Landscape characteristics and evolution of Qingyuan Mushroom Cultural System, Zhejiang Province

As the birthplace of the artificial cultivation of Lentinus edodes, Qingyuan County in Zhejiang Province has been considered a site of China Nationally Important Agricultural Heritage Systems. Moreover, Qingyuan Mushroom Cultural System in Zhejiang Province is applying for the Globally Important Agricultural Heritage Systems (GIAHS) site. Agricultural heritage is the crystallization of the ancient people's wisdom paired with the wealth of modern society. Agricultural heritage landscape is the most direct expression of agricultural heritage in modern life. Studying landscape characteristics and evolution helps us understand the regional landscape and its influencing factors, so as to implement effective protection and development strategies for heritage sites. In this paper, satellite images from Landsat in 1991, 2001, 2010 and 2018 were obtained and combined with field research. Firstly, vegetation indices and a random forest classifier were used to study the current status, characteristics and structure of landscape of the heritage site of traditional mushroom cultivation system. Then, a land use transfer matrix was used to analyze the direction of evolution and rules of different landscapes. Finally, the related forestry policies and meteorological factors were chosen to study the possible driving factors of the area changes of landscapes from 1991 to 2018. The results show that: 1) The landscape types of heritage sites include forest, cultivated land, residential land and bodies of water, among which forest is the dominant landscape type, with its area reaching 1 643.23 km² and accounting for 86.61% of the total area. The area of cultivated land, residential land and water is 213.72 km², 33.76 km² and 6.54 km² respectively, accounting for 11.26%, 1.78% and 0.34%, respectively. 2) The traditional cultivation system landscape is rich in high mountains, dense forests, streams and mushroom resources, forming a vertical landscape structure of "river-village-terraced-forest", and has plenty of unique mushroom cultural landscapes such as the Xiyang Temple, Wu Sangong Shrine and ancient mushroom shed. 3) From 1991 to 2018, the forest area in the heritage sites increased by 139.28 km² (7.34%), the cultivated land decreased by 154.53 km² (8.15%), the residential land increased by 11.86 km² (0.63%), and the water bodies increased by 3.48 km² (0.18%). 4) Landscape change is closely related to relevant policies. At the end of the 20th century, deforestation was prevalent in heritage sites and the forest coverage decreased from 79.27% to 77.97%. Since the 21st century, the mountains closure for forestation and ecological forestry construction has achieved remarkable results, with forest coverage rising from 77.97% to 86.61%. The policy of Grain for Green and increased urbanization promoted the decrease in cultivated land and the expansion of residential land, respectively.