Saccharum ravennae

Rouissi, Alaeddine, Ezzine, Olfa, Yangui, Islem, Nouainia, Walid, Zouaoui, Refa & Ammari, Youssef, 2024, Phytoecological study of a Biosphere Reserve in arid climate in Tunisia, Caldasia 46 (1), pp. 59-70 : 65-66

Saccharum ravennae (L.) H.Scholz

Stipa capensis Thunb.

Stipa tenacissima L. 2.325 0 0

13.953 0 0

4.651 0 0

2.325 0 0

32.558 0 28.571

Stipagrostis (= Aristida ) adscensionis L. 16.279 0 21.428 (Continued)

Relative frequency (%) Family Species BBh. Ha. Co.

Stipagrostis obtusa Nees

Stipagrostis pengens (Desf.) De Winter

Stipagrostis ciliate (Desf.) De Winter

Tricholaena teneriffae (L.f.) Link

Tetrapogon villosus Desf.

Polygonaceae Polygonum equisetiforme Sibth. & Sm.

Primulaceae Coris monspeliensis L.

Pteridaceae Adiantum capillus-veneris L.

Rhamnus lycioides L.

Rhamnaceae

Ziziphus lotus (L.) Lam.

Rutaceae Ruta chalepensis L.

Scrophulariaceae Anarrhinum brevifolium (Coss. & Kralik)

Solanaceae Lycium arabicum Schweinf. ex Boiss

Tamarix africana Poir.

Tamaricaceae

Tamarix gallica L.

Thymelaeaceae Thymelaea sempervirens Murb.

Urticaceae Forsskaolea tenacissima L.

Fagonia glutinosa Delile

Fagonia cretica L.

Zygophyllaceae

Nitraria retusa Asch.

Zygophyllum album L.f.

20.930 11.111 28.571

2.325 0 0

18.604 0 0

9.302 0 0

6.976 0 0

6.976 0 0

4.651 0 0

4.651 0 0

2.325 0 0

9.302 11.111 0

2.325 0 0

4.651 0 0

11.627 11.111 7.142

2.325 0 0

2.325 0 0

4.651 0 0

2.325 0 7.142

4.651 55.555 0

9.302 0 28.571

6.976 0 0

2.325 0 0

Species richness 115 109 23 41

The a and B diversity among zones of the Biosphere Reserve of BouHedma

The Jaccard index ( B diversity) varied between 0.189 and 0.316 (Table 3). Statistical analysis showed a non-signifi- cant difference of H and D indexes among the three zones with ( F (2, 63) =2.629, P =0.08) and ( F (2, 63) =3.022, P =0.056), respectively. Nevertheless, Pielou evenness index was significant ( F (2, 63) =4.127, P =0.021). For the a diversity, the BBh. zone was the most diverse showing a Shannon and Weaver index of 3.922 bits, a Simpson diversity index of 0.970 and a Pielou evenness index of 0.836. However, the least diverse was Ha. with 2.190, 0.706 and 0.811, respectively (Table 3). A highly significant Pearson’s correlation coefficient was observed between species richness and altitude ( R 2 = 0.36, p=0.003), while it was significant between species richness and longitude ( R 2 = 0.58, p=0.037) .