Impact of Nutrients on Reproduction from Fragments of Invasive Alien Species Alternanthera philoxeroides

Abstract

Invasive alien species Alternanthera philoxeroides was found on Lake Biwa shore for almost two decades and has been causing huge loss for this region. This study aims at investigating three impact factors on reproduction of A. philoxeroides, namely nutrients, stem length, and stem diameter. Utilizing a ternary configuration dispersion method on 120 fragment samples collected from Lake Biwa shore after 10-days cultivation, the result indicates that nutrient salts significantly enhance growth (p < 0.01, Welch’s t-test), highlighting the species' preference for eutrophic environments. Smaller stem fragments exhibit reduced growth, emphasizing the importance of thorough removal to minimize its persistence. Comparative analysis with Ludwigia grandiflora underscores that the latter exhibited bigger leaves under same experiment condition, and stem diameter significantly influence on its growth (37.7% contribution rate). These findings not only offer valuable references for elimination activities, but also stress the need for appropriate eradication strategies to preserve Lake Biwa’s aquatic ecosystem, contributing valuable insights to invasive species management in ecologically sensitive areas.