Ecologia Mediterranea

N. BOUCHENEB, S.S. BENHOUHOU
The Acacia tortilis subsp raddiana and
Salvadora persica community
This association corresponds to the floristic
group E5 identified by the correspondence
analysis (Figure 4). It is represented by nineteen
relevés taken from large wadi beds and
nearby terraces. The soil has a sandy compact
to gravelly-sandy substrate and altitude ranges
between 930 and 1200 m. The association
was observed in wadi Tehart and in wadi
Ti-n-Amzi (Figure 3). The plant community
encountered in these wadis is part of the Acacia-Panicum
desertic savannah where Salvadora
persica L. is dominant (Table 3).
A detailed analysis of the floristic content of
the relevés makes it clear that this association
is related to the Acacio-Panicion and the Pergulario-Pulicarietea
Quézel 1965 (Table 3).
However, this association does not compare
to any of the associations described by former
workers in the Ahaggar for the Acacia-Panicum
desertic savannah. When comparing the
Cassia aschrek-Panicum turgidum association
with the Acacia tortilis subsp. raddiana-Salvadora
persica community, they show differ-
Table 3 – The Acacia tortilis subsp. raddiana-Salvadora persica association.
74
ent edaphic profile and consequently show a
different species assemblage. The community
described in those particular wadis is characterised
by the original and unique assemblage
of Acacia tortilis subsp. raddiana and Salvadora
persica. The combination of altitudinal
(between 930 and 1250 m), edaphic characteristics
(sandy-gravelly substrate) and wadi
geomorphology (large wadi beds) are the
main physical and environmental factors contributing
to the development of such a distinctive
association. It is therefore proposed
as a new association identified in the Ti-n-
Amzi and Tehart wadis.
The Leptadenia pyrotechnica and
Chrozophora brocchiana community
This association corresponds to the floristic
group E6 identified by the correspondence
analysis (Figure 4). It is represented by nineteen
relevés taken from wadi beds, their tributaries
and outwash zones of the Amaghalghal
and Anefeg wadis, the In-Aha-Guieh
wadi from the Touf Admer massif. Soil varies
Quadrat number 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Area (m²) 200 200 200 200 200 200 200 200 200 200 200 200 200 200
Total cover (%) 20 30 30 30 30 20 30 35 20 20 20 25 15 20
Altitude (m) 980 980 980 930 950 1000 950 1000 1075 1090 1150 1200 1080 910
Number of Taxa 8 6 13 8 9 8 9 8 6 7 9 12 6 9
Caracteristics of the association CP
Acacia tortilis subsp. raddiana 1 2 1 2 2 + 2 3 2 2 2 2 + + V
Salvadora persica 2 2 2 1 1 1 1 1 1 1 1 + + . V
Caracteristics of the Acacio-Panicion Quézel 1965
Zilla spinosa + 1 3 . + . + 1 + 2 + 2 1 1 V
Panicum turgidum + + + + + + + . + . . + + . IV
Acacia ehrenbergiana + . + . + 2 + . . . + + . . III
Senna italica (Cassia aschrek) . . . + . . . + + + . . . . III
Balanites aegyptiaca . . . . . . . 1 . . . + + + III
Maerua crassifolia . . + . . . . . . . + . . . II
Ziziphus lotus . . . . . + . . . . . . . . I
Caracteristics of the Pergulario-Pulicarietea Quézel 1965
Pulicaria crispa . + 1 + . 1 + . . + + + + + IV
Leptadenia pyrotechnica + . . . + + 1 2 . . + 1 . 2 IV
Pergularia tomentosa . . . + . . . . . + + + . + III
Morettia canescens . . + . . . . . + . . . . . II
Heliotropium bacciferum
Psammophils
+ . . . . . . . . . . . . . I
Calotropis procera . . + + + + + + . . + 1 . + IV
Artemisia judaica . . + . . . . . . . . + . . II
Tamarix aphylla . . . . . . . . . . . . . + I
Farsetia ramosissima . . . . + . . . . . . . . . I
Chrozophora brocchiana
Chasmophils
. . 1 . . . . . . . . . . . I
Aerva javanica + + + + + . + + . . . + . + IV
Farsetia aegyptiaca . . + . . . . . . . . . . . I
Deverra scoparia subsp. scoparia . . . . . . . . . + . . . . I
ecologia mediterranea – Vol. 38 (2) – 2012