Floristic composition and vegetation analysis in Hail Region North of Central Saudi Arabia

الملخص EN

In this study, 19 sites representing different habitats in Hail region were regularly visited for two years, in each site 2–5 stands were selected for investigating floristic composition and vegetation types in the area.

A total of 124 species representing 34 families were recorded.

The family Asteraceae is represented by the highest number of species (21 species) followed by the Poaceae (17 species) and the Brassicaceae (10 species) whereas, 15 families including Acanthaceae, Convolvulaceae, Moraceae, Nyctaginaceae and Primulaceae, are represented by a single species each.

Chronological analysis of the vegetation in the area revealed the domination of Saharo-Sindian elements in the wild vegetations and of weedy species in the cultivated plots.

Therophytes and chamaephytes are the dominating life forms of the vegetation spectra; therophytes represent 49.20 % and chamaephytes represent 29.00% of the total species in the study area.

Application of TWINISPAN and DECORANA classification and ordination techniques to the data produced seven vegetation groups.

Ruderal habitats comprised two small groups A and F dominated by Phragmites australis and Imperata cylindrical (A), Euphorbia peplus and Sisymbrium irio (F), respectively.

Two vegetation groups (B and G) have been recognized in the mountains and slopes dominated by Launaea mucronata, Trigonella stellata (B) and Ficus palmate and Fagonia bruguieri (G).

Other two groups (C and E) inhabit the desert and mountainous wadies ; these are represented by Gymnocarpos studies have dealt with vegetation analysis and species diversity Saudi Arabia.

Hail region, covers the northern part of the central Najd plateau (Fig.

1), it comprises diverse ecosystems that provide interesting aspects for vegetation and species diversity investigations.

The study by Al-Turki and Al-Olayan (2003) represent a comprehensive contribution to the Flora of the region, whereas the recent study by Sharawy and Alshammari (2008) represents a contribution to the poisonous plants in the Aja Mountains, North of Hail.

However, to our knowledge no studies have dealt with the vegetation analysis in relation to the florestic composition and habitat variation in the region.

The aim of the present work is to study the vegetation in the Hail province in terms of species composition, life form, diversity and vegetation types (groups) in relation to habitat change in the study area.

Multivariate techniques and species diversity indices have been used to differentiate vegetation groups and to assess the relation between the vegetation types in the study area.