Effects of nutrient supply on leaf stoichiometry and relative growth rate of three stoloniferous alien plants

Abstract

Different nutrient supply brings about changes in leaf stoichiometry, which may affect growth rate and primary production of plants. Invasion of alien plants is a severe threat to biodiversity and ecosystem worldwide. A pot experiment was conducted by using three stoloniferous alien plants Wedelia trilobata, Alternanther philoxeroides and Hydrocotyle vulgaris to investigate effects of nutrient supply on their leaf stoichiometry and relative growth rate. Different nitrogen or phosphorus supply was applied in the experiment (N1:1 mmol L-1, N2:4 mmol L-1, and N3:8 mmol L-1, P1:0.15 mmol L-1, P2:0.6 mmol L-1 and P3:1.2 mmol L-1). Nitrogen and phosphorus concentrations in leaves of the three alien plants significantly increased with increase of nitrogen supply. With increase of phosphorus supply, nitrogen or phosphorus concentration of leaf was complex among the three alien plants. N:P ratio in leaf of the three alien plants subjected to different levels of nutrient supply was various. A positive correlation between relative growth rate and N:P ratio of the leaf is observed in W. trilobata and A. philoxeroides suffering from N-limitation. A similar pattern was not observed in Hydrocotyle vulgaris. We tentatively concluded that correlations between relative growth rate and N: P ratio of the leaf could be affected by species as well as nutrient supply. It is suggested that human activities, invasive history, local abundance of species et al maybe play an important role in the invasion of alien plants as well as relative growth rate.

Annual Weeds Suppression and Oat Forage Yield Responses to Crop Density Management in an Oat-Cultivated Grassland: A Case Study in Eastern China

“…In plant tissue, N and P exhibit a close stoichiometric scaling relationship when there is a functional coupling between them, representing the synchronized plant species-specific demand and limitation for N and P nutrient [14]. Plant N and P stoichiometry tend to be flexible to changes in neighbor identity and/or soil resource conditions, suggesting that plant stoichiometry could have a complexity ecological relation in the plant-soil system [15]. Previous studies have found that high N, P-requirement weed species are greatly affected by intense crop competition in nutrient element acquisition compared to low N, P−requirement weeds [16][17][18].…”