Ge Xiuli, Li Xinxin, Han Ruifu, Zhang Shuping, Jiang Chunming
Department of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250100, China.
Academy of Life Sciences, Shandong University, Qingdao, 266000, China.
Sci Rep. 2025 Aug 1;15(1):28128. doi: 10.1038/s41598-025-09702-8.
Urban wilderness has gradually emerged as a hot spot for urban ecological research due to its crucial role in maintaining urban ecosystem services and protecting biodiversity. Compared to natural areas, urban wildnesss are more susceptible to invasions by alien species, which pose a threat to the functionality of the urban ecosystem. Currently, our understanding of biodiversity within various types of urban wilderness is not comprehensive, and the laws governing biodiversity changes due to alien species invasions remain unclear. This study focuses on an abandoned grassland community on a campus in northern China, which has been invaded by the alien weed Gaura parviflora. The study measured the characteristics of the aboveground community and the soil seed bank, comparing and analyzing species composition, plant/seed density, species diversity, and similarity at different levels of invasion (uninvaded, moderately invaded, severely invaded). The findings indicate that the uninvaded abandoned grassland community is rich in species (with 32 species) and has significant recovery potential (with an average seed density of 11,671 seeds per square meter). The community harbors multiple alien invasive species both aboveground and within the soil seed bank, and its succession process is influenced by biological invasions and human disturbances. The invasion by G. parviflora alters the species composition of both the aboveground community and the soil seed bank, resulting in a significant increase in plant density within the aboveground community. Its impact on the soil seed bank varies with soil depth, leading to a notable decrease in seed density in the 0-5 cm layer compared to the 5-10 cm and 10-15 cm layers; while the Shannon-Wiener biodiversity index for the 0-5 cm and 10-15 cm layers is lower than that of the uninvaded and severely invaded plots. This study reveals that the campus abandoned grassland community faces a high risk of biological invasion, and the invasion by G. parviflora has a more significant impact on the soil seed bank than on the aboveground community, which could lead to substantial changes in community species composition and a loss of biodiversity in the soil seed bank. It is therefore strongly recommended that greater attention be given to the impact of biological invasions on seed banks within the management of campus wild ecosystems.
城市荒野因其在维持城市生态系统服务和保护生物多样性方面的关键作用，逐渐成为城市生态研究的热点。与自然区域相比，城市荒野更容易受到外来物种的入侵，这对城市生态系统的功能构成了威胁。目前，我们对各类城市荒野中的生物多样性的了解并不全面，且外来物种入侵导致生物多样性变化的规律仍不明确。本研究聚焦于中国北方某校园内的一个废弃草地群落，该群落已被外来杂草小花高代花入侵。研究测量了地上群落和土壤种子库的特征，比较并分析了不同入侵程度（未入侵、中度入侵、重度入侵）下的物种组成、植物/种子密度、物种多样性和相似性。研究结果表明，未入侵的废弃草地群落物种丰富（有32种），具有显著的恢复潜力（平均种子密度为每平方米11671粒种子）。该群落地上和土壤种子库中都存在多种外来入侵物种，其演替过程受到生物入侵和人类干扰的影响。小花高代花的入侵改变了地上群落和土壤种子库的物种组成，导致地上群落植物密度显著增加。其对土壤种子库的影响随土壤深度而异，与5-10厘米和10-15厘米土层相比，0-5厘米土层的种子密度显著降低；而0-5厘米和10-15厘米土层的香农-威纳生物多样性指数低于未入侵和重度入侵地块。本研究表明，校园废弃草地群落面临着较高的生物入侵风险，小花高代花的入侵对土壤种子库的影响比对地上群落的影响更大，这可能导致群落物种组成发生重大变化以及土壤种子库生物多样性丧失。因此，强烈建议在校园野生生态系统管理中，更多关注生物入侵对种子库的影响。
