Invasiveness of Argemone ochroleuca Sweet in various habitats in Taif, Saudi Arabia

This study was designed to elucidate the role of Argemone ochroleuca Sweet-an exotic worldwide weed-in native desert communities of various habitats (sand plains, dams and wadies) in Taif. The latter is characterized by its high diversity in local climatic and topographic conditions. The inter-relationship between the species invasibility (INV) and its biological features (such as plant size; PS, seed production; SP and seed bank; SB) and between some of community factors (such as species richness; SR and productivity) was studied. Results evinced high seed productivity of Argemone (85, 850 seeds). Species seed bank attained an average value of 7, 736. m -2 . The seed productivity plain habitat was characterized by possessing the highest values of: invasibility, diversity, Argemone size, seed production, seed bank and community productivity compared with the other two habitats. Correlation between invasibility (INV), species richness (SR), plant size (PS), seed productivity (SP) and seed bank (SB) and each other indicated that INV positively correlated with both plant size and seed production. Plant size positively correlated with invasibility and seed productivity. The later positively correlated with invasibility and plant size .On the other hand, there was a negative correlation between INV and SR and SB. A negative correlation was also obtained between SR and all other variables and also between SP and SR and SB. Plant size negatively correlated with species richness and seed bank.