2. Influencing factors based on interaction mechanism

From the perspective of the influencing factors of the interaction mechanism, symbiosis is a phenomenon of mutual influence and interaction between the two symbiotic units of TCEE and TEHQD (Figure 3). Through various interactions, the symbiotic relationship between the two symbiotic units can generate a new energy or achieve energy transformation, namely symbiosis energy generation. The specific performance is the symbiosis unit's ability to improve. From the interactive influence of TCEE on TEHQD, energy input and the capital input factor are the main factors driving the two symbiotic coordination interaction. From the interactive impact of TEHQD on TCEE, coordination and innovation are the main factors promoting the symbiotic coordination and interaction between the two. It can be found that the total energy consumption, the number of hotel employees, and the original value of fixed assets of star hotels are the key attraction factors affecting the symbiosis from the perspective of the symbiotic interaction between TCEE and TEHQD. From the perspective of the symbiotic interaction between TEHQD and TCEE, the investment in fixed assets of tourism, the R&D expenditure of tourism, regional differences in passenger turnover, and the tourism greening contribution are the key attraction factors affecting the symbiosis.

**Figure 2.** Symbiotic interaction mechanism model of tourism's carbon emission efficiency (TCEE) and the tourism economy's high-quality development (TEHQD) in the Yellow River Basin.

**Figure 3.** Interactive mechanism model of tourism's carbon emission efficiency (TCEE) and the tourism economy's high-quality development (TEHQD) in the Yellow River Basin.
