Exploring the relative contribution of flood regimes and climatic factors to Carex phenology in a Yangtze River-connected floodplain wetland

• Published in: The Science of the total environment Vol. 847; p. 157568
• Main Authors: Huang, Ying, Chen, Xin-sheng, Zou, Ye-ai, Zhang, Ping-yang, Li, Feng, Hou, Zhi-yong, Li, Xu, Zeng, Jing, Deng, Zheng-miao, Zhong, Jia-rong, Xie, Yong-hong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2022
• Subjects: Climate change; Freshwater wetlands; Hydrological changes; Phenological response; Vegetation phenology; Freshwater wetlands; Climate change; Vegetation phenology; Phenological response; Hydrological changes
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.157568

Hydrological regimes can combine with climatic factors to affect plant phenology; however, few studies have attempted to quantify their complex influences on plant phenology in floodplain wetlands. We obtained phenological information on Carex vegetation through MODIS normalized difference vegetation index (NDVI) data during 2001–2020, and monthly field investigation during 2011–2020. We then explored how these data were correlated with climatic factors and flood regimes in a Yangtze River-connected floodplain wetland (Dongting Lake, China). Our results showed that warmer temperature tended to advance the start of the pre-flooding growing season (SOS1), with a relative contribution of 76.1 %. Flood rising time strongly contributed to controlling the end of the pre-flooding growing season. Flood recession time and inundation duration were dominant factors determining the start of the post-flooding growing season (SOS2). Earlier flood recession time and shortened inundation duration tended to advance the SOS2. Shortened inundation duration, earlier flood recession time, and lower solar radiation tended to advance the end of the post-flooding growing season. The phenology of Carex distributed at high-elevation areas was more affected by hydrology than that of Carex distributed at low-elevation areas. Thus, climatic factors strongly affect the phenology of Carex during the pre-flooding growing season, whereas flood regimes play a dominant role in determining the phenology in the post-flooding growing season. The different responses of Carex phenology to climatic and flooding factors may provide insights for the conservation and management of floodplain wetlands in Yangtze River because Carex are primary food source and habitat for herbivorous waterfowls. [Display omitted] •Flood may combine with climate to affect Carex phenology in wetlands.•Climate and hydrology are dominant in pre- and post-flooding season respectively.•Carex phenology in high-elevation areas was more severely affected by hydrology.