biological diversity and tropical forests in tunisia - PART

Vegetation Characteristics of Special Importance
The Zembra archipelago is the only island location of the Olea-
lentiscus association in Tunisia. Insularity has resulted in the
halophile vegetation formation being different from that same type
elsewhere. The littoral eone has been left undamaged by man for many
years and the halophile vegetation ie therefore a prfme example of its
typa in Tunisia. Soma species on Zembra are also common in Italy, but
. have not extended their range into mainland Afrfca. These include:
Senecio cinerea
Echium maritimum
Iberfs semperf lorens
Poterkum spPnosum
(Sanguisorba spinosum)
The ocly Tunisian location of Calendula suffruticosa is Zembra. Rare and
endemic species include (~aulthier 1978, IUCN 1987, Radford and Peterken
1969):
T Scabiosa farinosa (cap Bon only)
rT Diarthus rupicola hemaensis (cap Bon only)
r Avena longiglumis
r Meliotus alegans
T Melica minuta ssp euminuta
NA Ferula ticgitana (cap Bon and Oran, ~lgersa)
r Silene neglecta
r Erodium hymenoides
v Sisymbrium polyceratum
v Brassica cretica atlantica
r E. maritimum
r Lavatera punctata
TA Sedam tuberosam
...................................................
v = Very Rare NA = North African Endemic
r = Rare TA = ~unisia/~l~eria Ecdemic
T = Tunisia Endemic
B. Fauna
Mammals. Askde from small rodents and bats, the only mammal on the
island that is probably native is the Maghreb subspecies of the European
rabbit. In areas where rabbits congregate, they can virtually eliminate
Brassica cretica and Daucus carotta by grazing. Myomatosis drastically
reduced the rabbit population in the past, but in 1977 Snane still
estimated 10 rabbits per hectare near-Cappo Crosso and 3 per ha around
Calla Freda and Air Kabar.
Introduced species include abundant black rats Rattus rattus
alexandrus, which are preyed upon by feral cats. Some European mouflon
- Ovis musimon were introduced to the island, as well as feral goats and
sheep, which are now causing overgrazing and soil compaction problems -
especially the goats.
Endangered monk seals were observed on the Zembra coast in the past
(IUCN 19871, but there have been no reports in recent years. Commoc
dolphics are often observed near the coast.
-
Birds. Of the 140 bird species recorded for the Zembra archipelago,
most are migratory. Some species stop at the islands for ocly a few days
while others remain most of the year. The lack of a dense herb layer
under the shmb formations results in a lack of nesting cover acd a lox
prodaction of icsects for insectivores to prey oc (~nane 1977). Both