Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil measurements

J Barba, A Cueva, M Bahn, GA Barron-Gafford , B Bond-Lamberty, PJ Hanson, A Jaimes, Liisa-Maija Kulmala, J Pumpanen, RL Scott, G Wohlfahrt, R Vargas

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Sammanfattning

The net ecosystem exchange (NEE) is the difference between ecosystem CO2 assimilation and CO2 losses to the atmosphere. Ecosystem respiration (R-eco), the efflux of CO2 from the ecosystem to the atmosphere, includes the soil-to-atmosphere carbon flux (i.e., soil respiration; R-soil) and aboveground plant respiration. Therefore, R-soil is a fraction of R-eco and theoretically has to be smaller than R-eco at daily, seasonal, and annual scales. However, several studies estimating R-eco with the eddy covariance technique and measuring R-soll within the footprint of the tower have reported higher R-soil than R-eco, at different time scales. Here, we compare four different and contrasting ecosystems (from forest to grasslands, and from boreal to semiarid) to test if measurements of R-eco are consistently higher than R-soil. In general, both fluxes showed similar temporal patterns, but R-eco, was not consistently higher than R-soil from daily to annual scales across sites. We identified several issues that apply for measuring NEE and measuring/upscaling R-soil that could result in an underestimation of R-eco and/or an overestimation of R-soil. These issues are discussed based on (a) nighttime measurements of NEE, (b) R-soil measurements, and (c) the interpretation of the functional relationships of these fluxes with temperature (i.e., Q(10)). We highlight that there is still a need for better integration of R-soil with eddy covariance measurements to address challenges related to the spatial and temporal variability of R-eco, and R-soil.
Originalspråkengelska
TidskriftAgricultural and Forest Meteorology
Volym249
Sidor (från-till)434-443
Antal sidor10
ISSN0168-1923
DOI
StatusPublicerad - 15 feb 2018
MoE-publikationstypA1 Tidskriftsartikel-refererad

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  • 1172 Miljövetenskap
  • 4112 Skogsvetenskap

Citera det här

Barba, J., Cueva, A., Bahn, M., Barron-Gafford , GA., Bond-Lamberty, B., Hanson, PJ., ... Vargas, R. (2018). Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil measurements. Agricultural and Forest Meteorology, 249, 434-443. https://doi.org/10.1016/j.agrformet.2017.10.028