Soil volume and carbon storage shifts in drained and afforested wetlands of the Paraná River Delta

摘要: Wetland ecosystems have a high carbon storage potential as result of primary productivity and low decomposition rates dictated by water saturation. In the herbaceous wetlands Parana River Delta, drainage afforestation with poplars represents one dominant land uses. We explored effects these interventions on volume young sedimentary soils region. At three sites we identified paired stands occupying similar landscape positions soil types but subject to natural flooding covered communities or flood control dikes poplar plantations established 12, 17 19 years ago. Soil sampling at revealed reduction litter compartment (−86 %) decreasing porosity its underlying mineral layer (0–10 cm in wetland reduced 0–4 cm plantation). Our comparisons accounted for volumetric shifts using accumulated mass rather than depth reference, showing that tree gained (22 Mg C ha−1) almost much what they lost litter. These gains were particularly large intermediate depths (4–43 cm plantations) remained unaffected C was raised 64 % explained (1) pulse inputs from overlaying organic layers rapid mobilization after (2) root colonization, since had 75 % their fine biomass depths, whereas roots did not explore profile completely confined layer. A neutral balance following resulted opposing aeration, favoring layer, colonization matter stabilization, accumulation soil.