Environmental Engineering Reference
In-Depth Information
Table 6.3
Plant lifeforms (as a percentage of total) in the mountain areas of Greece
Annual-
Woody-
biennial
Perennial
suffruticose
Geophytes
Grass-like
Spiny
Crete
17.8
56.2
14.7
8.8
7.8
5
Peloponissos
11.3
64.4
12
9.1
9.4
4.4
Sterea Ellas
11.7
64.6
11.3
8.5
9.5
3.6
S. Pindos
11.5
65
10.5
6.7
11.8
3.3
N. Pindos
10.8
65.6
10
6.9
11.8
2.7
E. Central
12.6
62.9
11.5
8.6
9.7
3.2
North Central
10.5
65.5
10.2
7.1
11.4
2.2
North East
9.3
64.4
13.8
7.5
10.2
2.2
Reproduced from Strid (1993).
6.3 Flora
Phytogeographically there are many elements other than Mediterranean ones (see
Table 6.1) in the flora of the mountains in the Basin. For examples, the Pyrenees are
in a transition area between Central and Mediterranean Europe and contain a small
Mediterranean phytogeographical unit mainly in the south and east of the main
axis of the Cordillera (Davis
et al.,
1999). In Greece the Mediterranean element
reaches its peak in the mountains of the Central East, followed by the massifs in
the Peloponnese and Crete (Table 6.1). The Dinaric Alps contain a range of alpine
continental and Mediterranean species but also species of boreal origin (Tvrtkovi¸
and Veen, 2006). The presence of a high number of endemic species in the Baetic
ranges of Spain resulted in the area being recognized as a distinct biogeographical
unit (Mota
et al.,
2002). The Baetic and sub-Baetic Mountains share many species
with the mountains of North Africa. Although the rule of thumb suggests that the
flora of the Mediterranean mountains does not display high overall species richness
(Medail and Verlaque, 1997) there are a few exceptions. The flora of the Rif moun-
tains of north Africa exceeds 2000 species per 15 000 km
2
(Moore
et al.,
1998)
whereas the Greek mountain flora (above 1500 m) comprises 1600 species (Strid,
1986; Strid and Tan, 1991).
Many mountain species in the Mediterranean have evolved from lowland species
as a result of ecotypic differentiation on an altitudinal gradient combined with ge-
ographical and/or ecological differentiation (Strid, 1985). For example, the flora of
the Cretan mountains comprises relict species, many of which are endemic deriva-
tives of lowland species and species that also occur in the continental Greek moun-
tains such as
Scutellaria hirta
from
Scutellaria sieberi
and
Bellis longifolia
from
Bellis sylvestris
(Greuter, 1972). A large number of lowland species reach the al-
titudinal zone between 1000 and 1500 m. Some species such as
Euphorbia acan-
thothamnos, Verbascum spinosum
and
Arum creticum
can survive in the high moun-
tain tops above 2000 m without being modified.
