流动沙丘先锋灌木差巴嘎蒿的种子散布格局

Seed Dispersal Patterns of Artemisia halodendron Growing in the Dune-shifting Habitats

通过对科尔沁沙地流动沙丘上先锋植物差巴嘎蒿的种子散布格局及机理的实验研究,主要得出以下结论:差巴嘎蒿母株向不同方向散布的种子,其数量与距离存在明显的差异.母株向西南方向散布的种子数量最多,种子累积数量高达4 590±1 260,比其它各方向多29%至12倍.向北方向散布的种子数量最少,距离最短,种子累积数量为344±44,距离仅在100 cm的范围内.不同方向差巴嘎蒿种子散布的密度均随着散布距离的增加而呈对数关系减小,表现出显著的相关性.不同方向差巴嘎蒿远离母株的种子散布密度与累积面积之间存在显著的相关性,其间关系可用对数曲线来描述.结果显示,差巴嘎蒿向不同方向散布的种子密度均随着累积面积的增加而增加.

In Horqin tibba with shifting dunes, the seed-dispersing patterns and mechanisms of Artemisia halodendron as a pioneering plant were investigated and this revealed that maternal Artemisia halodendron plants dispersed their seeds in remarkably different quantities and distances in different directions. They dispersed the largest proportion of their seeds in southeast ,which amounted to （4 590±1 260） seeds/m^2, and was 29% to twelve times higher than those in the other directions. They dispersed the smallest proportion of their seeds in north ,which amounted to （344±44） seeds/m^2 and only distributed within 100 m. All the densities of the seeds that maternal Artemisia halodendron plants dispersed in the different directions appeared to logarithmically decrease with increased seed-dispersing distances,which showed a significant correlativity. The densities of the seeds that maternal Artemisia halodendron plants dispersed far away had a significant correlativity with the accumulative dispersal areas of the seeds,which could be depicted by a logarithmic curve. These results showed that the densities of the .seeds dispersed in all the different directions increased with the accumulative dispersal areas of the seeds.