Environmental impacts of riparian diversity-stability relationships

The study was carried out in the riparian zones of the Three Gorges Dam Reservoir (TGDR) (28.17−32.05°N, 105.73−111.12°E), which extends 660 kilometers along the Yangtze River Basin from Yichang in Hubei Province to Jiangjin in Chongqing Municipality. TGDR has a humid subtropical monsoon climate, with an average temperature of 18.22 ± 0.56°C and average precipitation of 1110 ± 75.23 mm. Herbaceous species such as <i>Xanthium strumarium</i>,<i> Cynodon dactylon</i>, and <i>Hemarthria compressa</i> predominate and contribute significantly to the primary biomass in this region.Thirty-five sampling sites were selected in the riparian zone of the TGDR, spanning the entire mainstem of the Yangtze and its tributaries within the TGDR. These sites were selected to avoid disturbance from anthropogenic activities and were dominated by herbaceous plants in the natural landscape.We subdivided each site into four intervals along the elevation and then set up three 4 m² quadrats (2 m × 2 m) at 50 m intervals within each interval . Thus, 12 quadrats were included in each site, with some exceptions due to the smaller riparian widths or steeper topography in these sites limiting field surveys. A total of 399 quadrats were obtained for this study.