Pollen Morphology, Seed Biology, and Dispersal Ecology of Prosopis juliflora as an Invasive Weed in Dryland Farming

Abstract

Pollen morphology, seed biology, and dispersal ecology of Prosopis juliflora were investigated to understand its invasive success in dryland farming systems. Field and laboratory analyses were conducted to examine pollen traits, seed germination behavior, and dispersal mechanisms under semi-arid environmental conditions. Pollen grains exhibited characteristics associated with efficient wind-mediated transfer, including small size and high viability, supporting effective cross-pollination across fragmented landscapes. Seed biology assessments revealed high seed production per plant, with a substantial proportion of seeds exhibiting dormancy mechanisms that facilitate persistence in soil seed banks under harsh moisture-limited conditions. Germination studies indicated that scarification and environmental cues such as temperature fluctuations significantly enhanced germination rates, highlighting adaptive strategies for episodic recruitment following rainfall events. Dispersal ecology analysis showed that seeds are primarily dispersed through endozoochory, particularly via livestock and wild herbivores, as well as secondary spread through water runoff and human-mediated transport. The combined reproductive and dispersal traits contribute to rapid colonization and dense stand formation in dryland agricultural ecosystems. The species demonstrated strong ecological plasticity, enabling establishment in disturbed habitats and competitive displacement of native vegetation and crops. The study underscores the integrated role of reproductive biology and dispersal strategies in the invasiveness of P. juliflora. These findings provide a basis for designing targeted management strategies focusing on seed bank depletion, dispersal barrier creation, and integrated weed control in dryland farming systems.