimeters at 60 cm depth, analyzed for nutrient concentrations: total
dissolved organic carbon (NPOC, mg/L), total dissolved nitrogen (TN,
mg/L), nitrate-nitrogen (NO3, mg/L), total dissolved phosphorus (TP,
ug/L), and soluble reactive phosphorus (SRP, ug/L)lysimeter -
dryad.csvSampling site descriptions and traitsInformation for each
sampling site at tree or open turfgrass area: Tree genus/species, diameter
at breast height (DBH) and total tree height; tissue chemistry (% C, N, P)
for leaves, leaf litter, and roots; soil nutrients (KCl-extractable N,
Brays P, and 10d net mineralization and nitrification rates)traits -
dryad.csv
Saint Paul Minnesota USA