Chemical rock weathering in forest soils - Measurable quantity or dummy variable : Annual Meetings American Society of Agronomy, Crop Science Society of America, Soil Science Society of America
Chemical weathering is in the long run the only de-acidifying process in forest soils. It compensates for acidification dure to nutrient uptake, mineralization, and leaching losses. Precise measurements of weathering are required for mass balance studies at the estimation of 'critical loads'. Our efforts to properly assess base cation replenishment are compromised when required parameters are unavailable in the desired quality. Two case studies dealing with vitality of forests on acidic nutrient poor soils are presented. Major nutrient fluxes are estimated. Chemical weathering would be the key process to interpret changes in soil nutrient status. I pinpoint uncertainties of parameters used to estimate the rate of weathering and show that delicate changes of forest growth have a stronger impact on cation budgets than weathering rate. I will present the refinement of my input data set by both defining set by both defining the mineral composition of the soil and defining the pathway of the weathering process.
