Effects of planting density on the growth and photosynthesis of Alternanthera philoxeroides at different nutrient conditions.
In order to reveal the effects of planting density on the performance of invasive plant under different nutrient conditions, a greenhouse experiment was conducted in which Alternanthera philoxeroides was planted at three population densities (low, medium and high) under various nutrient levels (low, medium and high). The results showed that both population density and nutrient level had significant effects on the growth of the plant. The biomass of individual plant and all plants in one pot under medium nutrient level were the highest, while the photosynthetic rate and total chlorophyll content were the highest at the high nutrient level. The photosynthetic rate was the highest at medium population density under every nutrient level. The photosynthesis and biomass of single plant decreased with the increase of population density, while the total biomass in the whole pot increased with the increase of density. These characteristics might contribute to the invasion of A. philoxeroides to form monodominant community. This study contributes to the understanding of invasion mechanism of A. philoxeroides and other similar invasive plants.