BIOMASS, PRODUCTIVITY, AND DOMINANCE OF ALIEN PLANTS: A MULTIHABITAT STUDY IN A NATIONAL PARK

Abstract

The invasion of natural and anthropogenic habitats by alien plants is a global problem. To understand the factors that regulate the success of alien plant species we sampled alien plant biomass and species composition in 66 sites representing a wide variety of habitat types within Bruce Peninsula National Park, Ontario, Canada. We quantified the response of existing alien biomass to a suite of habitat variables including habitat productivity, standing biomass, species richness, soil nutrients and disturbance factors. Standing biomass in the sites varied from 0 to nearly 60 000 g/m2 and annual productivity ranged from 0 to nearly 800 g·m−2·yr−1. The response of both absolute and relative alien biomass (dominance) to the independent variables was assessed using univariate plots and multivariate canonical correspondence analysis. The results show that total standing alien biomass and site disturbance history can predict alien dominance, but other factors including primary productivity, nutrient levels, and s...