Abstract:

Aim: Shanghai has been acknowledged for its remarkable achievement in accommodating a dense population and effectively utilizing its land. However, the native plant species within the city have faced significant disruptions due to human interference, resulting in a decline in species diversity. Nevertheless, Shanghai boasts an area of immense botanical value, featuring a wide array of cultivated plants. In fact, it stands as the only region in China where the number of cultivated plants exceeds that of native plants. In order to safeguard the diversity of plants and promote the sustainable utilization of these invaluable botanical resources in Shanghai, especially in preparation for the forthcoming comprehensive regional biodiversity survey, we have taken on the task of updating the checklist of Shanghai vascular plants.

Methods: This paper utilized the plant specimens and image information collected during extensive field surveys conducted over the years. Furthermore, collections and literature data were incorporated to supplement the cataloging data of species. Especially, the time when species were first discovered or recorded in Shanghai was determined based on the original records found in literature and specimens. Additionally, the names and systems of the included species were revised based on the classification revision literature of specific taxa and the latest advancements in molecular systematics.

Results: The resulting checklist included a total of 4,126 species, infra-species taxa and cultivars of vascular plants. This included 1,238 wild and escaped plants and 2,888 cultivated plants from 211 families, 1,176 genera, and 2,782 species with 38 subspecies, 107 varieties, and 5 forms. Additionally, there were 1,194 cultivated varieties listed. The number of taxa included in the current version of the list has increased by 914 compared to the checklist of Shanghai vascular plants (2013 version), largely due to the inclusion of newly cultivated varieties. While only 34 new wild species were added, native plants saw an even smaller increase, with only 5 new species included. The survey revealed that 92 native plants were no longer present in the area, which suggested that the number of native plants in Shanghai has declined for the first time. This underscores the importance of conducting specialized surveys of native plants in Shanghai, particularly for those that have not been observed in several years. The history of the substantial increase in cultivated plant diversity in Shanghai was relatively short, spanning only 40 years. The number of original species of cultivated plants started to increase in 1980, and since 2010, there has been a significant surge in cultivated plants, with the majority being artificially selected varieties. This trend was largely influenced by factors such as socioeconomic status, human preferences, and cultivation management practices. The updated vascular plant checklist adopted new systems of delimitation and arrangement of plant families, which were primarily based on molecular phylogenetics. The reasons and references for scientific name changes were also provided. Additionally, an online dataset of the checklist was readily available to the public in Excel format, facilitating easy access, retrieval, and utilization of the data.

Conclusions: Based on our results, we recommend that field surveys continue, with a particular focus on species missing from the recent survey. Additionally, since more than half of the newly added alien plants are invasive species, it is crucial to strengthen the investigation and monitoring of these plants.

Key words: species inventory, vascular plants, Shanghai, wild plants, cultivated plants