Seed banks in the soil play a role in the temporal continuity and succession of vegetation in urban vacant lots. Therefore, it is necessary to know the composition, abundance and dynamics of the seeds stored in the lots’ soils to understand their effect on spontaneously established urban plants. We hypothesized that soil seed banks in the urban vacant lots of Santiago, Chile, have a high abundance of seeds and an easily germinable bank of mainly exotic annual weeds. Additionally, 5 drivers (lot age, lot area, distance to urban centre, distance to urban boundary, and population density) were associated with the density of seed banks in the soil of urban lots. In 20 lots studied, 18 soil samples (150 cm³ per sample) were collected, 9 samples at a depth of 0–5 cm, and 9 samples at >5–10 cm. This seed bank was studied by seed germination in each of the soil samples. Thirty-eight species recorded in the seed banks were exotic (83.7% were European, Mediterranean or Eurasian) and only three native. Two species could be identified up to genus only. We recorded in total 2934 seedlings in the upper soil layer and 506 seedlings in the lower soil layer from the 20 lots analyzed. The species frequency in the upper seed bank was positively and significantly correlated with the frequency of the lower seed bank and with species frequency for above-ground vegetation. In the upper soil layer, our results showed that smaller lots located in the most densely populated neighborhoods contain more weed seed density in the soil than greater lots located in less densely populated areas. The rest of the factors evaluated were not associated with the density of the seed banks in the soil. The results indicate that research in seed banks in urban habitats should be expanded and deepened, since the seed banks are determinants in the spatio-temporal abundance and diversity of above-ground spontaneous urban lot flora.

中文翻译：

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拉丁美洲大城市空置地段的种子库很容易萌芽，并以外来植物为主

土壤中的种子库在城市空地中植被的时间连续性和演替中发挥作用。因此，有必要了解存储在土地土壤中的种子的组成，丰度和动态，以了解它们对自发建立的城市植物的影响。我们假设智利圣地亚哥的城市空置地上的土壤种子库拥有大量的种子，并且主要是外来一年生杂草易于发芽。另外，有5个驱动因素（地块年龄，地段面积，到城市中心的距离，到城市边界的距离以及人口密度）与城市地块土壤中种子库的密度有关。在研究的20个批次中，有18个土壤样本（150 cm ³每个样品），在0-5 cm深度处有9个样品，在> 5-10 cm处有9个样品。通过种子发芽在每个土壤样品中研究了该种子库。种子库中记录的38种是外来物种（欧洲，地中海或欧亚大陆占83.7％），只有三种。最多只能识别两个属。我们从所分析的20个批次中总共记录了2934棵上部土壤层的幼苗和506棵下部土壤层的幼苗。上种子库中的物种频率与下种子库的频率以及地上植被的物种频率成正相关且显着相关。在上层土壤中 我们的研究结果表明，位于人口最稠密地区的较小地块比位于人口较少地区的较大地块具有更高的土壤杂草种子密度。评估的其余因素与土壤中种子库的密度无关。结果表明，由于种子库是上述物种的时空丰度和多样性的决定因素，因此应扩大和深化对城市生境种子库的研究。-地面自发的城市植物群。