Transcript Biosphere Power Point

Biosphere ~ What We’ll Learn
Soils
Plant
Sand
Dunes
Succession
Soils ~ What We’ll Learn
• What goes in and out of a soil
• What is a soil profile &
describing soils from profiles.
• Explain how the following soils develop;
a) Gley Soils
b) Podsol Soils
c) Brown Earth Soils
Soil Development ~ Pedogenesis
Vegetation
Drainage
Relief
Climate
Soil
Development
Bedrock
Biota
In groups of four, each member must
read up on one of the inputs that affect
soil development.
Next everyone must report back to the
rest of the group what they found out.
Then answer Task 1 Questions 2,3,4 & 5.
Soil Horizons & Profiles
Soil Profiles are
vertical cross
Soil
Horizons
are
the
sections
of the
soil
different
sections
taken from
the or
distinctive
surface to layers
the
found within
soil,
bedrock
of thea soil.
these help
characterise the soil.
Ao Horizon
Surface
A Horizon
B Horizon
C Horizon
Bedrock
Soil Horizons
Al
Af
AoBHorizon
The
Horizon is called the sub soil
and has organic material in its top
Ah
part and broken rock in its bottom
A Horizon
The
Ao
&A
Horizons are referred
part.
darkerisbrown
it is
the
The The
C Horizon
the bottom
toofas
thebed
top
soil. Dead leaves form
more
leaching
that has
taken
place.
part
and consists
the
the Al
horizon, which, as they
rock or parent material,
some
decompose
form the Af
of which is dislodged into
the
(fermentation)
horizon. When they
B Horizon by freeze-thaw
or
have decomposed, they form a rich
biological weathering.
humus layer called the Ah horizon,
which mixes in with the A horizon.
C Horizon
Gley Soils – Tundra (Alaska)
Ao
Light Brown
A
Black
B
Blue/Grey
C
Bedrock
Gley Soils
Ao
Ao
Light
LightBrown
Brown
The top layer is poor in nutrients reflecting the
A
Black
vegetation above it being grasses, lichens, mosses
and rushes.
The A horizon is a thick layerBlue/Grey
of black
Blue/Grey
BB
humus,
due to the slow decomposition of
the leaf litter in such very cold conditions,
C
C
B horizonbyisfreeze-thaw
a blue/grey layer
The C horizonThe
is affected
weathering
the lack
of O2which
in therise
soilup into
and produces due
manytoangular
blocks
by through
waterlogging
the soil
the caused
B horizon
frostof
heave.
Gley Soils
Ao
A
B
C
When the soil does
dry out air gets
into the soil and
re-oxidises the
soil minerals so
that iron oxide can
be found along
roots and as spots
in the soil as air
pores.
Gley Soils
Ao
A
B
C
When the soil does
dry out air gets
into the soil and
re-oxidises the
soil minerals so
that iron oxide can
be found along
roots and as spots
in the soil as air
pores.
Podsol Soils Taiga (Norway) or Scottish Highlands
Ao
A
B
Black
Ash/Grey
Orange Iron Pan
Reddish brown
C
Bedrock
Podsol Soils
Ao
Ao
Black
Black
A
A
There is a large black Ao horizon
Ash/Grey
Ash/Grey
made up of rotting vegetation which
is
slow to break down due to the acidity
of the vegetation pine trees &
The A horizon is ash grey as most of the nutrients,
heather.
Iron, from this horizon have been leached into the B
horizon, this is called eluviation. The leaching occurs
because there is a high precipitation, but a low
evaporation as a result of the cold temperatures.
Podsol Soils
Orange Iron Pan
B
Reddish brown
In the B Horizon nutrients are being leached into it giving a
more fertile soil, reddish brown in colour. When the nutriemt
rich water drains into this horizon it is called illuviation. If
there is a lot of iron being deposited it can form a an iron rich
layer called an iron pan. This is impermeable and so stops
further drainage, meaning that the soil above it can water log
and turn into a gley as oxygen is lost.
Podsol Soils
The C Horizon can produce some angular rocks from freezethaw depending if it is cold enough. The horizons in general are
well defined due to the lack of biota in these cold areas and
there is less frost heave mixing them up.
C
Bedrock
Brown Earth Soils S.E. England
Ao
A
B
C
Green Brown
Dark Brown
Brown
Bedrock
Brown Earth Soils
Ao
Ao
Green
Green Brown
Brown
These soils develop beneath broadleaved
woodlands
with a variety of plants,
so the
A
Dark
A
Dark Brown
Brown
vegetation generally gives a nutrient rich and
mildly acidic humus, a Mull Humus. This means
that more biota can also live in the soil.
The A Horizon is a dark brown colour due to the many
nutrients from the plants and from the biota which help move
the humus about. The biota are numerous due to the warm
climate and there are many bacteria as precipitation rates are
lower than evaporation rates.
Brown Earth Soils
B
Brown
The B horizon is also quite rich in nutrients, this is
not down to leaching but to biota moving the
nutrients down, though it is lighter than the A
horizon as less humus is brought down generally.
Brown Earth Soils
C
Bedrock
The C horizon has tree roots penetrating the bedrock and
adding rock to the soil and some chemical weathering of the
soil may also take place due to the warm climate with some
moisture.
