Fig 1.
Decadal evolution of the percentage of publications (“articles” and “reviews”) per branch of knowledge in multidisciplinary journals (according to the Web of Science) from 1980 to 2021.
Fig 2.
a) Position of each research area in the ranking of the number of publications in multidisciplinary journals per year. Number one in the y axis represents the research area with more publications. Graph a) represents the complete graph including all the research areas and the graph c) is the enlarged part indicated by the square (with the axes inverted). b) Number of publications of each research area in multidisciplinary journals per year. Only the first 30 research areas for each graph are shown, decreasingly sorted by the median. Research areas are classified by branches of knowledge and points are colored according to year.
Fig 3.
Relation between the percentage of publications of each research area in multidisciplinary journals and the percentage of publications of that research area in the world.
Graph b) is a zoom of the indicated part of graph a). Each research area is represented by a color. The black line represents the 1:1 ratio, namely the publications in each research area in multidisciplinary journals are proportional to the global publications in that area. Note the great overrepresentation of " Biochemistry & Molecular Biology " in multidisciplinary journals. c) Ratio between the percentage of publications in each research area each year in multidisciplinary journals and the percentage of publications of each research area each year in the world (multidisciplinary:world ratio).
Fig 4.
Yearly multidisciplinarity degree in multidisciplinary journals and correlations.
In graph a), only the first 30 Q1 and Q2 multidisciplinary journals are shown, decreasingly sorted by the median. The journals in bold are top multidisciplinary journals and points are colored according to year. In graph b), all multidisciplinary journals are represented, decreasingly sorted by the median. Black bars represent Q1 and Q2 journals and grey bars represent Q3 and Q4 journals. Top multidisciplinary journals (Nature, Science, and PNAS) are represented by red bars. c) Relation between the percentage of publications in the area “Biochemistry & Molecular Biology” in each multidisciplinary journal and the journals’ impact factor. d) Relation between the multidisciplinarity degree of multidisciplinary journals and the journals’ impact factor. e) Relation between the multidisciplinarity degree of multidisciplinary journals and the percentage of publications in the area “Biochemistry & Molecular Biology” in each multidisciplinary journal. The red lines represent the linear trend lines.