The exotic honey locust (Gleditsia triacanthos) is often planted as ornamental tree in urban parks. In Hungary, it occasionally escapes cultivation, in other countries it has already become invasive, and thus, further spread cannot be ruled out. The production of copious long-lived seeds may contribute to its invasiveness. We investigated the soil seed bank of honey locust growing in urban parks of Budapest (Hungary). Soil samples of 1200 cm³ were taken under the canopy of 48 solitary female trees, seeds were extracted by washing, and their viability was assessed by germination test following scarification. For each tree, trunk circumference and level of park maintenance were recorded. Seed bank density varied between 0 and 500 seeds/m² and in 17 out of 48 cases, it exceeded 100 seeds/m². Larger trees tended to form better-developed soil seed bank than smaller ones, yet the level of park maintenance has a much stronger effect: trees in neglected parks produced five-times higher density on average than those in perfectly managed parks (126.4 and 24.5 seeds/m², respectively). For a better understanding of the species’ invasion risk, detailed seed ecological studies are needed and to prevent its further spreading, a more careful treatment of its litter is recommended.

中文翻译：

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树木大小和公园维护对城市绿地外来树皂角土壤种子库的影响

异国情调的刺槐（Gleditsia triacanthos）经常作为观赏树种植在城市公园中。在匈牙利，它偶尔会逃脱栽培，在其他国家它已经成为侵入性的，因此不能排除进一步传播。大量长寿种子的产生可能有助于其侵入性。我们调查了在布达佩斯（匈牙利）城市公园生长的刺槐的土壤种子库。在48棵孤雌树的树冠下采集1200 cm ³的土壤样品，通过洗涤提取种子，并通过划痕后的发芽试验评估其活力。对于每棵树，记录树干周长和公园维护水平。种子库密度在 0 到 500 粒/m ^{2之间变化}48例中有17例超过100粒/m ²。与较小的树木相比，较大的树木往往会形成更发达的土壤种子库，但公园维护水平的影响要强得多：被忽视的公园中的树木平均产生的密度是管理完善的公园中树木的 5 倍（126.4 和 24.5 颗种子） /m ²）。为了更好地了解该物种的入侵风险，需要进行详细的种子生态学研究并防止其进一步传播，建议对其垃圾进行更仔细的处理。