Values, Alterations and Degradation of the Natural Landscape 105
grasslands, wallows etc. exhibiting a significant morphological, geochemical and sedimentary diversity. They are characterized by the presence
of water or by high humidity. They may temporarily dry up during the
summer period, whereas near the end of the winter period they exhibit
their greatest development. They are usually characterized by a significant salinity change in connection with the altitude and the distance from
the shore.
The Mediterranean coastal wetlands constitute ecological unities because
the biocoenoses are not characterized by a mixture of freshwater and sea
water species, but mainly by communities with many species adapted to
this specific environment and endowed with great tolerance to salinity
(euryhaline species). In contrast with the ocean coasts, the tide is negligible
and does not constitute a significant factor for the Mediterranean coastal
ecosystems. This fact, in combination with the light rainfall, hinders the
dilution of the beach lagoons; as a result, ecological habitats with subsaline
or often supersaline waters abound in Mediterranean coasts. Vegetation
as a rule is very rich, but most of the plant species are common. There is a
great variety of fauna, especially birds, that includes many rare species. The
wetlands’ biomass and biological productivity are noteworthy and their
economic significance is considerable. Coastal ecosystems ensure 10–30%
of the total Mediterranean piscatorial production and they host many
aquacultures. Their sensitive location exposes the Mediterranean coastal
wetlands to increased degradation and destruction risks due to the development of tourist facilities, urban and industrial activities, harbour works,
airports and beach roads as well as increased pressures for drainage and
other land improvement works.
Coastal forests and scrubs, as Mediterranean forest ecosystems in general, today cover only a small percentage of their initial geographic extent.
They are mostly ecosystems that have departed from their natural mature
(climax) state due to human intervention over the course of many centuries.
The main factor of change has always been fire, which has significantly
favoured the extension of coniferous forests as well as of scrubs. The pine
(Pinus halepensis and Pinus brutia), kermes-oaks (Quercus coccifera),
lentisks (Pistacia lentiscus), carob-trees (Ceratonia siliqua) etc. are characteristic species of those ecosystems. Cases of advanced degradation are
frequent, and their characteristic is sparse bushes, phrygana and large bare
rocky stretches of land, which generally constitute evidence of repeated
fires and over-grazing.
Mediterranean coastal systems are especially sensitive to the changes
caused by human activity; as a result, today’s Mediterranean coastal
natural environment has become mainly anthropogenic. The great
recess of deciduous or sclerophyllous oak (Quercus sp.) forests during
the last 10,000 years and the expansion of coniferous forests (Pinus sp.)
as well as scrubs that were favoured by human action are characteristic
grasslands, wallows etc. exhibiting a significant morphological, geochemical and sedimentary diversity. They are characterized by the presence
of water or by high humidity. They may temporarily dry up during the
summer period, whereas near the end of the winter period they exhibit
their greatest development. They are usually characterized by a significant salinity change in connection with the altitude and the distance from
the shore.
The Mediterranean coastal wetlands constitute ecological unities because
the biocoenoses are not characterized by a mixture of freshwater and sea
water species, but mainly by communities with many species adapted to
this specific environment and endowed with great tolerance to salinity
(euryhaline species). In contrast with the ocean coasts, the tide is negligible
and does not constitute a significant factor for the Mediterranean coastal
ecosystems. This fact, in combination with the light rainfall, hinders the
dilution of the beach lagoons; as a result, ecological habitats with subsaline
or often supersaline waters abound in Mediterranean coasts. Vegetation
as a rule is very rich, but most of the plant species are common. There is a
great variety of fauna, especially birds, that includes many rare species. The
wetlands’ biomass and biological productivity are noteworthy and their
economic significance is considerable. Coastal ecosystems ensure 10–30%
of the total Mediterranean piscatorial production and they host many
aquacultures. Their sensitive location exposes the Mediterranean coastal
wetlands to increased degradation and destruction risks due to the development of tourist facilities, urban and industrial activities, harbour works,
airports and beach roads as well as increased pressures for drainage and
other land improvement works.
Coastal forests and scrubs, as Mediterranean forest ecosystems in general, today cover only a small percentage of their initial geographic extent.
They are mostly ecosystems that have departed from their natural mature
(climax) state due to human intervention over the course of many centuries.
The main factor of change has always been fire, which has significantly
favoured the extension of coniferous forests as well as of scrubs. The pine
(Pinus halepensis and Pinus brutia), kermes-oaks (Quercus coccifera),
lentisks (Pistacia lentiscus), carob-trees (Ceratonia siliqua) etc. are characteristic species of those ecosystems. Cases of advanced degradation are
frequent, and their characteristic is sparse bushes, phrygana and large bare
rocky stretches of land, which generally constitute evidence of repeated
fires and over-grazing.
Mediterranean coastal systems are especially sensitive to the changes
caused by human activity; as a result, today’s Mediterranean coastal
natural environment has become mainly anthropogenic. The great
recess of deciduous or sclerophyllous oak (Quercus sp.) forests during
the last 10,000 years and the expansion of coniferous forests (Pinus sp.)
as well as scrubs that were favoured by human action are characteristic