effects of watershed acidification on soil water and stream water chemistry
DESCRIPTION
Effects of Watershed Acidification on Soil Water and Stream Water Chemistry. H 2 SO 4. HNO 3. Soil Surface. SO 4 2- + H +. H + + NO 3 -. H 2 SO 4. HNO 3. Soil Surface. SO 4 2- + H +. H + + NO 3 -. Soil Charge. H 2 SO 4. HNO 3. Soil Surface. SO 4 2- + H +. - PowerPoint PPT PresentationTRANSCRIPT
Effects of Watershed Acidification on Soil Water and
Stream Water Chemistry
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
Soil Charge
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
Mobile Anion Theory
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
SO42- + cations NO3
- + cationsCation exchange
Ca2+
Mg2
+
K+
2H+
2H+
H+
H+
H+
H+
H+
H+
Ca2+
Mg2
+
K+
H+
H+
H+
H+
H+
Ca2+
Mg2
+
K+
SO42- or
NO3-
SO42- or
NO3-
SO42- or
NO3-
Base cations in solution pair with mobile anions in solution
CaSO4 or Ca(NO3)2
MgSO4 or Mg(NO3)2
K2SO4 or KNO3
leach through soil
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
SO42- + cations NO3
- + cations
Leachesfrom soil
Leachesfrom soil
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
Acidifies soil anddissolves soil Al3+
Al3+
Al3+
Al3+
3H+
3H+
3H+
H+
H+
H+
H+
H+
Al3+
Al3+
Al3+
H+
H+
H+
H+
Al Dissolution
and Exchange
H+
H+
H+
H+
H+
Al3+
Al3+
Al3+
H+
H+
H+
H+
SO42- or
NO3-
SO42- or
NO3-
SO42- or
NO3-Al2(SO4)3 or
Al(NO3)3
leach through soil
Soil Surface
H2SO4 HNO3
SO42- + H+ H+ + NO3
-
Acidifies soil anddissolves soil Al3+
SO42- + Al3+
NO3- + Al3+
leached to streams & lakes
Al3+ is toxic to aquaticorganisms
Soluble Al3+
interferes with plant rootfunctions
Al3+ can reduce plant vigorand 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
Sulfate Deposition across the NESome 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 Chemistry Monitoring Program
Acid Deposition Sensitivity MapSoil Forming Factors
PARENT MATERIALGEOLOGY WEATHERING RATES
Based on geochemistry
Compared against 303d impaired stream list for acid rain effects
Soils used to ground truth map in sensitive watersheds
Resource Effects - Acid DepositionWater Chemistry & Watershed Sensitivity on the Monongahela
NF
Non-Management EffectsEffects 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
Resource EffectsAcid DepositionWATEREffects 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
Soil Chemistry Monitoring Program Objective: Gather
baseline soil chemistry data
Forest Wide Watershed Assessments NRCS data collection for
soil survey updatesProject Specific
Soil Disturbing activitiesWilderness Areas
Class 1 Air Monitoring Program
AcademiaArchive Soil Samples
Anthony Creek Watershed 2007 Sampling
High ModerateLowAlluvium
Criteria Used to Assess RiskSoil Chemistry
Ca:Al Ratios (SrCl2 Extraction Method; Penn State University Lab)
Base Saturation Effective Cation
Exchange Capacity (ECEC)
Stream Chemistry Foliar IndicatorsAir Quality
Long harvest rotations 100 yearsNo whole tree harvesting; leave tops
and limbsAvoid harvesting in areas with
shallow soilsMinimize soil disturbancePrescribe fire?Chemical additions ?
Mitigations
LimingWhy?Has this been done
before?Cost Efficient?Effects
Pros and Cons
Stream Liming
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
Effects to the Soil from Liming