Geographical distribution of fungi

Abstract

During a sojourn of some years in Manitoba, I became impressed by the large number of genera and species of fungi there in an environment that I had supposed would be unfavorable for them. Diligent collecting, by a few others and myself, disclosed 2,625 kinds, including 98 myxomycetes. It seemed evident that more than 5,000 species must be present (6), though only some 1,200 phanerogams are known to grow there without cultivation, and a hundred of these are introduced weeds or escapes. Green plants, then these fungi, had arrived and established themselves during not more than 25,000 years since the last glacier retreated. After some thought and analysis I concluded (5) that at least twice as many phanerogams as fungi had been described for the world, but that in any state or country the number of species of fungi is likely to exceed the number of species of phanerogams because of the greater average range of a fungus; that the smaller the area surveyed, the greater is the excess of fungi; that saprophytic fungi generally have wider distribution than parasitic; and that distribution of hosts and substrata, principally flowering plants or their remains, has more influence than climate upon distribution of fungi. Those conclusions are fairly obvious, but it should be possible to extend them. I now realize that a number of Manitoban fungi were not good morphologic species; that I had given most of my attention to the fungi of temperate regions, and therefore underestimated the effect of climate. The study of distribution may be approached from various angles, from that of the whole world and all time to that of today's dispersal over one acre. I happened to be present during the arrival of a few fungi in Manitoba (5, 8); those recognised as new were all parasites of cultivated plants; I knew of no sure means of ascertaining when other fungi had reached the Province.