1. Introduction.- Purpose of the assessment.- Structure of the assessment.- Background on why this has become an important topic.- Lakes versus forests.- Concerns over effects on forests.- Pathways of acidic deposition impacts.- The uncertain nature of truth in ecosystem studies.- 2. The nature of soil acidity and H+ budgets.- Weak acid behavior of soils.- Changes in soil acidity involving the dynamics of weak and strong acids.- Sulfur, nitrogen and H+ budgets.- Loblolly pine case studies.- 3. Magnitudes and patterns of nitrogen and sulfur deposition in the South.- Sources of acids in the atmosphere.- Anthropogenic emissions of sulfur and nitrogen.- Modes of deposition.- Atmospheric deposition in the South.- Trends in deposition rates.- 4. Forest soils of the South.- Climate.- Regional geomorphology and soils.- Coastal Plain.- Mississippi River Valley.- Piedmont.- Blue Ridge.- Ridge and Valley.- Appalachian Plateaus.- Interior Low Plateau.- Ouachita Uplands.- Ozark Plateau.- Central Lowlands.- Importance in soil acidification.- 5. Previous evaluations of sensitivity of southern soils.- Site-specific studies.- Previous regional assessments of soil sensitivity to acidic deposition.- Critique of criteria for gauging soil sensitivity.- 6. Nutrient cycles and nutrient limitations in the South.- The nitrogen cycle.- The sulfur cycle.- The nutrient cation cycles.- Cycles of other elements.- Nutrient limitations on forest growth in the South.- Conclusions.- 7. Simulation of the potential impacts of acidic deposition on forest soils in the South.- The MAGIC model.- Our approach.- Simulation results.- Discussion of simulation results and implications.- Conclusions from simulations.- 8. Synthesis and recommendations.- References.