types of environments resulting from the dynamic equilibrium between
the sea, the river and freshwater can be found in the Baix Ter plain.
The interaction between the sea, the river and the sediments it
carries has given rise to a wide variety of ecosystems, with very
subtle variations in the duration of floods, depth, salinity, nutrient
content or type of substrate. The variety of environments and the
diversity of organisms that can be found in them are two of the
most important ecological aspects of the area. A description of
the main aquatic ecosystems found in the Baix Ter follow.
- marshlands and coastal lagoons.
They are situated in the depression just behind the sand dunes,
an area easily flooded in stormy weather due to its low level and
flat surface. Storms can be followed by rain and floods, so water
flooding the marshes is a mixture, in variable proportions, of freshwater
and seawater. The ground is clayey, little permeable and retains
the salt and water with the consequence that marshland vegetation,
mainly glasswort and reed beds, is adapted to high salinity levels
and periodical flooding.
profile of La Pletera
In lower areas were water is present permanently or nearly permanent,
coastal lagoons with brackish waters, due to seawater penetration,
can be found. These seawater influxes are sudden and short in time.
Evaporation, water drainage and the lack of further water influx
results in an increase in salinity levels; sometimes reaching higher
levels than those found in seawater. La
Pletera is the most extensive marshland found
in the Lower Ter, with Frare Ramón’s’ being the
most characteristic brackish coastal lagoon.
- inland temporary
humanized aquatic atmospheres