Does the Distance from the Formal Path Affect the Richness, Abundance and Diversity of Geophytes in Urban Forests and Parks?

Geophytes are a characteristic element of deciduous forests in the temperate zone, as well as a common component of urban green spaces due to their early flowering and high decorative value. Nevertheless, in urban areas, geophytes are constantly threatened by recreational activities, especially in parks where intensive trampling occurs. In this study, we tested the effect of the distance from formal paths on the species richness, abundance and diversity of geophytes in relation to habitat conditions in urban forests and parks. We established a total of 400 plots (1 m x 1 m) located close (CL) to and further (FU) from paths in 10 forests and 10 parks in Krakow, southern Poland, in spring 2022. We recorded 23 species from nine groups of geophytes forming different underground storage organs, i.e., bulbs (B), hypocotyl bulbs (HB), rhizomes (RH), runners (RU), runners and rhizomes (RU-RH), runner-like rhizomes (RL-RH), runners and runners with tuberous tip (RU-TU), runners and shoot tubers (RU-ST) and root tubers (RT). The differences in the number, share and cover-abundance of geophytes between the CL and FU plots were statistically insignificant. In contrast, the total number, share and cover-abundance of geophytes were significantly higher in forests than in parks. Additionally, the share and cover-abundance of RH and RT were significantly higher in forests than in parks. Moreover, in CL plots in forests and parks, the cover-abundance of RH and RT were negatively correlated with soil compaction. Urban forests provide a high abundance of RH, RU-RH and RT, while parks support a high abundance of BU. To protect forest geophytes in urban forests and parks, it is recommended to limit trampling and soil eutrophication, as well as reduce the increase in soil pH along paths.

Automated summary

The distance from formal paths has little effect on the species richness, abundance, and diversity of geophytes in urban areas. Geophytes in forests have significantly higher total number, share, and cover-abundance compared to those in parks. The share and cover-abundance of certain types of geophytes, such as rhizomes and root tubers, are also higher in forests. Urban forests are rich in rhizomes, runner-like rhizomes, and root tubers, while parks have a higher abundance of bulbs. Protecting forest geophytes in urban forests and parks requires limiting trampling, soil eutrophication, and the increase in soil pH along paths.