[Comparison of ecological characteristics of Carex tussock under natural and artificial reco-very.]

We compared the ecological characteristics of tussock individuals and populations undergoing natural and artificial restoration in Carex tussock wetlands in the Sun Island in Harbin and identified the relationships between the growth of Carex tussock and environmental factors. Results showed that there were obvious seasonal dynamics in morphological characteristics of C. appendiculata. Tussocks grew rapidly from May to June, peaked in June, and then decreased steadily from July to August. There were significant differences in ecological characteristics of Carex tussocks between natural and artificial restorations. The morphological characteristics of individual tussock, including leaf area, leaf width, fresh weight per ramet, dry weight per ramet, and the hummock shape indicators (hummock height, diameter, volume and surface area) in natural restored area were significantly higher than those in artificial transplanting area. For the Carex tussock community, tussock density, coverage and biomass in natural restoration area were significantly lower than those in artificial transplanting area. Soil water content, water depth and hummock spacing in natural restoration area were significantly higher than those in artificial restoration area, which facilitated the formation and development of individual tussock. Higher transplanting density was the main factor leading to higher density, coverage, and biomass in artificial restoration area. Our results suggested that the distribution characteristics of tussocks in natural restoration area should be taken into account in future restoration and protection works. Appropriate adjustment of the distance between hummock (54.22-117.89 cm) and population density (1.9-3.1 ind·m^-2), as well as proper water recharge measures in spring in arid areas to regulate soil water content and water depth, would be conducive to promoting the growth and rapid recovery of Carex tussock, which would maintain the long-term health and stability of tussock wetland.