Post on 20-Jan-2016
Forest EcologyForest Ecology
SoilSoil
Forest EcologyForest Ecology
Time to Get DirtyTime to Get Dirty
SoilsSoils
For this presentation we are going to be For this presentation we are going to be ‘borrowing’ some information from the ‘borrowing’ some information from the Oregon EnvirothonOregon Envirothon
Soil is …Soil is …
...an integral part of a ...an integral part of a
larger ecosystemlarger ecosystem
affecting both land and affecting both land and
water processeswater processes
Soil is …Soil is …
an ecosystem unto itself an ecosystem unto itself
a complex, 3-dimensional habitata complex, 3-dimensional habitat
5 functions
of soil
1
54
3
2
The five factors of soil formationThe five factors of soil formation
ClimateClimate OrganismsOrganisms Topography/reliefTopography/relief Parent MaterialParent Material TimeTime
Soil = f(cl,o,r,p,t)
Passive Factors
Active Factors
Landscape positionsLandscape positions
A soil profile
Soil profile
Soil horizons
O O
AA
EE
BB
CC
RR
The “Master” horizonsThe “Master” horizons
surface horizon made of Organic matter
surface horizon, mineral soil high in organic matter
subsurf. horizon light in color due to leaching
subsurf horizon, can be high in clay
least weathered (and deepest) of all the soil horizons
bedrock
O horizon
Minerals Minerals Organic matter Organic matter WaterWater AirAir
Soil has four componentsSoil has four components
mm
mm
mm mmmm
mm
O
O
w
ww
a a
a
The four components of soil:
Influence of TextureSand Silt Clay
Water-holding capacity
Aeration
Drainage
Nutrient retention
Low Medium High
Good PoorMedium
Slow Very slowHigh
HighLow Medium
Less GreaterCompaction
SoilsSoils
Notice the affect of compactionNotice the affect of compaction Can you name some ways soil can Can you name some ways soil can
become compacted?become compacted? EquipmentEquipment RainRain LivestockLivestock
SoilsSoils
Living things and their size differenceLiving things and their size difference
Relative Sizes
http://commtechlab.msu.edu/sites/dlc-me/zoo/zdrr0101.html
SoilSoil
Let’s look at some more informationLet’s look at some more information Rocks are the parent material for soil Rocks are the parent material for soil
formationformation Soil managementSoil management Logging practices have changed over the Logging practices have changed over the
past few decades to help manage the soil past few decades to help manage the soil and soil compaction. and soil compaction.
More hi-lead logging is done and logs are More hi-lead logging is done and logs are suspended in the air to prevent them from suspended in the air to prevent them from dragging on the grounddragging on the ground
SoilsSoils
Ground logging has changed to leave Ground logging has changed to leave more brush where machines are operating more brush where machines are operating to reduce compactionto reduce compaction
If skid trails are used, the number is If skid trails are used, the number is minimized to reduce compaction and run minimized to reduce compaction and run offoff
SoilSoil
ErosionErosion Most erosion results form road building in the Most erosion results form road building in the
forestsforests Proper road building techniques reduce erosion Proper road building techniques reduce erosion Recent studies from OSU have shown that the Recent studies from OSU have shown that the
11stst year after harvest, soil is more likely to erode year after harvest, soil is more likely to erode than before harvestthan before harvest
However, after the 1However, after the 1stst year, soil is more stable year, soil is more stable than before harvestthan before harvest
SoilSoil
How is it more stable?How is it more stable? Before harvestBefore harvest
Large conifer treesLarge conifer trees Little brushLittle brush Lot’s of open groundLot’s of open ground
After harvestAfter harvest Lots of brushLots of brush Little open groundLittle open ground
Soil ReviewSoil Review