Research Status and Future Trends of Litter Soil and Water Conservation Effect Based on CiteSpace Software

In the face of a series of global ecological and environmental problems, how to correctly understand and utilize the soil and water conservation function of forest vegetation has become an important topic, and the soil and water conservation effect of litter has attracted wide attention from scholars and research institutions all over the world. Based on the core complete database of Web of Science and CNKI database, GiteSpace software was used to analyze the international and domestic research literature on litter soil and water conservation effect, aiming to clarify the research overview, analyze the discipline and knowledge structure, and explore the research hotspots, frontiers and trends. The research findings are as follows: (1) From 2000 to 2020, the number of research papers about litter soil and water conservation effect showed a steady growth trend. In recent ten years, the number of papers published reached 1546, accounting for 66.7% of the total number of papers published. The United States led the world in the field of litter soil and water conservation effect research, with the highest number of publications and the intermediary centrality of international cooperation, while China ranked the second in the number of publications, but the international cooperation and influence were weak. (2) In the early stage of development, the knowledge base of litter soil and water conservation effect mainly involved the "carbon 13 nuclear magnetic resonance (NMR)", "model corresponding analysis", "micro perspective", "biological diversity", "Mediterranean forest", and so on, which had formed influential achievements in "pH" clustering. In the second stage of development, it mainly focused on "ecological stoichiometric" clustering, and formed Cornwell's paper on the decisive factors of litter decomposition rate in the world, which became a landmark in the field of research. (3) The research process of litter soil and water conservation effect was roughly divided into three stages, such as starting, developing, comprehensively improving. From 2017, the global climate problems caused by land use and vegetation degradation had become the latest research frontier, and the strong emergent effect continued, which should be the main research trend and direction in the future. (4) The domestic research on the effects of soil and water conservation of litter has not formed a relatively prominent focus and obvious development trend, and the research contents mainly focused on relative basic research levels such as "water holding capacity", "canopy interception", "plantation".