Abstract:The planting area of cash crops represented by orchards has expanded rapidly, which has not only obtained certain economic benefits, but also caused a series of ecological and environmental problems. Carrying out research on orchard expansion and its evolution characteristics is an important part of helping the sustainable development of orchards. Taking Qixia, Laiyang and Haiyang, the main apple producing areas in Yantai City, Shandong Province as the research areas, based on the land use data extracted by the linear spectral mixed decomposition method, the changes in the orchard planting area in the study area from 1998 to 2019 were analyzed. Combined with expansion intensity, expansion rate and landscape pattern index, the characteristics and laws of local orchard expansion and evolution were analyzed. The results showed that during the study period, orchard showed a continuous expansion trend, and it was clearly divided into two stages: rapid expansion (1998—2010) and stable expansion (2010—2019). The orchards were expanded by 409.25km2 and 684.71km2 respectively;in addition, about 68.11% of the orchard expansion occurred in Qixia, which led to the formation of an agricultural economic development model based on orchard planting. From 1998 to 2019, the main sources of orchard expansion were forest and cultivation, and their contribution rates were about 23.55% and 55.52%. Single cropping was the main source of cultivation, and the contribution rate of orchard expansion was as high as 42.51%, while bare land contributed the least. After 2010, the expansion of orchard in the study area was changed from filled to scattered, the degree of aggregation of the orchard structure was decreased, and the degree of fragmentation was increased. In addition, the expansion of orchard mainly occurred in high altitudes and mountains, and priority was given to expansion. The area had sufficient climatic resources and excellent natural geographical conditions, which were conducive to the growth and development of apple trees. When the orchard was expanded to a certain scale, it would be limited by factors such as altitude, slope and rural labor, and gradually expanded to areas with relatively poor terrain conditions, which may cause the orchard’s unbalanced income and expenditure and greater potential water and soil environmental risks, the local government should pay attention. The overall planting suitability of orchard planting area in Qixia was high, and the external environment for orchard growth and development was good, especially climatic condition. Affected by soil conditions, the external input of fruit tree planting areas in Laiyang and Haiyang was relatively large.
