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’

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

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

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’

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

Transect lines

Ranging rods

Tape measure

Clinometer to measure angle of slope

Vegetation Surveys Quadrats % occurrence recorded

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?

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?