Response of Carex moorcroftii leaf anatomical structure to habitat aridification

Leaves are the largest and more sensitive vegetative organs exposed to external environmental conditions. In order to investigate the effects of habitat aridification on the leaf anatomical structure of wetland plants, Carex moorcroftii leaf plots were set up along the gradient of habitat aridification, and the response of leaf anatomical structure to habitat aridification was analyzed in this study. The results were as follows:(1)The epidermal cells, bulliform cells and air cavity area on the abaxial surface of leaf tip and leaf base, leaf thickness and mechanical tissue thickness at leaf base were significantly positively correlated with soil volumetric moisture content(R2=0.06-0.34, P<0.01); the paraxial cuticle thickness, cell area, number of vascular bundles in parts of leaf tip, leaf middle and leaf base, and diameter of vascular bundle in leaf middle were significantly negatively correlated with soil volumetric moisture content(R2=0.08-0.53, P<0.01).(2)The anatomical structure of C. moorcroftii leaf had great plasticity(0.53-0.94)and variability(18%-63%), and bulliform cells, air cavities, and paraxial epidermal cells had the greatest plasticity and variability, and the plasticity index and the coefficient of variation of leaf base anatomical structure were significantly higher than that of leaf tip and leaf middle(P<0.05). When the habitat was aridified, C. moorcroftii leaf adapt to the arid habitat by thickening the cuticle on the paraxial surface, increasing the epidermal cell area, decreasing the air cavity area, and differentiating middle cells, and mainly adopted protective and frugal strategies to adapt to the arid habitat. The results of this study are helpful to reveal the response strategies of C. moorcroftii leaf anatomical structure to arid habitat, and provide theoretical reference for protection and vegetation restoration of alpine meadow.