Transcript Forest Ecology - Scio School District Page

Forest Ecology
Soil
Forest Ecology
 Time
to Get Dirty
Soils
 For
this presentation we are going to be
‘borrowing’ some information from the
Oregon Envirothon
Soil is …
...an integral part of a
larger ecosystem
affecting both land and
water processes
Soil is …
an ecosystem unto itself
a complex, 3-dimensional habitat
2
1
5
functions
of soil
3
5
4
The five factors of soil formation
Soil = f(cl,o,r,p,t)
 Climate
 Organisms
Active Factors
 Topography/relief
 Parent
 Time
Material
Passive
Factors
Landscape positions
A soil profile
Soil horizons
Soil profile
The “Master” horizons
O
surface horizon made of Organic matter
surface horizon, mineral soil high in organic
matter
 E subsurf. horizon light in color due to leaching
A
B
subsurf horizon, can be high in clay
C
least weathered (and deepest) of all the soil
horizons
R
bedrock
O horizon
Soil has four components
Minerals
Organic
m
matter
O
w
Water
a
Air
w
m
a
m
m
w
m
a
O
m
The four components of soil:
Influence of Texture
Sand
Silt
Clay
Low
Medium
High
Good
Medium
Poor
High
Slow
Very slow
Low
Medium
High
Water-holding capacity
Aeration
Drainage
Nutrient retention
Less
Compaction
Greater
Soils
 Notice
the affect of compaction
 Can you name some ways soil can
become compacted?
 Equipment
 Rain
 Livestock
Soils
 Living
things and their size difference
Relative Sizes
http://commtechlab.msu.edu/sites/dlc-me/zoo/zdrr0101.html
Soil
 Let’s
look at some more information
 Rocks are the parent material for soil
formation
 Soil management
 Logging practices have changed over the
past few decades to help manage the soil
and soil compaction.
 More hi-lead logging is done and logs are
suspended in the air to prevent them from
dragging on the ground
Soils
 Ground
logging has changed to leave
more brush where machines are operating
to reduce compaction
 If skid trails are used, the number is
minimized to reduce compaction and run
off
Soil
 Erosion
 Most
erosion results form road building in the
forests
 Proper road building techniques reduce
erosion
 Recent studies from OSU have shown that
the 1st year after harvest, soil is more likely to
erode than before harvest
 However, after the 1st year, soil is more stable
than before harvest
Soil
 How
is it more stable?
 Before harvest
 Large
conifer trees
 Little brush
 Lot’s of open ground
 After
harvest
 Lots
of brush
 Little open ground
Soil Review