Study on water level ecological amplitude of Typha orientalis seedlings

Abstract

Typha orientalis is an important aquatic plant and is sensitive to the water level. Here, the ecological amplitude of T. orientalis under different water levels was determined by measuring its growth and physiological indices. Results showed that: (1) The growth characteristics of T. orientalis showed quadratic relationships with water level, plant height, withered leaf rate, base diameter, leaf length, leaf width, leaf area, and biomass. Each of these growth characteristics showed an increasing then decreasing trend as water level was increased. (2) Most physiological characteristics of T. orientalis (Chla, Chlb, Car, SOD activity, CAT activity, soluble protein content, and root activity) also showed quadratic relationships (increasing then decreasing) with an increase in water level. Conversely, POD activity and MDA content showed an inverted quadratic relationship, as they decreased then increased as water level increased. (3) We determined an optimum water level for T. orientalis growth of 14.43 cm, a range of limiting water levels for T. orientalis growth of −52 cm to 74.93 cm, with the range of −19.75 to 42.55 cm being the most suitable for growth. Water levels in excess of 74.93 cm and below −52 cm cannot facilitate the normal growth and development of T. orientalis.

Keywords

• typha orientalis
• ecological amplitude
• water level