Pattern of Survival and Mortality of Mangrove Populations Grown at Al-Jubail Area (Saudi Arabia) of the Arabian Gulf

Abstract

The life table and fecundity schedule were produced for [Avicennia marina (Forsk.) Vierh] populations of four habitat types at Al-Jubail area, KSA. These types are sand mounds, salt flats, shoreline and intertidal sites. Survivorship (lx) was least in sand mounds and similar in all other sites. Age-specificmortality rates (qx) where parallel in the flower bud, flower, fruiting and seedling stages in all sites, while demonstrated site-specific variations in adult stages with highest values in the shoreline and salt flat sites. The killing power (kx) values were parallel in all sites except for the sand mounds. The expectations of future life (ex) were variable at different age classes and sites with highest values attained in the intertidal and shoreline sites. Plants in the sand mounds and salt flats showed lower expectations for future life than in the other habitats. The reproductive values were close to zero in all age classes of the salt flats site. The net reproduction rate (R0) ranged from 0.023 to 0.4 with negative or close to zero intrinsic rate of increase per capita (r). The generation time (T) ranged from 25.6 years in the sand flats to 53.75 years in the sand mounds. This study supported that the conservation of Avicennia marina may allow for continued dynamic adaptation to different habitat types in the Arabian Gulf coast. Key words: Mangrove habitats, growth stages, life rate, killing rate