Desiccation cracks act as natural seed traps in flood-meadow systems
Desiccation cracks act as natural seed traps in flood-meadow systems
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DOI：
10.1007/s11104-010-0350-1
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发表时间：
2010-08-01
期刊：
影响因子：
4.9
通讯作者：
Donath, Tobias W.
中科院分区：
文献类型：
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作者：
Burmeier, Sandra;Eckstein, R. Lutz;Donath, Tobias W.
干燥裂缝是富含粘土的土壤在干燥条件下通过土壤收缩形成的自然现象。我们的目的是测试这种裂缝的种子捕获潜力，并评估其对种子库形成的影响，在洪水草甸生态系统。我们记录了永久地块上的裂缝模式，并分析了裂缝沿着和附近的土壤种子含量。通过裂缝的种子转运进行了测试与标记重捕实验，和后诱捕种子的命运进行了测试与埋葬实验。在连续的干燥期，大多数裂缝在相同的位置重新张开。沿着裂缝，大多数种子被发现在10-20 cm的深度，而邻近裂缝的大多数种子被发现在0-5 cm的深度。大多数的种子发现在浅的深度附近的裂缝属于物种，也存在于地上植被，而这一比率始终低于50%沿着干燥裂缝。标记-再捕获实验证明了种子通过干燥裂缝的垂直迁移。诱捕后种子的命运不同的物种和埋藏深度，随着深度的增加，增加生存的趋势。我们的结论是，干燥裂缝作为天然种子陷阱，促进种子库的形成，从而影响植物群落动态的洪水草甸系统。
Desiccation cracks are a natural phenomenon of clay-rich soils that form via soil shrinkage during dry conditions. Our aim was to test the seed trapping potential of such cracks and assess its impact on seed bank formation in a flood-meadow ecosystem. We documented crack patterns on permanent plots and analysed the soil seed content along and adjacent to cracks. Seed translocation via cracks was tested with a mark-recapture experiment, and post-entrapment seed fate was tested with a burial experiment. Most cracks re-opened in the same positions in consecutive dry periods. Along cracks, most seeds were found in 10-20 cm depth, whereas adjacent to cracks most seeds were found in 0-5 cm depth. The majority of seeds found in shallow depths adjacent to cracks belonged to species that were also present in the above-ground vegetation, whereas this rate was always under 50% along desiccation cracks. The mark-recapture experiment gave evidence for vertical seed translocation through desiccation cracks. Post-entrapment seed fate differed between species and burial depth, with a trend towards increasing survival with increasing depth. We conclude that desiccation cracks act as natural seed traps, foster seed bank formation and thus influence plant community dynamics in flood meadow systems.