skills day-sand dunes-lesson 1

Report
Welcome to the A’ Level
Geographical Fieldwork and Skills Day
Preparing you for the Unit 2 & Unit 4A
examinations fieldwork investigation questions
What do you need to know…?
The Unit 2 paper will have a fieldwork question
worth 25 marks where you have to draw upon
fieldwork you have experienced as part of your
Geography course. You could be asked about one
or more of the following:
•
•
•
•
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Purpose – Aims / Hypotheses / Location / Theoretical background.
Data collection & Sampling Techniques.
Data presentation & Statistical Techniques.
Analysis and conclusion.
Risk assessment.
The same foci are used for the Unit 4a
st
What do you need to know…?
Unit 4A is a more challenging examination than the AS
equivalent Unit 2. The questions have to demonstrate
elements of both synopticity and stretch and challenge.
Essentially, the differences between the two
examinations can be summarised as:
- Unit 2 — assesses what I did on my fieldwork
- Unit 4A — assesses why I did what I did on my
fieldwork
• Hence, all questions in Unit 4A will be evaluative (though
can expect one or two for Unit 2). It is suggested that
there is a limited range of questions that could be asked.
The table below summarises a range of possible
questions.
What do you need to know…?
POA, Today!
• Lesson 1: Purpose of the fieldwork investigation
• Lesson 2: Methods of data collection, sampling
techniques & risk assessment
• Lesson 3: Data presentations & statistical tests
• Lesson 4: Data analysis & evaluation
• Lesson 5: Geographical skills – Basic statistical
& graphical skills
Aim:
How and why does vegetation change across a
psammosere at Llobregat delta, Barcelona?
Purpose of the investigation:
Aims, Hypotheses, Location & Theory
Aim – what it it? / Click to reveal
Where is the Llobregat Delta?
S.W. of Barcelona / Discuss justification for location – provide excellent example of zonation and succession + influence of winds (blow outs) +poss human
intereference in formation of Psammosere (recreation & trampling) + plagio climax (pine trees)– students note 1st page
What is the ‘textbook’ theory of
psammosere succession?
Theoretical background
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Expectations:
High wind and high pH values to develop the embryo dune.
Grasses such as lyme grass and sea couch grass then appear.
A humus layer builds up which traps both water and nutrients.
Marram grass is the most common species.
Vegetation reaches 100%.
Sand sedge and sea spurge start to dominate and small shrubs
appear for the first time.
Shelter from winds and a true soil begins to develop.
Dune slacks.
Climatic climax vegetation is reached at the mature dune.
Develops a soil which can support shrubs and trees.
Debrief from their sheets and show / see end of teacher pack
A transect across a sand dune system
The transect above has hidden ‘hotspots’. Move your mouse over the
diagram and these will be revealed. Progress across the transect using
these hot spots.
You can return to this diagram at any time by using the return button
You can advance quickly from one slide to the next by using this
button
You can go from this slide to the revision materials by using this
button
Embryo and Fore Dunes: the environment
Click on photo to reveal annotations
on-shore winds
high water
mark
poor water
retention
sand builds up
against pioneer
plants
seaweed
deposits
humus
transient dunes
pH 7
%OM 0.1
sand alkaline
Embryo and Fore Dunes: the plants
The plants which grow here have
adaptations which allow them to
grow in a difficult environment :
• waxy leaves to retain moisture
and withstand winds
• prostrate (low) habit
to avoid strong winds
• deep tap roots to obtain
available moisture
Sandwort
Frosted orache
• high salt tolerance
Saltwort
Sea rocket
Sea couch
Yellow Dunes: the environment
Click on photo to reveal annotations
above the
level of high
tides
reduced wind
speeds
pH 6.5
%OM 0.23
‘Soil’ slightly
less alkaline and
more water
retentive
Some humus
forming
Surface continually
blown away and
replenished with
fresh sand
Yellow Dunes: the plants
The dominant plant species is
Marram grass:
• Salt tolerant
• Thrives on being buried by sand
• Inrolled leaves to reduce moisture
loss
• Long tap roots
• Underground rhizomes stabilise
the sand
Other plants such as Ragwort, Red
fescue and Sand sedge begin to
appear
Grey Dunes: the environment
Click on photo to reveal annotations
sheltered by higher,
seaward dunes
lower pH
little mobile
sand
pH 5 - 6
%OM 1.0
sand no longer
accumulating
higher humus
content
a more closed vegetation
community in which marram
grass is no longer able to
compete
Grey Dunes: the plants
• higher species diversity
• mainly perennials
• marram becomes more
sparse
• surface lichens give ‘grey’
appearance
Older grey dunes may have extensive
covering of lichens and heather
Dune Slacks: the environment
Click on photo to reveal annotations
occur in low lying hollows
between dune ridges
soil acidic
pH 4 - 5
%OM 8.5
water table high –
especially in winter
relief
intersects
the water
table
Dune Slacks: the plants
The community which develops here comprises moisture-loving
plants commonly found in many fresh water wetland areas e.g.
Flag iris
rushes
Phragmites reeds
Bog cotton
Dune Heath/Woodland: the
environment
Click on photo to reveal annotations
well sheltered
from winds
maritime influence
is minimal
acidic soil
nutrient rich
pH 4
% OM 12.1
soil has high organic
matter content
Dune Heath / Woodland: the plants
Human interference means that true
mixed woodland climax vegetation is rarely
seen on dune systems in the UK
Most dune systems develop into a
community of heathland, woody perennials
(often spinous) and scattered trees.
Heather
Revision
materials
Heather
Sea buckthorn
Psammosere: summary of stages
Theoretical background
Theoretical thump-up!
Question 1
Question 5
Question 9
Question 2
Question 6
Question 10
Question 3
Question 7
Question 11
Question 4
Question 8
Question 12
Starter lesson 4
For any Geography fieldwork study you have undertaken:
Describe the purpose of the investigation
You have only………..
For any Geography fieldwork study you have undertaken:
Describe the purpose of the investigation
For any Geography fieldwork study you have undertaken:
Describe the purpose of the investigation
For any Geography fieldwork study you have undertaken:
Describe the purpose of the investigation
What are other likely opening questions
at AS Level?
What are other likely opening questions
at A2 Level?

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