Research hotspot and trend of plant water use in karst: Based on a bibliometric analysis from 1984 to 2022

Research on the ecohydrological processes of terrestrial plants is a frontier field comprising ecology,hydrology and global change research, yielding the key theoretical foundations of ecohydrology. In karst areas, due to its unique geological background, the karst landscape is strongly developed, with high bedrock exposure, high permeability, fragmented soils, shallow soils, and high spatial heterogeneity,resulting in very limited water storage for plant uptake and growth in rock fissures and shallow soils.Therefore, water conditions are an important ecological factor influencing plant growth. To comprehensively understand the current progress and development trends in plant water use research focusing on karst areas, this paper uses the VOSviewer software to analyze the literature on plant water use in karst areas between 1984 and 2022. The results showed that:（1） Research on plant water use in karst areas has developed rapidly worldwide, and the number of relevant studies in the literature have increased year by year, which together means that it is attracting more and more attention.（2） The investigation of plant water sources, geological background of karst areas, seasonal arid tropical climates,the relationship between δ13C values and plant water use efficiency, karst plant water use in karst savannas and subtropical areas, and ecosystems under climate change yields the knowledge base in this field.（3） Most studies in this area focus on the division of water sources of plants in karst areas, the methods of studying the water use sources of plants, and the water use strategies and efficiency of plants.（4） Future research will focus on how plant water use in karst areas is influenced by Earth's critical zones, climate change, and ecohydrological separation. These studies will provide a key scientific basis for guiding ecological restoration and promoting sustainable development in karst areas.