水动力及种源高程对盐沼植物定植初期种子扩散影响  

Effects of hydrodynamics and provenance elevations on the seed dispersal in the early stage of colonization of salt marsh plant

作　　者：陆修芝 王宪业 袁琳[1] 彭忠 LU Xiuzhi;WANG Xianye;YUAN Lin;PENG Zhong(State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200241

出　　处：《海洋通报》2023年第1期19-29,共11页Marine Science Bulletin

基　　金：上海市科委国际科技合作项目(19230711900);国家自然科学联合基金(U2040216);上海市科委社会发展科技攻关项目(21DZ1201803;21DZ1201700);上海崇明东滩鸟类国家级自然保护区资源监测专项(CMDT-JC202101)。

摘　　要：不同的水动力条件及种源高程会影响盐沼植物定植初期的种子扩散活动,导致盐沼不同的扩张格局,进而影响其对潮滩防护工程的补充保护作用。以崇明东滩优势先锋种——海三棱藨草(Scirpus mariqueter)作为研究对象,基于无网格数值模拟方法,研究不同波高(0.01~0.11 m)、水深(0.3~2.5 m)、种源所处高程(1.3~3.1 m)等条件对定植初期种子扩散活动的影响。结果表明:种子在海陆方向和沿岸方向上的扩散距离与波高呈高度正相关,且当波致切应力达到一定值时,种子在两方向上均存在扩散距离突变现象;种子在海陆方向和沿岸方向上的扩散距离与水深呈显著负相关,且随水深增大种源扩散前端位置离岸距离减小;此外,种子在海陆方向和沿岸方向上扩散距离与种子所处高程均呈负相关。研究结果解释了盐沼植物种子扩散活动的机制,从而为以种子为生态修复材料,以“机会窗口”为概念的生态修复工程提供科学解释。Different hydrodynamic conditions and provenance elevations may affect the seed dispersal activities in the early stage of salt marsh plant colonization,leading to different expansion patterns of salt marshes,which plays a supplementary role in the protection of tidal flats.Taking Scirpus mariqueter,the dominant pioneer species of Chongming Dongtan,as the research object,based on the meshfree numerical simulation method,the effects of different wave heights(0.01~0.11 m),water depths(0.3~2.5 m),and the elevations of the provenance(1.3~3.1 m)on seed dispersal activities were studied.The results show that the wave height is highly positively correlated with the seed dispersal distances in the sea-land direction and alongshore direction,and when the wave-induced shear stress reaches a threshold value,the seed dispersal distances have abrupt changes in both directions.There is a significant negative correlation between the water depth and the seed dispersal distance in the sea-land direction and alongshore direction,and as the water depth increases,the front position of the seed is located more landward.In addition,the elevation of the provenance is negatively correlated with the seed dispersal distance in both the alongshore and sea-land direction.This study reveals the mechanism of the seed dispersal activity of saltmarsh plant,thereby providing a scientific explanation for the ecological restoration project using seeds as ecological restoration materials and the concept of"Window of Opportunity".

关 键 词：海三棱藨草 种子扩散 光滑粒子流体动力学(SPH) 数值模拟 波致切应力 

分 类 号：P731.2[天文地球—海洋科学] TV148[水利工程—水力学及河流动力学]