GIAHS sites designated by FAO have increased to 62 in 22 countries at present. On the whole, even though many AHSs have paid attention to tourism development, tourism is still in the early stage at AHSs. Many AHSs have shown high levels of interest in tourism and plenty of examples can be found in different countries.

Japan set some good examples of trying to attract domestic visitors, combined with the experience of rural tourism development. The local farmers of mountain and coastal rural landscapes in Kanazawa Noto Peninsula increased71% after the heritage designation in 2011, improving the labor force of tourism development (Tong et al.,2017). In Sado’sSatoyama of Japan, an activity named “Sado’s Hiking” was organized and tourists were allowed to closely view the crested Ibis birds and the related ecological environment, under the supervision of experts and management personnel of AHSs, so as to ensure that the tourists would not disturb the Crested Ibis and other wildlife (Lu and Wang,2016). In 2014, the Traditional Tea-grass Integrated System in Shizuoka was selected as a GIAHS, and then a series of activities such as tea garden eco-tours and tea garden eco-festivals were launched. The tourism map was designed to clearly indicate the factory, manor, tea bar and other places related to tea culture, which was welcomed by the tourists. Visitors can not only enjoy the ancient tea farming methods, but also put themselves into the cultivation activities of “tea pasture farming”. A tea museum was also set up in Shizuoka to show its long history of tea culture, popularize tea knowledge and conduct academic exchange activities (Tao and Zhang, 2017). Many other countries are considering tourism in AHSs as an economic engine. The Korean TraditionalGudeuljang Irrigated Rice Terraces in Cheongsando has 11 highway tourist routes for sightseeing, and through the self-guided tours, tourists can meet the local residents on the coastal roads and experience the local food and tradetional culture (Lim, 2015).At the Gil exhibition held in Jeju Island, the batdamAgricultural Heritage System of the GIASH of Jeju Island was displayed, and most of the tourists showed a strong interest in the local agricultural cultural heritage. They were invited to take field trips with researchers, and introduced to the changes of the crops in Jeju Island, the history of the rice and vegetable trade, etc. (Hiroyuki et al.,2018).The Qanat-based Saffron Farming System in Gonabad of Iran promoted tourism to cope with the threat of unemployment among the farmers, infertility of the soil and low yields. Tourists can not only enjoy the agricultural landscape (such as date palm trees, citrus orchards, terraces, etc.), but also obtain the knowledge and experience of the intangible agricultural cultural heritage (Farsani et al., 2019). The agricultural system of erwade oasis in Algeria vigorously developed eco-tourism, strengthening the production of jujube and increasing the opportunities to sell jujube and other fruits in different markets, which brought higher income to the residents, so as to attract and encourage young people to return from the city to the countryside (Bai et al., 2014). Specific traditional resources are the main attractions for tourists in the Masai grassland in Tanzania, where, local people built national parks and natural parks to attract tourists, set up cultural centers for tourists to experience the local culture, and also sold traditional handicrafts and decorations to tourists. In Tanzania, tourism has become an important alternative source of income for Masai (Kalavar et al., 2014).

European countries have paid plenty of attention to GIAHS in recent years and also to the related tourism. Chianti is one of the most famous rural tourism areas in Italy, and Lamole is the center of Chianti. In Lamole, the historical landscape is well preserved, and tourism is one of the main sources of income for local farmers. Local residents earn tourism income by providing accommodation and catering for tourists. According to the statistics of the National Bureau of Statistics, there were1286 beds (51.5% of the total) for tourists in the farmhouses in 2017, which were distributed in 81 farmhouses (Santoro et al., 2020).

In South America, tourism has also started to gain attention. In Chile’s Chilo Island, where the agricultural system is located, officials have set up new tourism routes, established rural travel agencies, vigorously promoted local tourism products, tourism services and cultural undertakings, made culture the driving force of local development, and encouraged cooperation among farmers, hotels and operators, so as to ensure the sustainable development and fairness of the tourism trade (Bai et al.,2014).

As one of the first countries to respond to the FAO GIAHS (Altieri and Koohafkan, 2007; Min and Sun, 2009; Min et al., 2011; Sun et al., 2019; Su et al., 2020a), China is leading the world in Agricultural Heritage System conservation and tourism development. With the initiative of China-NIAHS, 118 NIAHS were selected and named, distributedin29 provinces. Studies show that most of the GIAHS sites have developed tourism to varying extents, and some have attracted plenty of visitors with different kinds of tourism products. Some developed the rural tourism and pro-poor tourism, which provides different kinds of accommodations and souvenirs. The development efforts have reflected some regional differences, like tourism infrastructure, consumption patterns, degrees of government support and variations in the tourism products (Table 1). In eastern areas, tourism developed quickly but with more negative social and ecological impacts. In contrast, in the middle and western parts of the country, tourism has developed much slower, and its negative outcomes have been much less obvious than in the east (Sun et al.,2019).

