Adaptation Mechanism of Three Herbs in the Water-level-fluctuation-zone of Reservoir to Complete Submergence

Abstract:

In order to understand the adaptive mechanism of three plant species, including Phalaris arundinacea, Hemarthria altissima and Cynodon dactylon, in the water-level-fluctuation-zone (WLFZ), dynamic changes in ecological and physiological indicators, such as branch, leaf, biomass, soluble sugar, starch and root vigor, were studied. The results showed that P. arundinacea, H. altissima and C. dactylon did not generate new branch, and reduced total leaf number, total leaves length and biomass for adapt to submergence environment. P. arundinacea and C. dactylon adapted to complete submergence by slow growth, while H. altissima accelerated growth at first and then inhibited growth to preserve vitality. P. arundinacea, H. altissima and C. dactylon consumed little carbohydrate, reduced root vigor to adapt complete submergence. The tolerance of prolonged submergence of the three herbs is as the following: C. dactylon > P. arundinacea > H. altissima.