Sulfur speciation in well-aerated and wetland soils in a forested catchment assessed by sulfur K-edge X-ray absorption near-edge spectroscopy (XANES)

摘要: In forested catchments, retention and remobilization of S in soils wetlands regulate soil water acidification. The prediction long-term budgets forest ecosystems under changing environmental conditions requires a precise quantification all relevant pools, comprising species with different potential. this study, the speciation topsoil horizons toposequence groundwater influence oxygen availability was assessed by synchrotron-based X-ray absorption near-edge spectroscopy (XANES). Our investigation conducted on organic (O, H) mineral (A, AE) Cambisol–Stagnosol–Histosol catena. We studied topography (i.e., degree influence) speciation. Soil sampling pretreatment were anoxic conditions. With increasing decreasing sequence Cambisol–Stagnosol–Histosol, C : ratio humic decreased, indicating an enrichment matter S. Moreover, contribution reduced (inorganic sulfides, thiols) increased systematically at expense intermediate (sulfoxide, sulfite, sulfone, sulfonate) oxidized (ester sulfate, SO). These results support concept S-retention processes for availability. Sulfur contents two water-logged Histosols subject to permanently temporarily oxic conditions, respectively, very different. Histosol, accounted 57% 67% total S; only 43% 54% Again, extent accumulation forms closely reflected O2 study shows that XANES is powerful tool elucidate key patterns biogeochemical cycling environments. contrast traditional wet-chemical methods, it particularly allows distinguish compounds much more detail. It can be used microbial S-metabolism pathways combining inventories repeated analyses sample stages field or laboratory incubation experiments controlled boundary also (sub)microspatial aggregated soils.