1. Based on the symbiotic system theory

Based on the symbiotic system theory, a symbiotic interaction mechanism model of tourism's carbon emission efficiency (TCEE) and the tourism economy's high-quality development (TEHQD) was established by taking TCEE and TEHQD as two main symbiotic units (Figure 2). TCEE can evaluate the development quality of tourism from the dual perspectives of economy and ecology, and the TEHQD is based on a tourism economic development concept of "innovation, coordination, green, open and sharing", which also involves many aspects such as economy, ecology, and tourism's development quality. Therefore, there is a quality parameter compatibility between the two symbiotic units. That is, some attributes of the symbiotic units are related, so it can be judged that there is a symbiotic interaction between the two units. The symbiotic interface is the energy transmission channel between symbiotic units, and the transmission of different types of energy requires different symbiotic interfaces. Because the symbiosis between TCEE and TEHQD is relatively complex, involving multiple symbiotic internal and external environments, such as politics, economy, culture, society, and ecology, the tourism market, as the result of the comprehensive effect of TCEE and TEHQD, can represent the comprehensive interaction between the two symbiotic units and, thus, can serve as the symbiotic interface of the symbiotic interaction mechanism.
