A review of conservation of rice terraces agriculture as agricultural heritage systems

Terraces are old agricultural field systems created by the ancestors according to the local terrain and which still perform their production function today. These land use systems clearly show the wisdom and abilities of human to adapting and to takinge advantages of the natural environment. Nowadays, the tillage and management experiences and traditional agricultural knowledge on terrace systems can offer important insights and reference pointss for the sustainable development of modern agriculture. With industrialization and urbanization, however, the limitations of terrace agriculture in production efficiency are more and more obvious, which has led to a series of natural and man-made environmental and societal problems due to the terrain limits for using farm machines and overwhelming development of tourism. These negative effects have led to the near collapse of terrace agriculture. Thus, a series of research projects on the protection of terrace agriculture have been conducted. This paper reviewsed most available works on the protection of rice terraces in three aspects, which includeing protected objects, existing problems and causes, and protective measures. In tThe protected objects were, mainly the landscapes, ecosystem services and social cultures in rice terrace areas are in three main parts. The protected landscape elements included terrace structures, water conservation forests, farm irrigation systems and villages. The key protected objects in the ecosystems covered traditional crop varieties, biodiversity, environmental quality of terraces and the comprehensive agricultural patterns. The protected social culture mainly consisteds of material cultures (e.g., traditional costumes and old buildings), spiritual cultures (e.g., ethnic songs and dances and traditional festivals), and system cultures (e.g., management of water resources and forests). The challenges facing rice terrace systems contained landscape destruction, environmental pollution, loss of biodiversity and disappearance of traditional cultures. These challenges weare primarily caused by the impacts of modern science and technology, market demands, low comparative advantages of traditional agriculture and unscientific industrial development. As to these challenges, many protective measures need to be implemented. They wereare grouped into three types: reasonable industrial development, building institutions and protective management mechanisms, and developing scientific research, based on searchable and referable protection of rice terraces. In the future, studies on rice terrace conservation should focus on mechanisms of key terrace issues, case studies, comprehensive subject researches, long-term observation studies and industrial development researches.