Calculating critical loads of acid deposition with PROFILE ? A steady-state soil chemistry model

A proposal to measure absolute environmental sustainability in life cycle assessment

“…At this point the functioning of the soil ecosystem starts changing as the carbonate buffering system is weakening and additional depositions will bring the system close to its chemical pH threshold. 2 Based on a screening of pH curves modelled with the geochemical steady-state model PROFILE (Warfvinge and Sverdrup, 1992) we found that a pH decrease of 0.25, compared to natural pH, generally corresponded well with this point where pH starts responding non-linearly to additional depositions (see S2). The second threshold was required to take into account naturally acidic soils for which the critical factor threatening ecosystem structure is not pH decrease, but rather the mobilisation of toxic aluminium (III) from the buffering of acid depositions through reaction with aluminium oxides and hydroxides from clay particles (Sparks, 2002).…”

Characterizing base-cation immobilization in the stem of six hardwoods of eastern Canada

“…Mineral weathering was estimated using the steadystate model PROFILE [39]. Ranges of soil properties used for estimating weathering rates in Saint-Bernard and Sainte-Sophie soils are presented in table I.…”

Modelling and mapping critical loads and exceedances for the Georgia Basin, British Columbia, using a zero base-cation depletion criterion

“…Generally, Eqn 3 produced soil weathering rates similar in range and magnitude compared to those obtained through more detailed means (see, e.g., Hodson & Langan 1999; Akselsson et al 2004;Ouimet & Duchesne 2005;Mongeon et al 2010, this issue). Nevertheless, and ideally, soil weathering estimates should be derived from actual soil mineral contents and knowledge of reactive soil surfaces, by soil layer (Warfvinge & Sverdrup 1992;Whitfield et al 2006;Whitfield et al 2010, this issue), (iii) refining the atmospheric deposition loads for dry and wet deposition (Boulton et al 2009) within the context of contemplated and actual air pollution abatement policies and targets, (iv) adding a detailed forest inventory component to address BC and N related harvest exports , (v) examining results of standand watershed-based nutrient input/output investigations, especially within the study region (Feller et al 2000;Feller 2005;Feller 2010, this issue), and (vi) dealing with BC and N uptake in a locally systematic fashion, based on, e.g., detailed forest management plans. Systematic investigations pertaining to vegetation-, landform-and topography-induced variations in soil mineralogy, depth, texture, organic matter, pH, CEC, BS, and soil drainage would also be helpful.…”