Author : Viswanathan, B. Volder, A. Watson, W. T. Aitkenhead-Peterson, J. A.
Year : 2011
Title : Impervious and pervious pavements increase soil CO2 concentrations and reduce root production of American sweetgum (Liquidambar styraciflua)
Journal : Urban Forestry & Urban Greening
Comment : Most reported Rs rates range between 0 and 10 μmol m-2 s-1. However, their results show that Rs rates for soils covered with concrete treatments were 5 to 20 times greater. Such extremely high efflux rates were likely due to pavement blocking the natural efflux of CO2 out of the root zone. Reduced flow of CO2 out of the soil then leads to accumulation of high amounts of CO2 under the concrete. Since CO2 efflux is partially governed by the concentration difference between soil and air, and other soil and atmospheric conditions were very similar across the plots, they would expect that soils with a greater standing CO2 concentration would also exhibit a greater soil CO2 efflux.