Environmental Engineering Reference
In-Depth Information
Table 2.4 Examples of late Quaternary vegetation change
Date
Characteristics
Date
Characteristics
Site: Tigalmamine, Morocco, 1626m asl
(Lamb et al., 1989)
Site: Aammiq, Bekaa Valley, Lebanon,
865m asl (Hajar et al., 2008)
450
Increase in Cedrus
atlantica
3400-1000
Evergreen and
deciduous oaks
with cedars
2250
Human impact: forest
degradation
6100-3400
Sedimentary process
disturbed;
aridity/human?
4000
Cedrus atlantica
arrives
11 500-6100
Open oak forest
locally with cedars
on Barouk Mt
8500
Oak ( Quercus ) forest
develops
By 11 000
Aammiq marsh
develops
12 000-8500
Herb-rich grassland
predominates
12 000-11 000
Chenopodiaceae
steppe with
scattered cedars
14 000-12 000
Scattered oaks invade
grassland
pre-12 200
Expansion of cedars
and deciduous oaks
18 000-14 000
Herb-rich grassland
predominates
Middle Atlas Mountains of Morocco and shows that herb-rich grassland was re-
placed with oak forest, with cedar being a relatively late invader. At Siles (see Ta-
ble 2.2), at 1320m asl in the Segura Mountains of Spain, pine spread into early
Holocene grassland rather than oak and there is no evidence for cedar, which was
confined to the southern and eastern parts of the Mediterranean Basin. Indeed there
is evidence for the presence of cedar ( Cedrus libani ) in the Aammiq wetland, Bekaa
valley, pre-12 200 years BP as shown in Table 2.4. Here in the surrounding moun-
tains oak forests and cedars dominate the Holocene.
During the later Holocene, post-5000 years BP, human impact is evident through-
out the region. Its toll on forests plus natural processes of aridization resulted in
forest fragmentation and the dominance of shrubs, which are typical of the region
today. The rise and fall of many of the world's great civilizations caused vegeta-
tion change and shaped the land to create anthropogenic landscapes that are today
occupied by some 450 million people.
2.5 Conclusion
The Quaternary (and earlier) history of the Mediterranean mountains and the
Mediterranean Basin in general is complex. Evidence derives from a variety of
 
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