Vegetation survey of Qawra Point peninsula

Abstract

The study performed was spread over a period of one year. In April 1993, grid sampling was used to investigate the vegetational structure in the region of open vegetation, seven line intercepts were laid down the slope to study the variation in vegetation from the uppermost part of the slope to its base. Fourteen intercept lines were laid down the slope and the heights of shrubs of Inula crithmoides and Arthrocnemum glaucum intercepted were measured. Grid sampling was performed during December 1993 since eight other species were encountered. Weekly visits on site were made in order to study the flowering dynamics of the plant community. The raw data obtained are used to calculate relative density, relative coverage, relative frequency, importance value and sociability index. Species richness and dominance-diversity curves were also produced. Type of dispersion was determined using Morisita's index and species diversity using Simpson's diversity index. Variation in height of I.crithmoides and A.glaucum down the slope was analyzed using regression statistics. Distribution of vegetation was analyzed using relative coverage data while distribution of Raunkiaerian life-forms which was useful for microclimatic analysis, was analyzed using relative density data. The study shows that vegetation distribution is highly dependent on topography, microclimate and exposure to wind and salt spray. The peninsula is divided into a chamaephyte, chamaephyte/hemicrptophyte co-dominating zone and a therophyte zone, in the most sheltered area. Regression statistics showed that heights of shrubs increase down the slope while phenology showed that for some species period of flowering was different from that documented for the same species elsewhere.