Growth and physiological responses of Carex schmidtii to water-level fluctuation

Abstract

Water-level fluctuations are common abiotic stresses influencing growth and physiological processes of wetland plants. Nonetheless, little is known about plant eco-physiological responses and growth strategy under multi-hydrological processes. Carex schmidtii was grown under the conditions with interaction of initial water-level depth (DW) and water-level amplitude (AW). Dynamics of plant eco-physiological traits and growth strategy were investigated continuously during the entire growth stages. Results indicated that leaf morphology was significantly affected by DW and lasted time, and leaf width was sensitive to AW. The SLA and LDMC of C. schmidtii varied significantly at different lased time, and their relationships indicated the trade-off in leaves between matter production and nutrient conservation. Increasing DW inhibited matter production of C. schmidtii in early growth stage, but increased nutrient conservation in late growth stage. However, increasing AW contributed to both increase of matter production and nutrient conservation of C. schmidtii. The photosynthetic pigments of C. schmidtii are relatively sensitive to DW, AW and their interaction. Slowing down water-level fluctuations and appropriate water management in the key growth stage will assist with the adaption of Carex schmidtii. The findings provide invaluable supporting information for the management and conservation of C. schmidtii tussock wetlands.