Demographic Analysis of Cornulaca Monacantha Delile Population in Asir Region, Saudi Arabia

The present paper aims to study the demography and growth strategy of Cornulaca monacantha Del i le population under natural and experimental conditions in Asir region, Saudi Arabia (in terms of size structure, natal i ty, mortal i ty, and demographic flux) and to assess i ts standing crop and the correlat ion between its population characters and the prevail ing environmental variables. Thirty permanent stands were establ ished to represent the microvariations in five habitats, where C. monacantha inhabits. In each stand, the height from the ground and the average diameter of the canopy for each C. monacantha individual were est imated monthly and i ts volume was calculated as a cyl inder. The results showed significant variation in i ts growth variables in relat ion to habitat types. The growth fol lows a seasonal pattern, where the highest values for most growth variables were obtained during Marsh and Apri l , while the lowest during October and November. The plant has two peaks of mortal i ty: the f i rst in January mainly due to heavy death of the seedl ings and juveni les, while the second in June associated with the end of i ts l i fe cycle. I ts size structure was characterized by the preponderance of the young individuals comparing with the old ones. Regarding the density effect, the individuals were bigger and had more leaves under low than under high density. Density affected also the pattern of leaf distribution, length and number of branches and internodes.