© 2011 E. SchweizerbartÕ sche Verlagsbuchhandlung, Stuttgart, Germany www.schweizerbart.deDOI: 10.1127/1869-6155/2011/0129-0033 1869-6155/2011/0129-0033 $ 08.00

Plant Div. Evol. Vol. 129/1, 27–58 E Published online January 2011

A first synthesis of the flora and vegetation of the Tayma oasis and surroundings (Saudi Arabia)

By Harald Kürschner and Reinder Neef

With 8 figures and 9 tables

Abstract

Kürschner, H. & R. Neef: A first synthesis of the flora and vegetation of the Tayma oasis and surround-ings (Saudi Arabia). — Plant Div. Evol. 129: 27–58. 2011. — ISSN 1869-6155.

Based on field studies in February 2009, the flora and vegetation of the Tayma oasis and surroundings is described and analysed for the first time. The phytosociological survey reveals six communities who’s distribution is determined mainly by geomorphological and edaphical factors. Typical for the rock (hammada), gravel deserts (reg) and the Qraya area of old Tayma is a Fagonia bruguieri com-munity, which is replaced on the extended sandy desert plains and sand sheets in the surroundings by two communities, typical for North Arabia: the Rhanterium epapposum community (‘arfaj’ shru-bland; on rocky outcrops overblown with aeolian sands) and the Haloxylon salicornicum community (‘rimth’ shrubland; sandy desert plains). On sand dunes, the Artemisia jordanica community (‘adhir’ shrubland) dominates. The sabkha north of Tayma shows a sparse vegetation of an Aeluropus littora-lis community. In all communities (except the latter one), a luxuriant growth of a ‘vernal aspect’ is favoured after winter rainfalls, consisting of many widespread winter annuals and psammophytic ephemerophytes, derived from a common Saharo-Arabian floral stock. The wadis in the Tayma area are vegetated by very open, xeromorphic woodland consisting mainly of Acacia gerrardii and A. torti-lis. They remain unstudied at present. Most of these wadis, today are destroyed, or heavily devastated by wood cutting, use as fuel reserve and/or sediment digging. A chorotype analysis of the communi-ties documents the strong Saharo-Arabian character of the Tayma vegetation. The final floral historical remarks give a first insight in the apparently younger vegetation history of the area.

Keywords: Arabia, chorotypes, floral history, phytosociology, rock desert, sabkha, sand desert.

Introduction

Up to now north-western, northern, and eastern Arabia are poorly studied with respect to vegetational aspects and methodologically well based studies (e. g., multivariate analysis, phytosociology) still are a rarity for this large area. Most studies available are descriptive and consist of more or less summarizing articles. One could mention Chaudhary (1983), Chaudhary & Al-Jowaid (1999), El-Sheikh & Chaudhary (1987), Frey & Kürschner (1989), Giacomini et al. (1979), Kürschner (1998), Mandaville (1990, 1998), Migahid & El-Sheikh (1982/1983), Miller & Cope (1996), Popov & Zel-ler (1963), Schulz & Whitney (1986), Shaltout & Mady (1993), Vesey-Fitzgerald