Soil microbial nitrogen cycling and nitrous oxide emissions from urban afforestation in the New York City Afforestation Project

•We measured soil nitrous oxide (N2O) emissions from the New York City Afforestation Project (NY-CAP) forest plots with varied approaches to site preparation.•We measured similar fluxes of N2O from plots planted with trees only and plots planted with trees and shrubs (p>0.05).•We observed lower N2O fluxes from plots with one time amendment with compost compared to plots without compost amendment.•Higher N2O emissions (∼0.05ngNcm−2h−1) from plots with no shrubs and no compost suggest that plant and microbial uptake of inorganic N in urban afforestation projects are important factors in regulating and inhibiting N2O loss from soils.•Site preparation with shrubs and compost amendment in urban afforestation projects may tighten soil N cycling by preventing N2O losses from urban soils.