With the development of China’s tourism, destinations have received much more attention ever since the “Whole Region Tourism Strategy” was proposed. Hence, agricultural heritage tourism was included in many places in China, even though some development modes are yet to be discussed. Cultural elements were emphasized in agricultural tourism with the formation of a special division of the Ministry of Agriculture and Rural Affairs, at the national level. At the local level, one focus has been on the relationship between culture and agriculture, which is good for agricultural tourism and the related tour products. The nationwide advocacy of tourism has two opposing influences. On one hand, it promotes the development of tourism; but on the other hand, it also brings many problems in the development.

It is a fact that many people can be attracted by a large cultural symbol, and the Agricultural Heritage System is one of those newly recognized cultural symbols. No matter what intention the policy makers have for maintaining the thriving tourism in the AHSs, it would bring the positive and also the negative impacts, just like tourism in any other heritage sites. The differences lie in the features of the Agricultural Heritage System itself, especially in the threats that the Agricultural Heritage System faces, which show a kind of universality and uniqueness. Obviously, some threats have not been given enough attention, while others have been misunderstood.

The neglect of the multi-functionality of traditional knowledge and techniques is everywhere, leading to the difficulties of traditional agricultural system inheritance in the fast-growing modern society. The shallow understanding of traditional agricultural intelligence has also originated from the weakening of the multi-functionality of the Agricultural Heritage System, which leads to an inappropriate tourism development direction and product development. With the deepening of people’s recognition of a healthy life and a safe future, the conversation of the functional diversity is getting easier among different interest groups, while the pressure of development and other driving strengths are still hindrances of the conservation policy and sustainable use approaches.

Some threats, like the outflow of rural labor and especially the young adults, bring lots of anxiety for the local heritage managers, and many researchers have mentioned the potential crisis this would bring to Agricultural Heritage System conservation (Min and Sun, 2009; Jiao and Min, 2017; Zhang et al., 2017; Min, 2018; Su et al., 2018; Su et al., 2020b). Recent research shows that the labor force is not actually a deadly threat for Agricultural Heritage Systems, since the farming time of the local farmer is flexible and the out-of-work farmers can still be engaged in the farming system during the critical periods of the farming process. This means the phenomenon of labor absence is periodic and the availability of multiple livelihood sources has enriched the farmer’s life without damaging the root of farming production itself. Tourism research has shown an interesting finding, that almost all farmers are using less than 10% of their time on the farming systems in the Rice-Fish system, Zhejiang Province, and the Hani Rice Terrace System, Yunnan Province, whether they are involved in tourism or not, and no matter how deeply involved they are (Wu et al.,2020). This fact indicates that tourism as an alternative livelihood approach would not have negative impacts on the time distribution, at least at the early stage of a heritage site like in Zhejiang and Yunnan, which were just designated on the FAO agricultural heritage list over approximately the past 10 years.

In fact, a threat ignored for a longtime is the educational system in rural areas. The young labor force’s long term residence in the heritage site, where the education system was very backward, cannot support the children’ school education in the agricultural sites. The long-time residence in the heritage site has not received the appropriate attention as the significance of the connection of the place with the people was ignored. Tourists are not supposed to be able to distinguish the service provided by a resident and an outsider, while the research shows a big difference between the local service and the industry service (Thetsane, 2019).

With regard to agricultural heritage tourism, more and more researchers are focusing on the mode of development (Sun et al., 2010;He and Min, 2013; Wang and Chen, 2017). The increasing number of tourists draws a blueprint at the destination which fulfills the needs of local managers and administrators, while the “number code” has failed to match the future expectation in an increasing number of cases of heritage sites.

It is not very easy to fully understand the relationship between the scenic spot mode and the whole region tourism mode, in that the latter was supposed to revolve around the unique orientation of scenic spots. The enthusiasm for scenic spots was embedded in the blood of tourism managers of the destinations, encouraged by the present national 5A grade scenic selections. Obviously, the willingness of national policy-making was distorted, and scenic spots were elevated too drastically at the local level. The direct consequence is that the enthusiasm for the spots never disappears, in contrast to the original dream as interpreted by the appeal of the destination.

In many AHSs, tourism was included in the rural background and considered as a small element within the whole region tourism development, which sounds like it would be no problem while the attraction emphasis is changing. With the intention of the attraction using some superficial agricultural elements, agricultural heritage tourism has missed its potential, which can only be found in the academic articles and constructed theories. Its driving strength was not only from the local government achievements, but its aesthetic appeal was not very well developed in the public view. In other words, as a way of simple, direct assessment, and without truly understanding the problems brought by agricultural heritage tourism, the identity building, the regional pride, the way of traditional intelligence lasting to the future, etc., only the “numbers and brands” are visible.

