Impact of vegetation selection on nitrogen and phosphorus processing in bioretention containers.
A year-long bioretention container study in Maryland, USA, measured the relationship between three plant species (Eutrochium dubium, Iris versicolor, and Juncus effusus) and N (  ,  ,  , total nitrogen [TN], total dissolved nitrogen [TDN], dissolved organic nitrogen, particulate organic nitrogen [PON]) and total phosphorus (TP) removal from synthetic stormwater. Statistically significant removal was only found for  and TP. Plant-independent  removal occurred 9 months after planting, and then changed to removal only by the least-densely planted Juncus treatment. Removal in higher-density Juncus plantings was suspected to be limited by preferential pathways created by high root density. Juncus' low-density  removal success correlates with its high growth rate, root mass and length, and large biomass, matching previous literature. TP removal was plant-independent. Shoot harvesting of one plant of each species after 1 year would remove 0.61 g N. Of the plant species in this study, Juncus effusus is most highly recommended for bioretention for its nutrient removal dynamics and year-round green aesthetics. PRACTITIONER POINTS: Only the one-Juncus density treatment had significant  removal. All Juncus treatments as well as non-Juncus treatments prevented the PON, TN, or TDN export seen in the No-plants control. TP removal was plant-independent. Juncus had the greatest biomass increase and biomass N. Shoots contain the majority of biomass N for each plant species. Juncus and Iris had high survivorship. Joe Pye had low survivorship. These, and all other study results, need field-scale verification.
['Muerdter|Claire P|CP|https://orcid.org/0000-0002-2576-0538', 'Smith|Daniel J|DJ|https://orcid.org/0000-0002-6266-7754', 'Davis|Allen P|AP|https://orcid.org/0000-0001-7818-1890']
D018533:Biomass D008396:Maryland D009584:Nitrogen D010758:Phosphorus D014874:Water Pollutants, Chemical
stormwater biological treatment nitrogen removal remediation surface water