Benchmarks for atmospheric deposition of acidifying substances for terrestrial ecosystems in Alberta were developed using the steady-state mass balance (SSMB) model. The SSMB model considers both biological response and soil buffering capacity. Alberta soil characteristics, dominant vegetation cover, run off, biomass harvest and grazing, base cation deposition and the impact of wildfires are used to derive these benchmarks or critical loads of acidity for sulphur and nitrogen deposition. This document provides critical load values necessary for acid deposition assessments carried out under the revised 2022 Acid Deposition Management Framework for Alberta. The report outlines the methods used to determine these critical load values and is a companion document to the revised framework.
