Thursday, January 3, 2013

Numbers of Fungi

The part of my brain that deals with numbers is quite well-developed (in contrast, some would say, with other more important areas).  (Though some physicists suggest that the Universe is actually made up entirely of numbers). However, I am grateful that it didn't decide to turn me into an accountant.  At least I get to play with numbers of my own choice.  I also decided, a long time ago, to play with fungi.  So today’s blog melds the two. 

Numbers of Fungi

How many fungi exist on Earth?  We don’t know, since we have so far described only about 100,000.  That may sound like a fairly big number, and it does represent a lot of work, as I can attest from having been involved in describing about 300 of them for the first time.
However, a comparison of the numbers of plants and fungi in the British Isles suggests that there are about six times as many fungi as plants.  Since there are about 250,000 plants in the world (they are big enough to see and we have searched for them pretty thoroughly) there should be about 1.5 million fungi.  We were more or less happy with that estimate, despite the mountain of work that lay before us in describing them all.  Then rapid means of sequencing loose DNA lying about in the environment came along.  Now if we sequence what is in, for example, a rain or soil sample, we will obtain about 20 times as many kinds of fungal DNA as there are culturable specimens  This changes the arithmetic, suggesting that there may actually be as many as 30 million fungi, most of them unculturable, so for all effects invisible.
Well, that’s fungal astronomy.  Now for some more down-to-Earth studies.  A few of us have been listing fungi found in a forested mountain park (John Dean Provincial Park) just behind where I live.  We have so far found just over 300 mushrooms and other fungi, including the one shown below, which is a colourful species of Nectria.  We brought a sample home and I photographed it through my dissecting microscope with my Galaxy Android phone (Now, there’s a relatively new phenomenon for you).

If you look carefully, you should be able to see the little apical point on each perithecial ascoma, which is where the ascospores are shot out.

Another less local study was 5-year attempt to produce a catalogue of the fungi of Haida Gwaii (formerly known as the Queen Charlotte Islands), an archipelago of the west coast of Canada.  This study produced a list of 615 species.  This number was limited by weather and funds, which permitted access to the Islands only in certain months of the year, and limited our over-all number of collecting trips.

Nevertheless, the study showed clearly some differences between the mycota of the Islands and the Mainland.  These differences may have been accentuated by the fact that such trees as the Arbutus, true firs and Douglas fir don’t grow there.

Now, moving close to home again, two distinguished local Botanists, Oluna and Adolf Ceska, who happen to be a couple, have been collecting fungi on another nearby forested hill called Observatory Hill just north of Victoria.  They have so far, over seven years, and about 200 visits, compiled just over 1100 species, including some rare and undescribed taxa. 

Next time I will discuss the periodicity of fungal fruiting, as revealed in these and other studies.