Analysis of development trend of karst carbon cycle and carbon sink effect based on Web of Science
Karstification refers to the chemical dissolution of carbonate rocks by water and the deposition of calcium carbonate due to CO2 degassing.In a macro sense,karstification can be divided into epikarstification and deep-seated(geothermal)karstification.Karst covers about 22 million km2 all over the world,accounting for 15%of the land area,and is of enormous carbon sink potential.Therefore,to alleviate the pressure of carbon neutrality and help China achieve the"Dual Carbon"target,it is of great significance for us to accurately understand the relationship between karst and carbon cycle and the carbon sink effect of karst.As an important tool for us to comprehensively understand the research progress in a specific area,bibliometric analysis can measure the relationship and influence among publications through a series of mathematical and statistical tools,and hence has been applied in many research fields.In order to understand the research hotspots and the development directions in the field of karst carbon cycle and carbon sink effect,this study undertook bibliometric citation analysis on 573 contributions to the literature written from January the 1st,1991 to June the 6th,2017,based on the Web of Science core collection.CiteSpace was used to analyze keyword frequency and emergency,country(region)and institution,author impact,research hot spot,co-cited literature and evolution of research topics.In terms of the number of papers published every year,there were fewer papers published before 2007,with a slow increase from 2007 to 2014 and a significant increase after 2015.The analysis of papers published by national(region)found that the research on karst carbon cycle and carbon sink effect presented distinct regional characteristics,which was mainly led by China,followed by the United States,Europe and other regions.Cluster analysis on the top 100 keywords in 573 papers by CiteSpace software generated 11 clusters which could be summarized and integrated into 5 main clusters:1)the carbon cycle and carbon sink of chemical weathering of carbonate rocks;2)the carbon cycle and hydrochemical characteristics in karst water;3)the soil carbon cycle and carbon sink in karst regions;4)the impact of ecosystem services on karst carbon cycle and carbon sink;5)the technology of stabilizing carbon isotopes.The analysis of authors and cited references found that the research team led by Liu Zaihua has inherited and developed the viewpoint put forward by Yuan Daoxian that karstification participates in the global carbon cycle and has a carbon sink effect.Besides,Liu Zaihua team proposed a coupled carbonate weathering model,which greatly promoted the research of karst carbon sink.The analysis of references with the strongest citation bursts shows that citations about coupled carbonate weathering model,impact of karst rocky desertification,climate change and change of land use,effects of sulfuric acid as well as ecological engineering on karst carbon sink have attracted widespread attention in a short term and can represent cutting-edge research hot spots.The time line map and the keyword time zone map of keyword clustering can clearly show the research development in the field of karst carbon cycle and carbon sink in three stages:1)the initial stage from 1997 to 2006,in which relevant studies show that the global amount of atmospheric CO2 uptake from weathering of carbonate rocks was estimated at 0.11-0.608 Gt C·a-1,accounting for 15%-30%of global carbon leakage;2)the stage of rapid development in research on the chemical weathering of carbonate rocks from 2007 to 2014,in which studies mainly focused on the impact of exogenous acids,runoff conditions,and vegetation cover on the weathering of carbonate rocks in different watersheds;3)the new stage of research on carbon cycle and carbon sink after 2015,in which studies have been conducted under the guidance of karst critical zone theory based on the atmosphere-biology-soil-water-bedrock system,and they mainly focus on the effect of aquatic photosynthesis,considering the impact of climate change and land-use change.In the future,the research of carbon cycle and carbon sink in karst critical zones should be carried out under the guidance of earth system science theory.At a micro level,studies should focus on the catalysis of carbonic anhydrase in soil,microbial carbon sequestration,photosynthesis of aquatic plants and other biological carbon pumps to improve the potential of karst carbon sink.At a macro level,studies should pay attention to the impact factors such as climate change,change of land use,and change of ecosystem service functions under human activities.
万方数据
维普