Some obvious problems, like the linkage of enterprises and local communities, seem like clichés but it is the most significant issue to cope with, at present and in the future. It is a challenge that the whole world is facing, since agriculture heritage system conservation is community-based and locally-centered, which requires the attention first at the local level, to be deeply involved in the development, and not just on the surface. Most studies on this issue have pointed out that the power relations among stakeholders are imbalanced, with the interests of locals much lower than those of the others like enterprises and governments (Shi and Sun,2016; Sun et al., 2019), while the weak engagement in practice (compared with the abundance of research outcomes) brings more disappointment when the community power was considered to be enhanced. As a result, many Agricultural Heritage Systems were included in theme parks, as tourists are assumed to enjoy the mode of experiencing agriculture through the artificially designed field play and tourists are supposed to get more satisfaction when some on-site farming experience activities are organized in a short time with a high intensity.

It is almost impossible when the policies related to tourism are used to talk about the empowerment of the local people. The top-down model is very useful when combined with the bottom-up, and the logic is so clear that few will be able to deny it, while under the situation of Chinese rural history and institutional customs, community is a new entity compared with the western style of power expression. The willingness to empower the locals and trying to find the best way of involvement was studied all over China and its attempt in Agricultural Heritage Sites has also been discussed theoretically (Li, 2015; Shi and Sun,2017). Scholars are trying to find the influential factors that hinder community involvement and whether this is the main obstacle to heritage conservation and tourist satisfaction (Shi and Sun, 2016; Su et al., 2018; Su et al., 2020b), and it turns out to be not very effective in practice.

Environmental conflicts during tourism development have been researched for a long time (Lee and Jan, 2015; Min, 2018), while in fact they tend to be overlooked when it comes to the tourism development process. More attention has been paid to natural heritage sites and the biodiversity reserves (Lei et al., 2013; Su et al., 2016; Ren et al., 2018; Ding et al., 2019), especially as it relates to the habitats of endangered species(Smith et al., 2011). Agricultural Heritage Systems are vulnerable to external interference, thus causing damage to the agricultural environment. For example, improper use of water resources will lead to the exhaustion of terrace water and influence the sustainability of the terraces. In some terrace areas, excessive tourism infrastructures, such as hotels and restaurants, were built which use too much water, so they should receive more attention otherwise the terrace will no longer remain.

The sustainable tourism criteria were developed at the global level, which shows the common understanding and knowledge of sustainable tourism development. Meanwhile, local cases provide the experience and approaches during the practical management process of tourism. Apparently, the global criteria and local approaches are connected andthe interactions would bring new understanding regarding sustainable tourism. GIAHS was intended to build the dynamic conservation and adaptive management mechanism in a bottom-up approach. It turned out, however, that the bottom-up approach was very hard to implement in China due to the customary and traditional understanding of diplomatic management. The traditional top-down approach is not conducive to mobilizing the enthusiasm of communityresidents. Therefore, a combination of the top-downapproachwith Chinese characteristics and the bottom-up approach advocated internationally plays an important role in the protection and management of Agricultural Heritage Systems in China. This is a good example of the combination of global and local experiences. The combination of global experience and local experience can also avoid prejudice, respect local traditions and apply local experience in a global standard environment, which would produce new understandings of the tourism development in Agricultural Heritage Sites.

According to the GSTC-D, many elements of the AHSs are very important, which is consistent with the previous case analysis of AHSs in China. Even in other countries, where there are indications that the formulation of global standards also combines the experiences of many places for AHS, several factors are particularly important, which fundamentally determine whether their tourism is sustainable. These factors are community participation, tourist management, resource utilization, environmental and ecological conservation, risk management, multi-stakeholder coordination, planning, and product design. Many studies have emphasized the community participation issues in AHSs, and this is also one of the main problems in most heritage sites, especially in some developing countries, like China. Empowerment is advocated while the results are not very good. Community participation is closely related to multi-stakeholder coordination. At present, the main contradiction is that the power of the Chinese community is relatively weak, while the strength of the government and enterprises is relatively strong. Therefore, determining how to improve the ability and effect of community participation needs to be a major focus. Tourist management is closely connected with community, product design and environment conservation. The education- and research-orientated tourism products were supposed to better involve the community and help in the environment conservation, as the carrying capacity would be one of the core elements of tourist management, and mass tourism would be difficult to control by the numbers. On the other hand, the education-and research-oriented tourism would try to promote the protection of agricultural heritage, excavate the connotation of agricultural heritage and transform the recessive heritage symbols into explicit tourism products. Basically, those tasks cannot be done without the involvement of the local community. A good planning strategy at the heritage sites would do well for the conservation and the management of the heritage sites, and emphasize the risk management and resource utilization, which is pretty significant in modern society. It is easy to understand that all those elements are connected and cannot be eliminated from agricultural heritage sustainable tourism development.