Based on the complex network method to build the 2001—2021 global copper trade network to describe its evolution characteristics, QAP(quadratic assignment problem) analysis was used to explore the impact of factors.It is found that the global copper trade network has a small-world character, and in part, Germany, China, the United States and Italy are the core nodes, in terms of influencing factors, the proximity of countries and the gap of economic development level will promote the copper trade significantly, and the larger the geographical and institutional distance will restrain the copper trade, the index of economic freedom, population and use of the same language will not have a significant impact. In view of this, it is suggested to strengthen cooperation with neighboring regions, increase R&D investment in technological innovation, and ensure the security and stability of China’s copper supply chain.
| 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 |