biological diversity and tropical forests in tunisia - PART

H. Pinus halipecsis (aleppo pine)
Aleppo pine is the forest tree with the largest area ic Tucisia. It
grows across the count-y, but is most comnoc ic the Tanisiac Dorsal
mo&ctaics where the ancual rajcfall is 400 - 600 mm acd the bioclimate is
Semi-arid or Arid. Conditions are most favorable near Kaaserice, and ic
the High Tell rear Le Kef. The present area covered is only one-fourth of
the catu-a1 racge of aleppo pine. Most of the reduction is due to human
pressure for fuelwood, timber, agricultural land acd grazicg areas. Ir
the cortheastex pa-t of its Facge, aleppo pine oftee grows in associatioc
with Erica miiltiflora.
-
I. Cupressus sempe-yirecs f. cumj dice (~aktar cypress) Groves
Yaktar cypress is corsidered endemic to Tucisia, but the-e are some
do.;Sts ~egardicg its txie o-igic. There are only three small natural
stards growicg ic the Kesse-a fo-est of the Tucisiac Do-sal mo~ntaic
rarge, b-t it has been widely planted in windb~eaks.
- Other forest species include ash Fraxin~s ac~ustifolia, elm Ulmus
cam~estris, alder Alcus glaticosa and aspen Populas alba acd P. nigra.
These species a-e connonly foacd along rivers in associatioc with pice or
oak fo-ests. Small stards of rare Moctpelie- maple mocs~essulanum
grow at the surmits of Djebel Zaghouac, Dj.
Turisier Do~sal.
Bargou acd Dj. Serdj ic the
Deg-aded forests are oftec vegetated by maquis of shrubs ard low
trees. Ic the north, heather Erica sp. forms a fairly lazge p-oportioc of
the understory of cork oak forests. Vhec the oak is removed a maquis of
heathe: yenairs acd icc-eases ic decsity. A commoc maqcis association on
hot expositiocs ic s~bhomid to arid biocfimates is characterized by:
Olea europaea (wild olive) Pistacia lentiscus
Ce-atocia siliqua ( carob) Jasmicum frdticacs
Wild olive and ca-ob are catego-ized as Nediterraneac elemerts ( ~ l
Han-ouri 1978) with tropical affinities (~e~erimhoff 1941). The
associatior. is f o ~ ~ ir d Sabhumid to Arid bioclimates where the yearly
raicfall is from 200 to 800 m.
Degraded aleppo pice fo-ests ofter. sapport a maq~is of Juciperus
oxycedxs ard - J. phoe~jcja or. high slopes and summits OF rosemayy
Rosna-lr,s offjcjcalis or the slopes and 1owlar.d~. There are c.300,000 ha
of rosena-y maq~is ir T~risia, ofte~ mjxed with other forest associatiocs.