RESEARCH ON MYCORRHIZAS - TRENDS IN THE PAST 40 YEARS AS EXPRESSED INTHE MYCOLIT DATABASE

A detailed analysis of MYCOLIT, a comprehensive bibliographic database of mycorrhizal research containing almost 12000 references, showed so me interesting trends over the past 40 yr. During the last four decade s, the average number of papers published per year were 84, 110, 214 a nd 488, respectively. The current rate of publication is about 700 pap ers per year. Much research has focused on nutrient dynamics, inoculum production, mycorrhiza formation, and morphology and physiology of bo th vesicular-arbuscular mycorrhizas (VAM) and ectomycorrhizas (EM). Th ere has been a shift of attention from EM to VAM since 1970. Very litt le work has been done on the other kinds of mycorrhizas. Barriers to p rogress in some areas, such as our inability to grow the Glomales in a xenic culture, have stimulated a large number of methodological papers over the past decade, while the genetics and molecular biology, espec ially of VAM, have been neglected. Ecological studies were more numero us than any other kind. However, there was a bias towards laboratory s tudies as opposed to field studies. Within field studies, researchers focused on agricultural ecosystems, while neglecting disturbed and esp ecially natural systems. This analysis also suggests that we may know less than we think about mycorrhizas, since we have consistently based broad hypotheses and conclusions on studies of a small number of taxa . Future research should be directed towards correcting the various im balances revealed by this analysis.