soil as an ecosystem

SOIL AS AN ECOSYSTEM
What do we know about soil
now?
• What makes up soil?
• What lives there?
• Where does soil come from?
• How does soil contribute to
the ecological community of
place?
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
The soil ecosystem is called “The
Pedosphere” (From the root word
pedology, which means the study
of soil).
What other geospheres, or
global regions do we study in
science?
CLICK HERE to see how the
Pedosphere connects to other
cycles and spheres on the planet.
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Some terms we should learn to
talk about soils:
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Some terms we should learn to talk about soils:
• Definition: Ecosystem:
An interacting natural environment which includes all the
animal and plant life that is found.
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Some terms we should learn to talk about soils:
Definition: Organic:
Materials that contain carbon compounds. Most living
things contain carbon compounds.
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Some terms we should learn to talk about soils:
Definition: Organic:
Materials that contain carbon compounds. Most living
things contain carbon compounds.
Definition: Inorganic:
Materials such as minerals that are not products of
organic life.
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Parts of a Soil Ecosystem:
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Soil Air: Pore
spaces for the
exchange of
gases.
Soil Water:
Stored in the soil
for plant use.
Contains
important
nutrients for
plant growth.
Soil Organic
Matter: Organic
materials and
biological life
that is
incorporated into
the soil.
Soil Minerals:
rocks and soil
particles that
make up soil
solids.
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Soil Air:
About 25%
Soil Organic
Matter:
About 6%
Soil Water:
About 25%
Soil Minerals:
About 44%
INTRODUCTION TO SOILS FIELD STUDY

SOIL AS AN ECOSYSTEM
Soil Air:
About 25%
Soil Organic
Mater:
About 6%
Soil Water:
About 25%
Soil Minerals:
About 44%
INTRODUCTION TO SOILS FIELD STUDY

HOW SOIL FORMS
5 Factors in the landscape combine to
make the soil we find in a place and
define the characteristics that soil will
have.
INTRODUCTION TO SOILS FIELD STUDY

HOW SOIL FORMS
Factor 1: Parent Material
Definition:
Any material from which soil is formed.
Whether it is bedrock found
in place, volcanic debris,
material that has been blown
in by wind, or carried and
deposited by water or
glaciers, soils form out of the
Parent Material.
INTRODUCTION TO SOILS FIELD STUDY

HOW SOIL FORMS
Factor 2: Climate
Definition:
The average weather patterns for a region
that occur over a number of years.
Climate factors such as
temperature and amount of
precipitation affect how
biological factors change the
soil, and how nutrients and
minerals are leached through
the soil profile.
INTRODUCTION TO SOILS FIELD STUDY

HOW SOIL FORMS
Factor 3: Topography
Definition:
The slope of the land which can be one of
the things that determines the type of soil that is
formed.
Soils are typically less
developed on hilltops and
hillsides, because soil is
slowly moved by erosion
factors. Soil is deeper and
more developed in low
areas.
INTRODUCTION TO SOILS FIELD STUDY

HOW SOIL FORMS
Factor 4: Biologic Influences
Definition:
Living organisms that influence the
development of the soil and soil profile.
Plants incorporate organic
matter into the soil, and in
some cases change the
chemistry of the soil.
Microbes and insects break
down organic matter and
create pore spaces in soil.
INTRODUCTION TO SOILS FIELD STUDY

HOW SOIL FORMS
Factor 5: Time
Definition:
The amount of time the soil has been
forming.
The length of time the other
soil forming factors have
been in place changing the
nature of the soil is an
important component to how
the soil appears to us today.
INTRODUCTION TO SOILS FIELD STUDY

THE SOIL PROFILE
The 5 Soil Forming Factors combine to make the
soil below us. Every place is a little different,
depending on the specifics of how the 5 soil
forming factors have combined at that specific
place.
INTRODUCTION TO SOILS FIELD STUDY

THE SOIL PROFILE
As soils continue to form they can
develop several distinctive layers
from the top (surface of the
ground) down into the Earth.
When we look at the soil as a
vertical column we call is a “Soil
Profile.”
INTRODUCTION TO SOILS FIELD STUDY

LAYERS OF A SOIL PROFILE
Duff: Duff is made up of leaf
litter and other organic
materials lying on the surface
of the soil (not always present
in a profile).
INTRODUCTION TO SOILS FIELD STUDY

LAYERS OF A SOIL PROFILE
Topsoil: The fertile layer of soil
below the duff layer, and above
the subsoil. The fertile layer that has
organic matter incorporated within
it and contains many nutrients.
INTRODUCTION TO SOILS FIELD STUDY

LAYERS OF A SOIL PROFILE
Subsoil: The layer of soil in a soil
profile that is below the topsoil.
INTRODUCTION TO SOILS FIELD STUDY

LAYERS OF A SOIL PROFILE
Bedrock: A solid layer of rock
beneath some soils (not shown
in this picture).
INTRODUCTION TO SOILS FIELD STUDY