Functional traits underlying performance variations in the overwintering of the cosmopolitan invasive plant water hyacinth (Eichhornia crassipes) under climate warming and water drawdown

Abstract

Aim: Reports of the Intergovernmental Panel on Climate Change (IPCC) indicate that temperature rise is still the general trend of the global climate in the 21st century. Invasive species may benefit from the increase in temperature, as climate can be viewed as a resource, and the increase in the available resources favors the invasibility of invasive species. This study aimed to assess the the overwinter survival and growth of the cosmopolitan invasive plant, water hyacinth (Eichhornia crassipes) on its northern boundary.Location: Eastern ChinaMethods: Using E. crassipes as a model plant, a cross-year mesocosm experiment was conducted to determine 20 plant functional traits, including growth, morphological, root topological, photosynthetic and stoichiometric traits, under climate warming (ambient, temperature rise of 1.5°C and 3.0°C) and water drawdown (water depth of 1 cm, 10 cm and 20 cm) treatments.Results: The overwinter survival and growth of E. crassipes were facilitated by climate warming and proper water drawdown, and climate warming played a leading role. A temperatrure rise of 3.0°C and a water depth of 10 cm are the most suitable for the overwinter of the plant.Main conclusions: Controlling the temperature to within 1.5°C, an ambitious goal for China, still facilitated the overwintering of E. crassipes. With climate warming, the plant can overwinter successfully, which possibly assists it in producing and spreading new ramets in the vernal flood season. The new rooting behavior induced by low temperature may be viewed as a unique survival adaptation strategy and a change in a niche that helps these plants invade empty niches left by dead free-floating plants on the water surface caused by freezing in winter. With the continued global warming, the distribution of the plant may expand northerner and eradication of the plant during the winter water drawdown period may be more effective.