作 者 ：沈有信, 刘文耀
期 刊 ：植物生态学报 2004年 28卷 6期 页码：768-772
关键词：紫茎泽兰；长久性土壤种子库；与植被关系；水平分布；垂直分布；
Keywords:Eupatorium adenophorum, Persistent soil seed bank, Vegetation relationships, Horizontal distribution, Vertical distribution in soil,
摘 要 ：具有长久性土壤种子库的植物在适应多变的生境和不良的生长条件方面具有优越性。于紫茎泽兰（Eupatorium adenophorum）的主要萌发时段后（7月到次年的4月间）在云南的5个地点采集了共１９个不同植被覆盖下的土壤种子库样本，萌发实验结果表明，紫茎泽兰具有长久性的土壤种子库，其在云南的不同生境的土壤中广泛分布，所有19个样地中都有长久性的紫茎泽兰种子。 0～10 cm土层的种子密度变动于47～13 806 ind.·m-2，平均为2 202 ind.·m-2。种子密度与样地内地表的紫茎泽兰间没有直接的联系，但与植被的覆盖状况有关，种子库密度由滑坡堆积物（47 ind.·m-2）到草地（801 ind.·m-2）到灌丛（2 349 ind.·m-2）到森林（3 255 ind.·m-2）间逐渐增加。种子在各种类型土壤的采样点间出现的频度为60%～100%。在土壤的垂直方向上，0～2 cm土层分布有较多的种子，2～5 cm土层次之，5～10 cm土层最少，其各层占总数的比例的平均值分别为56.1%、25.2%和18.6%。但值得注意的是，虽然紫茎泽兰的种子在5～10 cm 深的土层内的存在量占总量的比例相对较少，但如果折合成密度值，其量仍高达270 ind.·m-2，仍有形成危害的潜在可能。广泛分布且数量巨大的具有长久性特性的紫茎泽兰土壤种子库对各种防治措施的制订意义重大，它要求我们长远地、大尺度地考虑防治措施。
Abstract:Plants with persistent soil seed banks have advantages in stress and harsh environments. Soil samples were collected from 19 different soil sites with different vegetation at 5 locations across Yunnan, Southern China, at different times from July to April after the germination season of Eupatorium adenophorum seeds. Germination research results showed that E. adenophorum had a persistent soil seed bank. Its seeds distributed widely across soils in Yunnan and seeds were found at all 19 sample sites. Seed density in the 0-10 cm soil layer varied between 47-13 806 ind.·m-2 with an average of 2 202 ind.·m-2. The density did not show a direct relationship with the mother plant of E. adenophorum, but did show strong relationships with standing vegetation types. The density increased from 47 ind.·m-2 in newly deposited material of a slide to 801 ind.·m-2 under grass cover, to 2 349 ind.·m-2 under shrub cover, and the highest density of 3 255 ind.·m-2 under forest cover. Frequency of seeds identified from soil samples across all 19 soil types varied between 60%-100%. Vertically, seed density in the 0-2 cm soil layer was the highest, followed by the 2-5 cm layer, and the 5-10 cm depth had the lowest seed density. E. adenophorum seeds accounted for 56.1%, 25.2% and 18.6% of the total seeds in the three soil layers, respectively. Although the total percentage of seeds in the 5-10 cm layer was low, the total density was high (270 seeds·m-2) and, although not in the position of germination, had the potential for germination and being environmentally harmful. The wide distribution and high density of E. adenophorum in the soil seed bank have significant implications for any prevention and control measures, and we suggest that a long-term, large-scale approach should be taken to deal with the spread of E. adenophorum.