Urban rail transit in China has entered a new stage of transforming from "incremental expansion" to "stock optimization". This requires renovating existing lines, which poses a huge demand for funds and a high standard for longterm sustainability. Therefore, it is important to develop an investment and financing mechanism that matches the renovation needs and ensures the highquality development of urban rail transit. However, there is a lack of comprehensive and unified guidance for different types of renovation projects and various stakeholders. There is also an urgent need for theoretical research to support the innovation of investment and financing modes. This paper analyzes the experiences of typical cases in London, Japan, Beijing, Shanghai, Shenzhen, and Tianjin. Based on the economic, cyclical, and multibody characteristics of the projects, this paper proposes a grading and classification system for investment and financing, and constructs a mechanism that integrates financial subsidies and incentives with the stock of assets and new investment. This study can provide a reference and basis for improving the top-level design of renovation projects and forming a multi-principal synergistic investment and financing mechanism system for the medium and long term.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |