12
H.-J. Bolle
events are governed by smaller time-scale systems than those of the temperature.
Between the eastern and western part of the Mediterranean exists an anti-phase
relationship which can be attributed to blocking situations over the Atlantic Ocean.
Strong Atlantic blocking accompanied by frequent depressions result in positive
temperature anomalies in the east and negative in the west and vice versa.
The temporal variability of Mediterranean climate will be discussed in
connection with trend analysis in section 6 with special emphasis on the
hydrological regime.
2.3 Vegetation and Soils
Mediterranean woodlands are dominated by evergreen hardwood forest termed
sclerophyllforest. Its major species are holm oak (Quercus ilex), cork oak (Quercus
suber), Aleppo pine (Pinus halipensis), stone pine (Pinus pinea), black pine (Pinus
nigra) and olive trees (Olea europaea). The olive appeared as a wild species after
10.000 BP and are widely grown since about 4.000 BP. In addition Eucalyptus
grows in coastal areas.
Where the forests were destroyed either to obtain construction and burning
materials or by wildfires, sparse to dense scrub (low macchie) regrows, termed
maquis or macchia (Spanish monte bajo, in Greek Xerovumi). Most of the low
maquis species root easily along cracks and layer surfaces and regenerate by root
suckers which make its distribution less vulnerable by fires. Under favourable
conditions holm oaks and a wealth of other plants (see e.g. Paccalet, 1981) regrow,
forming the high macchie. Forest may regrow, but sometimes with different species,
if the climatic and soil conditions are favourable and if there is no further
intervention for a longer time period.
Under less favourable conditions on calcareous soils the vegetation may degrade
to garrigue, Spanish matorral or tomillares which is characterized by less dense and
lower vegetation. "Dwarf forest", chaparral, may develop. Heath species (Ericaceae:
Erica arborea - tree heath, erica multiflora) are often found on degraded soils. In
its extreme, the Spanish matorral vegetation sometimes covers only 2-4% of the
surface (Albaladejo, 1995). Major species are rosemary (Rosmarinus officialis),
specific gras species (Stipa tenacissima), sun-roses (Helianthemum pilosum), clover
(Anthyllis citisoides), mastix (Pistacia lentiscus), broom (Genista acanthoclada),
Juniperus phoenicea, Thymelaeaceae (in dry areas), Cistus monspeliensis and
salvifolius, Smilex aspera, Lonicera etrusca, Opuntia ficus-indica, Ph illy rea
angustifolia (not in Greece) and many other species. Garrigue is resistant against
arid conditions but during hot and dry periods the leaf area index and weight
decreases.
The vegetation-climate relationship can most evidently be studied Turkey
(Atalay, 2001). At the climate climax after the last glaciation the vegetation was
governed by Pinus brutia (red pine) in the lower belt, and Pinus nigra (black pine),
Cedrus libani (cedar), and Abies cilicica (Taurus fir) in the higher regions. The
lower belt starts at the coast with around 800 mm precipitation and reaches up to
H.-J. Bolle
events are governed by smaller time-scale systems than those of the temperature.
Between the eastern and western part of the Mediterranean exists an anti-phase
relationship which can be attributed to blocking situations over the Atlantic Ocean.
Strong Atlantic blocking accompanied by frequent depressions result in positive
temperature anomalies in the east and negative in the west and vice versa.
The temporal variability of Mediterranean climate will be discussed in
connection with trend analysis in section 6 with special emphasis on the
hydrological regime.
2.3 Vegetation and Soils
Mediterranean woodlands are dominated by evergreen hardwood forest termed
sclerophyllforest. Its major species are holm oak (Quercus ilex), cork oak (Quercus
suber), Aleppo pine (Pinus halipensis), stone pine (Pinus pinea), black pine (Pinus
nigra) and olive trees (Olea europaea). The olive appeared as a wild species after
10.000 BP and are widely grown since about 4.000 BP. In addition Eucalyptus
grows in coastal areas.
Where the forests were destroyed either to obtain construction and burning
materials or by wildfires, sparse to dense scrub (low macchie) regrows, termed
maquis or macchia (Spanish monte bajo, in Greek Xerovumi). Most of the low
maquis species root easily along cracks and layer surfaces and regenerate by root
suckers which make its distribution less vulnerable by fires. Under favourable
conditions holm oaks and a wealth of other plants (see e.g. Paccalet, 1981) regrow,
forming the high macchie. Forest may regrow, but sometimes with different species,
if the climatic and soil conditions are favourable and if there is no further
intervention for a longer time period.
Under less favourable conditions on calcareous soils the vegetation may degrade
to garrigue, Spanish matorral or tomillares which is characterized by less dense and
lower vegetation. "Dwarf forest", chaparral, may develop. Heath species (Ericaceae:
Erica arborea - tree heath, erica multiflora) are often found on degraded soils. In
its extreme, the Spanish matorral vegetation sometimes covers only 2-4% of the
surface (Albaladejo, 1995). Major species are rosemary (Rosmarinus officialis),
specific gras species (Stipa tenacissima), sun-roses (Helianthemum pilosum), clover
(Anthyllis citisoides), mastix (Pistacia lentiscus), broom (Genista acanthoclada),
Juniperus phoenicea, Thymelaeaceae (in dry areas), Cistus monspeliensis and
salvifolius, Smilex aspera, Lonicera etrusca, Opuntia ficus-indica, Ph illy rea
angustifolia (not in Greece) and many other species. Garrigue is resistant against
arid conditions but during hot and dry periods the leaf area index and weight
decreases.
The vegetation-climate relationship can most evidently be studied Turkey
(Atalay, 2001). At the climate climax after the last glaciation the vegetation was
governed by Pinus brutia (red pine) in the lower belt, and Pinus nigra (black pine),
Cedrus libani (cedar), and Abies cilicica (Taurus fir) in the higher regions. The
lower belt starts at the coast with around 800 mm precipitation and reaches up to