Abstract: Plant invasion seriously threatens the structure and function of ecosystems, and soil nutrient availability (soil nutrient amount and spatial heterogeneity) plays a key role in the successful invasion of introduced species. To explore the effect of soil nutrients on the growth of invasive and native species, a greenhouse experiment was conducted with the invasive species (Wedelia trilobata) and its native congener (W. chinensis) under monoculture and mixture in homogeneous soil environments of three nutrient levels and one heterogeneous environment. Growth measures (e.g., total biomass, root mass, stem mass, leaf mass, number of nodes, and root to shoot mass ratio were measured and the effect of soil nutrients was analyzed. Increased soil nutrient levels significantly promoted the growth of the two species. Soil nutrient heterogeneity improved the root mass and root to shoot mass ratio of W. trilobata, as well as the total biomass, root mass, and stem mass of W. chinensis. Soil nutrient level or nutrient heterogeneity had no significant impact on competition response of W. trilobata. We concluded that compared to its congener, W. trilobata had a higher probability to invade successfully in the higher homogeneous soil nutrient environment, and also in highnutrient patches of the heterogeneous soil nutrient environment.

Key words: method of nitrogen application, utilization, fruit quality, loss, ¹⁵N-urea, absorption, dwarfed apple