Sand dunes Flashcards
what are the optimum conditions for the formation of sand dunes?
- sufficient flat land available to accommodate the dunes
- strong onshore winds
- plentiful supplies of sand
- vegetation to colonise the dunes
- the beach ideally has a low gradient and a high tidal range
the first larger dunes to establish themselves at the top end of beach are known as
embryo dunes
in embryo dunes what are the pionese species which take route
sea rocket
sea couch
saltwart
what are the threats to dune systems?
over grazing
recreation is a major land use
seal level change due to global warming, leading to an isostatic increase in sea levels
afforestation
why is it important to manage sand dunes?
sand dunes are an effective natural sea defence
disturbance of sand dunes may destabalise their fragile equilibrium and natural habitat
action taken to safeguard sand dunes from degradation can take a number of forms including:
- cordoning off areas that are particularly sensitive and and restricting public access
- the transforming of potentially biodiverse stretches of dunes into nature reserves
- the building of boardwalks through dunes to be used rather than informal footpaths
- the stabalisation of dunes by planting successful species on dune ridges
- grazing livestock
- giving tourists information about potential damage
what are aeolian processes
the action of the wind
what are the order of sand dunes
embryo
yellow dune
grey dune
wasting dune
what are the environmental conditions at like at the embryo dune?
high ph
colder near sea
stronger winds
may be immersed in water
what are the environmental conditions like at the wasting dune?
lower ph
warmer
more sheltered
easier to access water table
does the amount of vegetation increase as you go in land?
yes
does the number of species increase as you go in land
yes
