铁路沿线沙生植物种子风传扩散的数值风洞模拟

Numerical Wind Tunnel Simulation of Psammophyte Seed Wind Dispersal Along Railway Lines

为了研究铁路沿线沙生植物种子风传扩散机制所体现出的生态适应策略,本研究以辽西北铁路沿线沙区段5种蒿属植物为研究对象,借助流体动力学方程和计算机图形学技术,采用数值风洞方法,模拟预测了在不同风速及释放高度条件下各物种种子扩散时间和扩散距离的变化趋势。软件模拟结果表明:(1)在释放高度和风速条件相同的情况下,5种蒿属植物种子的飞行时间和飞行距离与种子重量表现出相反的趋势,即随着种子重量的增大,其水平飞行时间和飞行距离减短。(2)在释放高度相同风速条件不同的情况下,5种蒿属植物种子的飞行时间和飞行距离与风速表现出相同的趋势,即种子的飞行时间和飞行距离随着风速的增大而增加。(3)在风速条件相同释放高度不同的情况下,5种蒿属植物种子的飞行时间和飞行距离与释放高度表现出相同的趋势,即种子的飞行时间和飞行距离随着释放高度的增加而增加。种子重量、风速及释放高度是影响种子扩散时间和扩散距离的敏感因素,在铁路沿线沙化地区筛选适宜的植物防沙措施进行生态修复的同时应结合考虑这些影响因素。

To study the ecological adaptation strategy of the seed wind dispersal mechanism of psammophytealong railway lines, 5 Artemisia species along railway lines in sand dune areas in northwestern LiaoningProvince were studied. With the aid of the fluid dynamics equation and computer graphics technology, thenumerical wind tunnel was used to simulate and forecast the variation trend of seed dispersal time anddispersal distance at different wind speed and seed releasing heights. The results of software simulation showedthat：（1） at the same seed releasing heights and the same wind speed, the flight time and flight distance of 5 Artemisia species showed the opposite trend with seed weight, the horizontal flight time and flight distancewere shortened while the seed weight increased;（2） at the same seed releasing heights and the different windspeed, the flight time and flight distance of 5 Artemisia species showed the same trend with wind speed, theflight time and flight distance increased while the wind speed increased;（3） at the same wind speed and thedifferent seed releasing heights, the flight time and flight distance of 5 Artemisia species showed the sametrend with seed releasing heights, the flight time and flight distance increased while the seed releasing heightsincreased. Seed weight, wind speed and seed releasing heights are sensitive factors that influence seeddispersal time and dispersal distance, and should be taken into consideration in the selection of suitable plant sand-control in the sandy area along railway lines for ecological restoration.