Effects of Watershed Acidification on Soil Water and Stream Water Chemistry

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 -

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 - Soil Charge

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 - Mobile Anion Theory

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 - SO cationsNO cations Cation exchange

Ca 2+ Mg 2+ K + 2H + H + H+H+H+H+H+H+H+H+H+H+ Ca 2+ Mg 2+ K +

H+H+H+H+H+H+H+H+H+H+ Ca 2+ Mg 2+ K + SO 4 2- or NO 3 - Base cations in solution pair with mobile anions in solution CaSO 4 or Ca(NO 3 ) 2 MgSO 4 or Mg(NO 3 ) 2 K 2 SO 4 or KNO 3 leach through soil

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 - SO cationsNO cations Leaches from soil Leaches from soil

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 - Acidifies soil and dissolves soil Al 3+

Al 3+ 3H + H+H+H+H+H+H+H+H+H+H+ Al 3+ H+H+H+H+H+H+H+H+ Al Dissolution and Exchange

H+H+H+H+H+H+H+H+H+H+ Al 3+ H+H+H+H+H+H+H+H+ SO 4 2- or NO 3 - Al 2 (SO 4 ) 3 or Al(NO 3 ) 3 leach through soil

Soil Surface H 2 SO 4 HNO 3 SO H + H + + NO 3 - Acidifies soil and dissolves soil Al 3+ SO Al 3+ NO Al 3+ leached to streams & lakes Al 3+ is toxic to aquatic organisms Soluble Al 3+ interferes with plant root functions Al 3+ can reduce plant vigor and growth

 Mobile/excess anions control base cation and acid cation leaching  Base cation leaching = loss of soil base cations/nutrients/fertility  Acid cation leaching results in acidification of soil water and stream water Process Summary

Some of the highest rates in the country Orographic uplifting and high elevation ridges Primary sources – Ohio River Valley

Objective: Gather baseline soil chemistry data across the forest for multiple soil types across multiple geologies Accomplished through a state wide partnership with NRCS Soil Survey Division, West Virginia University, and USFS Over 400 soil pedons characterized in the state 2006 Forest Plan requires monitoring of sensitive areas for the purpose of conducting management activities Wilderness Areas Class 1 Air Monitoring Program Academia

Soil Forming Factors PARENT MATERIAL GEOLOGY WEATHERING RATES Based on geochemistry Compared against 303d impaired stream list for acid rain effects Soils used to ground truth map in sensitive watersheds

Water Chemistry & Watershed Sensitivity on the Monongahela NF

Effects may include:  Decreasing stream pH, ANC, increasing metal concentrations  Declining fish populations and species  Base cation losses in the soil  Foliar macronutrient imbalances  Shifts in biodiversity in the understory vegetation

WATER Effects may include: Changes in Stream chemistry - decreases in Stream pH and ANC High Levels of Iron and Aluminum Nitrogen and Sulfate Leaching from Watershed Soils Ultimately, losses or Shifts in Stream Biota Populations

 Objective: Gather baseline soil chemistry data Forest Wide Watershed Assessments NRCS data collection for soil survey updates Project Specific Soil Disturbing activities Wilderness Areas Class 1 Air Monitoring Program Academia Archive Soil Samples

Anthony Creek Watershed 2007 Sampling High Moderate Low Alluvium

Soil Chemistry Ca:Al Ratios (SrCl 2 Extraction Method; Penn State University Lab) Base Saturation Effective Cation Exchange Capacity (ECEC) Stream Chemistry Foliar Indicators Air Quality

Long harvest rotations 100 years No whole tree harvesting; leave tops and limbs Avoid harvesting in areas with shallow soils Minimize soil disturbance Prescribe fire? Chemical additions ?

Why? Has this been done before? Cost Efficient? Effects Pros and Cons

Cherry River Watershed Lime Dump Cranberry River Watershed Liming Drum Station

Pulses of nitrate and sulfate leaching in the months post application pH does not readily increase in mineral (A, E, and B) horizons Response held to the O, A, and possibly transition horizons (AE, AB, BA, etc.) [Al] and [Mn] decrease, [Ca] and [Mg] increase in soils