کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4573909 | 1629503 | 2012 | 10 صفحه PDF | دانلود رایگان |
Spatial variability of greenhouse gas (GHG) emissions from agricultural lands is not well known although it has a great impact on the accuracy of GHG budget.The objectives of this study were to assess the spatial variability of CO2 emission fluxes (CO2-flux) and correlate these emissions with soil physico-chemical properties at two spatial scales and at different depths using a new geostatistical approach (coregionalization analysis with a drift, CRAD) that performs multiscale spatial analysis.Two agricultural sites with sandy and loamy soils were instrumented at 108 geo-referred sampling points and at two depths during spring 2007 where soil surface CO2-flux and soil physico-chemical parameters were measured. The CO2-flux presented spatial patterns characterized by different scales (i.e., non-spatial, small spatial and large spatial scale components), each describing a different fraction of its variability. About a quarter of CO2-flux variability at the first site and one fifth at the other site was attributed to the non-spatial component. Strongest correlations were obtained between CO2-flux and soil temperature, water saturation (Sw), elevation, electrical conductivity, soil bulk density, and the C/N ratio, but with differences between sites. Correlations were much stronger at large scale. Analyzing correlations between CO2-flux and soil properties without discriminating for scales can miss important scale-dependent processes controlling soil gas emissions. Scales at which these processes vary should therefore be taken into account.
► Multiscale correlations between greenhouse gas emissions and soil.
► Correlations between emissions and soil properties change between scales.
► CO2-flux was correlated with physical properties.
► Gas diffusion process alone is not sufficient for predicting CO2-flux.
Journal: Geoderma - Volume 170, 15 January 2012, Pages 251–260