The impact of water level changes on the growth and physiology of Arundo donax var. versicolor

Abstract

In order to investigate the effects of water level changes on the growth and physiology of Arundo donax var. versicolor and to understand its adaptive mechanisms to water level fluctuations, this study was conducted. A. donax var. versicolor was selected as the experimental species, and a dual-pot method was employed to simulate both rising and falling water level conditions. The study analyzed morphological characteristics (plant height, stem diameter, leaf traits, root traits), biomass, and photosynthetic features (chlorophyll a, chlorophyll b, chlorophyll a + b, carotenoids) of A. donax var. versicolor under these two water level conditions. The results revealed that (1) under the condition of rising water level, the morphological characteristics and chlorophyll content showed an overall trend of increasing initially and then decreasing with the increase of the rate. The growth rate of 0.2–0.4 cm/d groups were better, while exceeding its tolerance range led to a decrease in photosynthetic pigment content and even cell inactivation. (2) falling water level were more complex, with plant height, stem diameter, leaf length, leaf width, and leaf area being higher in the 0.8–1 cm/d groups, but values for leaf number and root characteristics were lower. This suggests that moderate stress can promote the growth of A. donax var. versicolor, but in the later stages, it can lead to leaf yellowing, root shrinkage, and even death.