Population viability analysis models for Lantana camara L. (Verbenaceae):a weed of national significance

摘要

Lantana camara is a recognised weed of national and world-wide significance due to its extensive distribution and its impact on primary industries, conservation and biodiversity. However, no attempt to date has been made to carry oijt any populationviability analysis (PVA) studies on the weed, despite the widely held view that PVA when done in concert with sensitivity analysis and numerical simulations could help greatly in fine-tuning management strategies for control of invasive organisms. Consequently, long-term demographic data on permanently marked individual plants (-2000 plants) across four sites in SE Queensland varying in landscape and land-use types are being collected to aid in simulation and a better understanding of the population growth of the weed. We are into the second year of this survey, and some preliminary results on seed-bank, plant fecundity, surval and growth as well as population dynamics of the weed under various management simulations will be presented. At most sites and as expected of a noxious weed, population growth rate (X) was well above unity (across sites, mean X = 3.449).plasticity and numerical analyses suggest that at its expansion phase any control effort will have to jointly reduce fecundity, seed germination and seedling to juvenile/adult plant transitions by at least 95% to halt the invasion.