【摘要】 采用样方调查法,研究了毛乌素沙地臭柏(Sabinavulgaris)群落的种子产量、种子库及幼苗更新。结果表明:毛乌素沙地天然臭柏群落的球果丰富,约为3093. 83粒/m2,种子产量为9118. 5粒/m2,优良种子达2954. 4粒/m2。5种立地条件间的土壤种子库差异大、质量低,种子优良度最高的也仅为3. 7%。土壤种子集中分布于0 ~5cm土层内,并随着土壤深度增加,优良种子数由0~5cm的30. 52粒/m2减少到5~10cm的1. 3粒/m2。5 种立地中当年幼苗数的平均值仅为7. 98株/m2,最高的(A类立地)为14. 7株/m2,仅占表土优良种的30%左右,最低的(D类立地)已经丧失了更新能力。臭柏群落内种子更新苗少,而且种子更新集中在少数滩地小生境中。种子库小、质量差、更新环境的丧失是限制臭柏群落天然更新与拓展的主要因子。更多还原

【Abstract】 Seed yield, seed bank and seedling regeneration of Sabina vulgariscommunity were investigated in Mu us sandland by random sampling .Results showed that: Heavy cone was observed in the Sabina vulgariscommunity of Mu us sandland with as much as 3093.83 per square meter. It was concluded that seed yield was about 9118.5 per square meter, and the fine seeds all contributing to regeneration in the communitywere2954.4 per square meter. The differences of the soil seed banks were so obvious among five site types, and seed quality was very poor. The highest percent of fine seeds was only 3.7%. In the soil seed bank, the seeds were distributed mainly in the 0～5cm layer of soil. The numbers of fine seeds declined gradually with the increase of soil depth. We found there were a few annual seedlings in five site types, about 7.98 per square meter. The site which had the highest density was 14.7 per square meter,accounted 30 percent of fine seeds in the surface soil. The site with the lowest density had lost the ability to renovate. Few seedlings exist under Sabina vulgariscommunity, and seed regeneration mainly distributed in few mic-habitats, such as bottomland. Small seed bank, poor seed quality and the comedown of regeneration entironment were primary factors limiting regeneration and development of naturalSabina vulgariscommunity.更多还原