Biosphere : Sand Dune Succession

Higher Geography Pupil Conference Dalkeith HS 23 rd March 2007 BIOSPHERE Val Vannet High School of Dundee

The Biosphere Sand Dune Succession

Plant Succession
Evolution of plant communities
From pioneer species to climax vegetation
Related to change in the environment
Change brought about by the plants themselves
This change then favours new species
‘ Plants are the architects of their own demise’

Sand Dune Systems
Conditions
Supply of sand
On-shore winds
Colonising plants
Processes
Sand blown landwards
Sand trapped by plants
Plant growth assists dunes to grow
Process repeated on seaward side
Older dunes stop growing
System grows seawards

Tentsmuir :W W2 shore defence These tank traps were at the high water mark in 1940

Seaward growth of the sand dunes at Tentsmuir since 1940

Sample sand dune systems

Tentsmuir

Buddon Ness

St Cyrus

Forvie

Culbin sands

Sand Dune Transect

The Foreshore Blowing sand Salty Dry

Saltwort Fleshy leaves store water Deep tap roots Low growing

Sandwort Waxy leaves

Sea Rocket Fleshy, waxy leaves Tap roots

Frosted orache ‘ Mealy’ leaves are salt repellant Long tap roots

Couch grass Leaves prostrate Withstands modest burial Tolerates salt

Saltwort Frosted orache Couch Grass

Embryo Dunes Scattered foreshore plants Seaweed (humus) On shore winds Sand builds up Highest tide line

Level of built-up sand

Frosted orache Embryo dune

Foredunes Couch grass (salt tolerant) Lyme grass (salt tolerant)

Mobile (yellow) dunes Marram grass

Marram grass
Cannot tolerate salt
‘ Thrives’ on being buried by sand
Inrolled leaves
Long tap roots
Underground rhizomes stabilise dunes

Much bare sand hence ‘yellow’

Ragwort Marram

Less bare sand
More humus
Lower pH
Less Marram
More ‘competitors’

Fixed (grey) dunes Marram more sparse and weaker Other species dominate

Increasing floristic diversity Harebells Bedstraw Restharrow

Parasol mushrooms More humus and soil moisture

Why ‘grey’? Lichens

Marram now very sparse Ground cover almost complete

Dune slacks Main dune ridge Lower relief intersects water table

Phragmites reeds

Rushes

Seasonal slack Rushes Creeping willow

Main dune ridge Slack Dune heath Cotton grass

Final stages of succession Alkaline shell sand Grassland Heathland Acid mineral sand

Dune Scrub (often spinous!) Gorse Buckthorn Dog rose

Sea Buckthorn is well named!

Mixed Woodland Climax

Vegetation Surveys
Transect lines
Ranging rods
Tape measure
Clinometer to measure angle of slope

Vegetation Surveys
Quadrats
% occurrence recorded

Easy ! 100% Marram

Minimum Need-to-Know!
Definition of succession
Definition of climax vegetation
Stages of the succession on sand dunes
One or two named plants for each stage
How are these plants adapted to the environment?

http://www.slideshare.net	82
http://highergeogblog.blogspot.com	67
http://www2.eboard.com	17
http://geodonn.blogspot.com	16
http://www1.eboard.com	13
http://www3.eboard.com	12
http://liversidgeib.wikispaces.com	6
http://geodonn.blogspot.co.uk	6
http://www.icurl.net	4
http://www.highergeogblog.blogspot.com	4
http://www4.eboard.com	1
http://www.geodonn.blogspot.com	1

Biosphere : Sand Dune Succession

by ValVannet on Mar 24, 2007

Accessibility

Categories

Tags

Upload Details

Usage Rights

12 Embeds 229

Statistics

Biosphere : Sand Dune Succession — Presentation Transcript