Uniqueness evaluation indicators for woody plant communities in urban park green spaces based on importance value: a case study in Qingdao city

Abstract There is a lack of objective evaluation indicators and methods for comparing the uniqueness of plant communities in different urban parks. In this study, we propose two uniqueness evaluation indicators for woody plant communities in urban parks based on the ecological importance value (IV): the mean non-overlapping IV (MNIV) and the local contribution to beta diversity based on IV (LCBD1). Subsequently, we investigated and evaluated the diversity and uniqueness of woody plant communities in eight hill parks (numbered Parks 1‒8) in Qingdao. A total of 101 woody plant species were found, with an average of 23.88 ± 5.96 species found in each hill park. The Shannon‒Wiener index and Pielou index of woody plants in Qingdao hill parks were in the range of 2.54‒3.40 and 0.94‒0.98, respectively. The results of MNIV, LCBD1, principal coordinate analysis and cluster analysis all indicate that Park 4 and Park 8 are the two most unique woody plant communities among the eight Qingdao hilltop parks. There was a very significant (P < 0.01) positive correlation between MNIV and LCBD1. MNIV and LCBD1were significantly (P < 0.05) negatively correlated with the IV of Pinaceae plants and significantly (P < 0.05) positively correlated with the IV of Anacardiaceae, Cannabiaceae, and Ginkgoaceae plants. In conclusion, this study offers indicators and methods for assessing the uniqueness of woody plant communities in urban parks and other green spaces. This is a valuable contribution to the research and evaluation of park green spaces.