Overall the horizons are well mixed and blurred because biota
move between the horizons mixing them up.
Plant Succession
Ecosystems
The Stages Of
Plant Succession
Ecosystems
Organisms
Life Cycles
Environments
Variety Of Sizes
Ponds ~ Deserts
Ecosystems
These are systems in, which plants, ____________,
insects & micro-organisms interact within a natural
environment consisting of climate, rock & _____.
They can be small areas such as life around
________ or larger areas such as whole deserts; and
depend on energy from the sun, which plants use to
create _______. The death of these plants, add
nutrients to the ground, which are then
_____________ into the soil to help plants grow.
The eating of plants by animals and their subsequent
recycling of the soil through __________ also help
to maintain the system.
Ecosystems
These are systems in, which plants, animals, insects &
micro-organisms interact within a natural
environment consisting of climate, rock & soil .
They can be small areas such as life around ponds or
larger areas such as whole deserts; and depend on
energy from the sun, which plants use to create food .
The death of these plants, add nutrients to the
ground, which are then recycled into the soil to help
plants grow.
The eating of plants by animals and their subsequent
recycling of the soil through manure also help to
maintain the system.
Plant Succession
First Stage
Bare
Earth
Stage
Pioneer
Building
Stage
Stage
Climax Stage
Last Stage
Plant Succession
Key Points
•Humus content
•Water content
•Root development
•Height of plants
All increase over
time and with the
death of plants
Plant Succession
Task 9
Question 2 – 8
Read the Core Higher text
book pages 148 to 149 answer
these questions.
Plant Succession
Climax Vegetation
This is the last of the 4 stages of plant
succession,
this is how plant communities
develop over time. In
this stage the ecosystem is in balanceand so no new
plant species take root, justthe continuation of
existing species. This is because physical factors
such as climate andsoil are fully developed so they
enough to affect plant
will not change significantly
development. Typical plants from
this stage include
oaks.
Sand Dune Succession
Parts Of A Sand Dune
Plants On Sand Dunes
Evolution Of Sand Dunes
Sand Dune Succession
For Task 10 Qu.1 read the strips of paper
describing the different parts of sand
dune succession and then, only after your
teacher has checked them with you, write
them into your workbook.
Strandline
Yellow Dunes
Embryo
Fore Dunes
Dunes
Water Table
Mature Dunes
Grey Dunes
Dune Slack
Sand Dune Succession
Task 10 Qu. 2
Strandline
Embryo &
Fore Dunes
Orache
Orache
The strandline
has a frosted
is where
coating
a range of detritus is
which
washed
helps
up protects
on the beach
it from
including seaweed,
the
driftwood
salt in &
the
shells;
sea as
containing
well as enough water &
organic
helping
debris
reduce
to allow
dessication
the germination of wind and
seas
(shredding)
borne plants
of its
such
leaves
as orache
by
& saltwort. The
first of these
wind blown
plantssand.
help to trap sand behind them
forming dunes and the opportunity for rooting to &
humus to develop.
Strandline
Embryo &
Fore Dunes
Saltwort
Both
orache
saltwort
havewhich
deep roots
Saltwort
has&fleshy
leaves,
help which help to
anchor
them
in thethis
sand,
but more importantly
help to
to store
water,
is important
as
access
fresh
water deep
sand. They also have
there
is shortage
of below
fresh the
water
long
lateral
roots
which
spreadthrough
just below the surface
which
drains
away
so easily
of the sand to catch
any rainwater, which drains rapidly.
the sand.
Strandline
Embryo &
Fore Dunes
The orache & saltwort provide shelter for plants like
sand couch to grow at the the fore dunes. This is due to
the development of humus from dead orache/saltwort &
the consequent build up of moisture.
Yellow Dunes
Dominated by
marram grass
Named after the
colour of the sand
which is blown by
the wind
Yellow Dunes
Marram Grass
Itquickly,
has 2 types of roots,
The stemMarram
of marram
alsograss
growsisvery
some penetrate
to a
tightly wrapped
up to 1mround
a year,
likewhich
a
means
it
very deep depth and
pine needle,
won’tthis
be covered
reducesby developing
some
spread laterally
evapo-transpiration
sand dunes created
and so by the
wind.
under the sand to
preserves water, remember it
collect rain water from
is a dry environment.
far off points.
Grey Dunes
Grey dunes get their name from the mixing
of sand (yellow) with humus (black). The
humus build up has resulted from the decay
of marram etc. and adds nutrients and water
to the soil. This means more plants are able
to survive here than on previous sections e.g.
heather, chickweed & dandelions.
Dune Slack
Between the dunes are hollows, some of
which, can be damp where water gathers,
called slacks. These occur when the hollow
dips into the water table and plants such as
rushes and alder can be found there; these
can tolerate the very wet conditions.
Mature Dunes
These dunes rarely appear in
Scotland, but have the highest
humus, water and plant content of
any of the dune zones. Essentially
they are the climax vegetation of
the dune world. They are typified by
trees such as the Scots Pine.
Strandline
Embryo
Dunes
Sea Rocket