[Effects of simulated precipitation changes on plant community characteristics of wetland in the Yellow River Delta, China].

• DOI: 10.13287/j.1001-9332.202205.012
• Publication Date: 2022-05-01
• Authors: Ya-Lin Hou; Guangxuan Han; Lianqi Zhu; Xinge Li; Yingfeng Zhou; Jingwei Xu
• Keywords: Dominance (genetics); Diversity index

Under the changing climate scenario, changes in precipitation regimes are expected to alter soil water and salinity conditions, with consequences on characteristics of plant community estuarine wetland. Here, we used a six-year (2015-2020) manipulation experiment examine how responded Yellow River Delta. The results showed that electrical conductivity significantly decreased, while moisture increased increasing precipitation. Precipitation altered composition. Increased reduced absolute dominance Suaeda glauca salsa, but Triarrhena sacchariflora Imperata cylindrica. Shannon index Margalef richness Compared control, both decreased abundance, frequency coverage. treatment 60% by 54.9%, precipitation, 40% abundance 38.9%, 33.8%, 35.8% 45.7%, respectively. aboveground biomass under being lower than reducing treatment, probably due negative effects flooding stress. In addition, had positive relationship biomass. Aboveground biomass, diversity index, Simpson were negatively related conductivity, was positively moisture. Our revealed regulate growth characteristics, species composition, altering conditions coastal wetland.气候变化背景下,降雨变化能够深刻影响河口湿地土壤水盐条件,而土壤水盐条件是影响植物群落特征的关键环境因子。本研究以黄河三角洲湿地植物群落为对象,依托野外降雨控制试验平台(减雨60%、减雨40%、自然对照、增雨40%、增雨60%),探讨了经过6年降雨处理后湿地植物群落特征对降雨量变化的响应及机制。结果表明: 随降雨量增加,土壤电导率显著降低,土壤湿度显著增大。降雨量变化影响了植物群落物种组成,增雨处理降低了碱蓬和盐地碱蓬的优势地位,提高了荻和白茅的优势地位。随降雨量增加,植物群落Shannon指数和Margalef丰富度指数显著提高。与对照相比,增减雨处理均降低了群落频度、多度和盖度,增雨60%处理群落频度显著降低54.9%,减雨60%、减雨40%、增雨40%、增雨60%处理群落多度分别显著降低38.9%、33.8%、35.8%和45.7%。随降雨量增加,植物群落地上生物量显著增加,但可能受淹水胁迫的影响,增雨60%处理地上生物量显著低于增雨40%。Margalef丰富度指数与地上生物量呈显著正相关;地上生物量、Shannon指数、Margalef丰富度指数、Simpson多样性指数均与土壤电导率呈显著负相关;地上生物量与土壤湿度呈显著正相关。降雨量变化通过改变黄河三角洲湿地土壤水盐条件显著影响了植物群落生长特征、物种组成和多样性。.