Abstract Urban ecosystems provide green landscapes that are important to global biodiversity conservation. In tropical urban ecosystems, exotic plants are widely used in landscaping and this can have several negative effects on the native plant and pollinator communities. Here, we aimed to investigate the origin (native or exotic to Brazil, and native or exotic to the phytogeographic dominium where the urban space is inserted), sexual and reproductive systems and fruiting of tree species occurring in 17 urban green spaces in the city of Recife, Pernambuco, located in the northeastern Brazilian Atlantic forest. A total of 114 tree species were registered in the urban green spaces, 78 out of them were observed for fruiting. Overall, 49.1 % of the species are native to Brazil and 50.9 % are exotic, while 86 % do not occur naturally in the northeastern Brazilian Atlantic forest. In terms of abundance of individuals, these values were 37 % native, 63 % exotic and 80.5 % not occurring in the northeastern Brazilian Atlantic forest. Most of the species, native or exotic, are hermaphrodite and self-incompatible (i.e. obligatory cross-pollinated). From the 78 species observed for fruiting, 77 set fruits, 43.7 % had sub-annual pattern; all exotic species (43 spp.) set fruits, even the 13 exotic species that are self-incompatible. Our results reveal that factors such as the high use of exotic species that successfully set fruits in tropical urban green spaces may indicate risks for plant-animal interactions (e.g. pollination; dispersion), threaten the reproductive success of native plant species, increase the risk of biological invasion, and consequently impair the maintenance of biodiversity. We suggest that decision makers pay attention and consider the impacts of using exotic plant species in the dynamic of tropical urban ecosystems.

中文翻译：

---

热带城市绿地中外来树木的高度丰富：生殖系统、结果和对本地物种的相关风险

摘要 城市生态系统提供了对全球生物多样性保护很重要的绿色景观。在热带城市生态系统中，外来植物被广泛用于景观美化，这可能对本地植物和传粉者群落产生若干负面影响。在这里，我们的目的是调查原产地（巴西本土或外来的，以及插入城市空间的植物地理主导区的本土或外来的）、性和生殖系统以及出现在城市 17 个城市绿地中的树种的结果。累西腓，伯南布哥，位于巴西东北部大西洋森林。城市绿地共登记树种114种，观察结果78种。总体而言，49.1% 的物种原产于巴西，50.9% 是外来物种，而 86% 不是自然发生在巴西东北大西洋森林中。就个体数量而言，这些值分别为 37% 的本地、63% 的外来和 80.5% 的不在巴西东北大西洋森林中出现。大多数物种，无论是本地的还是外来的，都是雌雄同体且不自交（即强制异花授粉）。从观察结果的78个物种中，77个坐果，43.7%有亚年型；所有外来物种（43 种）都能结出果实，甚至是自交不相容的 13 种外来物种。我们的研究结果表明，诸如在热带城市绿地成功结出果实的外来物种的大量使用等因素可能表明植物-动物相互作用（例如授粉；分散）的风险，威胁本地植物物种的繁殖成功，增加风险生物入侵，从而损害生物多样性的维护。我们建议决策者注意并考虑在热带城市生态系统动态中使用外来植物物种的影响。