【摘要】 降水与种子埋深是影响外来植物幼苗出土与早期生长的关键环境因素。为探究外来植物幼苗生长对于降水以及埋深的响应机制，以少花蒺藜草（Cenchrus pauciflorus）为材料，研究4种降水（A，首次降水30 mm，后续不再降水；B，首次降水30 mm，以后每隔5 d降水6 mm，总降水量60 mm;C，首次降水20 mm，以后每3 d降水6 mm，总降水量80 mm;D，首次降水10 mm，以后每1 d降水6 mm，总降水量100 mm）及8种埋深（0、0.5、1、3、5、7、9、13 cm）处理对少花蒺藜草幼苗出苗过程及生长情况的影响。结果表明：（1）埋种深度显著影响少花蒺藜草种子的出土过程，少花蒺藜草的出苗时间及达到出苗高峰的天数均随着覆土厚度的增加而推迟，且出苗高峰的出苗数呈现出先上升后下降再上升的变化规律；（2）初次降水量对浅层埋深（≤3 cm）下少花蒺藜草幼苗的出土时间产生影响，而总降水量的多少对深层埋深（≥5 cm）下少花蒺藜草种子幼苗出土起调控作用；（3）各降水处理下少花蒺藜草幼苗的株高、地上地下生物量以及根冠比均在埋深1 cm时达到最大值，埋深9 cm时出现最小值，且总降水量越多，上述指标的情况越好；（4）少花蒺藜草幼苗的根长在埋深0 cm时达到最大值，埋深为9 cm时呈现最小值。少花蒺藜草种子的萌发及后续幼苗的生长在浅层埋深（≤3cm）的环境下有更好的表现，而过深的埋深则不利于其萌发及生长。由此，提出以下防控策略：通过深翻的方式来抑制少花蒺藜草种子的萌发；或在雨季来临后，对少花蒺藜草入侵严重区域喷洒除草剂，进而消耗少花蒺藜草种子库；或通过合理间作其他竞争力强的植物，消耗土壤水分，以此限制少花蒺藜草的生长空间。更多还原

【Abstract】 Precipitation and seed burial depth are the key environmental factors affecting the emergence and early growth of exotic plant seedlings. To explore the response mechanism of the growth of exotic plant seedlings to precipitation and burial depth, in this paper, Cenchrus pauciflorus was used as the experimental material to study four types of precipitation respectively. A, first precipitation of 30 mm, no subsequent precipitation. B, first precipitation of 30 mm, subsequent precipitation of 6 mm every 5 days Total precipitation 60 mm. C, first precipitation 20 mm, subsequent precipitation 6 mm every 3 days, total precipitation 80 mm and D, first precipitation 10 mm, subsequent precipitation 6 mm every 1 day, The effects of total precipitation of 100 mm and eight burial depths(0, 0.5, 1, 3, 5, 7, 9 and 13 cm) on the emergence process and growth of C. pauciflorus seedlings. The results show that:( 1) The depth of seed burial significantly affects the emergence process of C. Pauciflorus seeds. The emergence time of C. pauciflorus and the number of days reaching the peak of emergence are both delayed with the increase of soil cover thickness, and the number of seedlings at the peak of emergence shows a changing pattern of first increasing, then decreasing, and then increasing again.(2) The amount of initial precipitation affects the emergence time of C. Pauciflorus seedlings at shallow burial depth （≤3 cm）, while the total precipitation plays a regulatory role in the emergence of C. pauciflorus seeds and seedlings at deep burial depth （≥5 cm）.(3) Under each precipitation treatment, the plant height, aboveground and underground biomass, and root-crown ratio of the seedlings of C. pauciflorus reached the maximum value at a burial depth of 1cm and the minimum value at a burial depth of 9 cm. Moreover, the higher the total precipitation, the better the growth of the above indicators. The root growth of the young C. pauciflorus seedlings reached its maximum value at a burial depth of 0 cm and its minimum value at a burial depth of 9 cm. The germination of C. pauciflorus seeds and the growth of subsequent seedlings perform better in a shallow burial depth （≤3 cm）, while a burial depth that is too deep is not conducive to their germination and growth. Therefore, the following control strategies are proposed: Suppress the germination of C. pauciflorus seeds by deep ploughing; Or after the rainy season arrives, spray herbicides on areas severely invaded by C. pauciflorus, thereby consuming the C. pauciflorus seed bank. Or by rationally intercropping other competitive plants to consume soil moisture, the growth space of the low-flowered C. pauciflorus can be restricted.更多还原