Seasonal variability of groundwater level effects on the growth of Carex cinerascens in lake wetlands

Groundwater level is crucial for wetland plant growth and reproduction, but the extent of its effect on plant growth can vary along with changed precipitation and temperature at different seasons. In this context, we investigated the effect of two groundwater levels (10 cm vs. 20 cm depth) on growth and reproductive parameters of Carex cinerascens, a dominant plant species in the Poyang Lake wetland, during three seasons (spring, summer and autumn) and during two consecutive years (2015 and 2016). Carex cinerascens showed low stem number, height, individual and population biomass in summer compared to spring and autumn. Lower groundwater depth was overall more suitable for plant growth resulting in higher stem height and biomass. However, the interactive effect between groundwater level and season clearly demonstrated that the effect of groundwater level on plant growth occurred mainly in autumn. After the withering of the plant population in summer, we observed that C. cinerascens grow...