Five years of carbon dioxide fluxes measurements in a highly vegetated suburban area

Suburban areas continue to grow rapidly and are potentially an important land-use category for anthropogenic carbon-dioxide (CO₂) emissions. Here eddy covariance techniques are used to obtain ecosystem-scale measurements of CO₂ fluxes (FC) from a suburban area of Baltimore, Maryland, USA (2002–2006). These are among the first multi-year measurements of FC in a suburban area. The study area is characterized by low population density (1500inhabitants km⁻²) and abundant vegetation (67.4% vegetation land-cover). FC is correlated with photosynthetic active radiation (PAR), soil temperature, and wind direction. Missing hourly FC is gap-filled using empirical relations between FC, PAR, and soil temperature. Diurnal patterns show net CO₂ emissions to the atmosphere during winter and net CO₂ uptake by the surface during summer daytime hours (summer daily total is −1.25gCm⁻²d⁻¹). Despite the large amount of vegetation the suburban area is a net CO₂ source of 361gCm⁻²y⁻¹ on average.