fear and leaching in michigan or, dude, where’s my nutrients?
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Fear and Leaching in Michigan or, Dude, where’s my nutrients?. Emily Farrer, Joshua Haag, Joel Perkovich , Katherine Windfeldt. Introduction. Properties of Soil Physical Chemical Biological Synthesis of Lab and Field Data The Development of a Northern Oak Ecosystem. - PowerPoint PPT PresentationTRANSCRIPT
Fear and Leaching in Michigan
or,
Dude, where’s my nutrients?
Fear and Leaching in Michigan
or,
Dude, where’s my nutrients?
Emily Farrer, Joshua Haag, Joel Perkovich , Katherine Windfeldt
IntroductionIntroduction
Properties of SoilPhysicalChemicalBiological
Synthesis of Lab and Field Data The Development of a Northern Oak Ecosystem
Physical Properties of SoilPhysical Properties of Soil Texture
– Sand
H20 Holding Capacity– 0.12 cm3 H2O/cm3 Soil– Lowest of all sites
Bulk Density– 1.1 g/cm3 – 2nd Lowest behind NH
Chemical AnalysesChemical Analyses
CEC - Lowest CEC of all sites at 2.2 cmolc/kg (other sites range 3.86-8.71 cmolc/kg)- Thus, smallest nutrient holding capacity of all soils
Base Saturation - Lowest BS of all sites at just 13% (other sites range from 97-99%)
pH- Most acidic of all sites at 4.21 (Mixed Oak highest pH at 5.97)
Soil Biological PropertiesSoil Biological PropertiesProperty Value Relative amount
Soil organic matter 3.06% lowest
Microbial biomass 5.3 g/m2 lowest (w/ OH)
Microbial respiration 12.9 ug/g/d lowest
Specific respiration 304 mg/g/d intermediate(OH higher)
Net mineralization 0.098 g/m2/d lowest
Nitrification 0.002 g/m2/d lowest
C resp./N min. 14.3 ugC/ugN intermediate (MO lower)
Ecosystem Biological PropertiesEcosystem Biological Properties
Ecosystem Biomass
Mg/ha % total
Aboveground
179.0 79.7
Forest Floor 11.5 5.1
Soil 34.0 15.1
Nitrogen Pools
kg/ha % total
Aboveground
392.7 24.8
Forest Floor 86.2 5.4
Soil1105.
069.8
Low ecosystem biomass and N compared to other forests
Aboveground and forest floor second lowest (OH lowest)Soil biomass and N pools lowest
Structure / Texture- Well-sorted, sandy PM from former lake bed = larger particle size, weak structure and
sandy texture
Bulk Density (Db)- Well-sorted (homogenous), loosely packed soil results in second lowest Db
` at 1.1 gm/cm3 (other sites range 1.02-1.34)
CEC / Base Saturation - Lowest CEC at 2.2 cmolc/kg 90% sand and 3% clay = weak electronegative charge for CEC- Lowest BS at 13%
Role of topography / fire and well-drained sandy PM = nutrient loss
Available Water Content- Lowest AWC at 0.12 cm3 H20/cm3 soil (other sites range 0.14-0.44)- well-drained sandy PM, lower elevation and southern aspect = H20 loss
pH - Most acidic at 4.21, Non-calcareous PM offers no buffer for soil acidification via weathering
Northern Oak PhysiographyNorthern Oak Physiography
Soil: Field and LabSoil: Field and Lab
Sandy and acidic throughoutLab data supported
Little structureLow OM
Moderately shallow, weak profileWell-drained – weatheringLow OM, no humus accum.
O horizon thinA shallow
Low biomass in forest floor and soil
E weak Bs weak C sand
Profile
SOM rules!SOM rules!
SOMWater holding capacity
Structure
Color
CEC (& anion EC)
Base SaturationpH
Microbial biomassMicrobial respiration N mineralization NPP
VegetationVegetationHistory
1880’s white pine logged, big burnNatural fire regime until 1930 when human fire suppression began
CompositionOverstory– black oak, white oak, red oak, red maple
Understory / Ground Cover– white pine, red maple, sassafras, blueberry, wintergreen,
Pensylvania sedge
VegetationVegetationLow Biomass - 224 Mg/ha
Lowest AWC 0.12 cm3 H2O/cm3 soilLowest Nutrient Availability
– Nitrogen content of 1584 kg/ha– CEC of 2.2 cmol/kg– BS of 0.13
Species Composition – Dry/AcidicLowest AWC 0.12 cm3 H2O/cm3 soilLowest Nutrient Availability Lowest pH of 4.21Fire regime
Perpetuation of systemFire regime/Dry siteOak species
The Development of a Northern Oak Ecosystem
The Development of a Northern Oak Ecosystem
•Young soil•Limited weathering•Low CEC (and non-calcareous parent material) •Well drained (low FC and AWC) -> Loss of nutrients by leaching
Nutrients CEC
Soil Development and Ecosystem Feedbacks
Soil Development and Ecosystem Feedbacks
SOM
Nutrients CEC
•Few nutrients -> low biomass•Low biomass -> little SOM•Little SOM -> Low CEC•Loss of nutrients by leaching
Soil Development and Ecosystem Feedbacks
Soil Development and Ecosystem Feedbacks
Nutrients CEC
Nutrients
•Physiographic and topographic characteristics -> prone to fire
•Loss of nutrients by burning and leaching
Summary:Summary: Young, relatively unweathered soil Susceptible to leaching
Loss of nutrientsLow productivity and biomassLow SOM and CEC
Susceptible to fireLoss of nutrientsLow productivity and biomassLow SOM and CEC
Positive feedbacks maintain low biomass