Secondary diaspore dispersal by wind, that is, wind‐driven movement along the ground surface (GS), is important for the structure and dynamics of plant populations and communities. However, how wind velocity (WV), GS, and diaspore morphology influence diaspore secondary dispersal by wind are unclear. We used a wind tunnel and video camera to measure the threshold of WV (TWV) and diaspore velocities (DV) of secondary diaspore dispersal. Diaspores of seven Calligonum species with different appendages (wings, bristles, membranous balloon, and wings + thorns) were used to determine the TWV and DV under variable wind speed (4, 6, 8, and 10 m s‐¹) and four GSs (cement, sand, loam, and gravel). GS and diaspore morphological traits explained 37.1 and 18% of diaspore TWV, respectively. Meanwhile, WV, GS, and diaspore morphological traits explained 62.4, 13.6, and 3.2% of DV, respectively. An increasing trend was shown for TWV, and a decreasing trend was shown for DV in the order of cement, sand, loam, and gravel surfaces. Spherical and light diaspores had low TWV and high DV, whereas winged and heavy diaspores had high TWV and low DV. Our results indicated that adaptive features of diaspore appendages might be the result of selection for primary dispersal or secondary dispersal. The mechanism of diaspore secondary dispersal is important for understanding the recovery of degraded sand dunes and providing theoretical support for restoration practices.

中文翻译：

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7种Calligonum物种的二次风传播对环境特征和水铝石形态的响应

风的次生水铝石散布，即沿地表（GS）的风驱动运动，对植物种群和群落的结构和动态很重要。然而，风速 (WV)、GS 和水铝石形态如何影响水硬石风的二次扩散尚不清楚。我们使用风洞和摄像机来测量次生水铝石扩散的 WV (TWV) 阈值和水铝石速度 (DV)。使用具有不同附属物（翅膀、刚毛、膜状气球和翅膀 + 刺）的七种 Calligonum 物种的水散孢子来确定可变风速（4、6、8 和 10 ms-¹）和四种 GS 下的 TWV 和 DV（水泥、沙子、壤土和砾石）。GS 和水铝石形态特征分别解释了 37.1% 和 18% 的水铝石 TWV。同时，WV、GS 和硬铝石形态特征解释了 62.4、13。分别为 6 和 3.2% 的 DV。TWV 呈上升趋势，DV 呈下降趋势，依次为水泥、砂、壤土和砾石表面。球形和轻质硬水铝石具有低 TWV 和高 DV，而有翼和重质硬水铝石具有高 TWV 和低 DV。我们的结果表明硬水铝石附属物的适应性特征可能是选择初级传播或次级传播的结果。硬水铝石二次扩散的机理对于理解退化沙丘的恢复和为恢复实践提供理论支持具有重要意义。而有翼和重水硬铝石具有高 TWV 和低 DV。我们的结果表明硬水铝石附属物的适应性特征可能是选择初级传播或次级传播的结果。硬水铝石二次扩散的机理对于理解退化沙丘的恢复和为恢复实践提供理论支持具有重要意义。而有翼和重水硬铝石具有高 TWV 和低 DV。我们的结果表明硬水铝石附属物的适应性特征可能是选择初级传播或次级传播的结果。硬水铝石二次扩散的机理对于理解退化沙丘的恢复和为恢复实践提供理论支持具有重要意义。