进境粮谷中携带苋属检疫性杂草籽风传播扩散距离的预测

风媒传播是外来杂草传播扩散的主要途径之一。我国进口粮谷中经常携带大量苋属杂草种子,这些种子质量轻,在卸货、运输等过程中存在风传播扩散风险。本文以3种重要苋属检疫性杂草,即长芒苋、西部苋和糙果苋种子为材料,通过测定其在可能撒漏高度范围和撒漏点风速范围内的垂直沉降速度和水平扩散距离,预测苋属3种检疫性杂草在装卸及运输过程中风传播扩散范围。结果表明在风速为35 m/s,种子释放高度为35 m时,长芒苋、西部苋和糙果苋3种杂草种子的最远扩散距离分别为57.75 m、111.68 m和114.33 m。

Prediction of wind dispersal distance of quarantine Amaranth seeds in imported grain

Wind dispersal is one of the main ways of spreading for exotic weeds.A lot of weed seeds of Amaranthus were carried in imported grain.These lightweight seeds were easily spread by wind during loading and unloading and transportation of grain.In this study,the vertical sedimentation velocity of seeds from three Amaranthus species,A.palmeri,A.rudis and A.tuberculatus,were measured and the dispersal distance at different wind speed and the possible leakage height of grain were calculated.The resuits showed that the maximum dispersal distance of A.palmeri,A.rudis and A.tuberculatus were 57.75 m,111.68 m and 114.33 m,respectively,at wind speeds of 35 rn/s and release height of 35 m.