The effects of physical prevention and control on the growth of Spartina alterniflora and macrobenthos in coastal wetlands: a case study from Dongtai Tiaozini Wetland, Yancheng City, Jiangsu Province

Spartina alterniflora, a typical invasive plant in wetlands, poses serious threats to biodiversity and ecological security in coastal wetlands. Effective control of S. alterniflora has therefore become a crucial issue in coastal wetland management. A field experiment was conducted in the Tiaozini Wetland, Dongtai, Yancheng City, Jiangsu Province, using a two-factor interactive design to investigate the effects of different physical control measures: namely, control (no treatment), mowing, mowing plus coverage with white plastic film, and mowing plus coverage with black plastic film+across different treatment timings (end of the current growing season, beginning of the next growing season, and peak of the next growing season) on the growth and reproduction of Spartina alterniflora, the recovery of the native plant Suaeda salsa, macrozoobenthos communities, and soil physicochemical properties. The results indicated that physical control measures had significant effects on all growth indicators of Spartina alterniflora except belowground biomass. Among these measures, the combination of mowing and black film coverage demonstrated increasingly pronounced control efficacy over time. Moreover, the density of the native plant Suaeda salsa significantly increased under mowing plus film coverage treatments. No significant changes were observed in the density and biomass of macrozoobenthos under the mowing plus coverage treatments; however, both macrozoobenthic density and biomass were significantly higher at the end of the current growing season compared to other periods. Soil moisture content significantly increased after the mowing plus coverage treatments and recovered more rapidly compared to mowing alone. In conclusion, mowing combined with black film coverage proved highly effective in controlling Spartina alterniflora, while exhibiting minimal impact on macrozoobenthic density and other related indicators. Furthermore, this treatment facilitated the recovery of the native plant Suaeda salsa.