Compensatory growth and water physiological characteristics of Atriplex canescens under stubble treatment

Abstract

[Objective] Atriplex canescens is a high-quality xerophytic shrub widely introduced in desertification control areas, and stubble is a main management measure for desertification control. Revealing the adaptability and compensatory growth mechanism in the recovery process after stubble can provide theoretical support for developing A . canescens into a high-quality feed in desert areas. [Methods] In this study, 5-year-old A . canescens plants were used as object. Through stubble treatment, plant height, crown width, photosynthetic reaction, leaf water potential, leaf hydraulic conductivity, and water use efficiency were measured during the recovery process of A . canescens, and the relationship between functional traits was discussed. [Results] (1) The plant height, crown width, and aboveground biomass of A . canescens after stubble were recovered to the pre-stubble state after a growing season. (2) The leaf water potential, leaf hydraulic conductivity, water use efficiency, and photosynthetic parameters of the stubble plants were higher than those of the control plants. (3) Linear fitting analysis showed that the midday leaf water potential and stomatal conductance of the stubble plants were significantly positively correlated with the growth rate. [Conclusion] A . canescens had good compensatory growth ability after stubble. In the early stage of recovery growth, the flat stubble plants showed higher compensatory growth ability and typical acquisition strategy, and then turned to conservative strategy with the decrease of hydraulic condition in the later stage. Stubble plants allocated more biomass and resource to the growth of aboveground parts such as branches and leaves, and the later resource allocation turned to the growth of underground parts.

Keywords

• atriplex canescens
• stubbling
• compensatory growth
• photosynthetic response
• ecological adaption