I noticed that all the leaves had finally fallen from the huge poplars at the corner of our property.
As Chelsea moved very slowly through them (the vet told me she's the dog equivalent of 90+)
I picked up a random sample and tried to estimate the biomass of Melampsora (a rust fungus) in the dead leaves.
Of course, I'm not being properly scientific about it. To begin with I'm guessing that the trees had 100,000 leaves (at least)
Every leaf I picked up had at least a few black spots of the telial stage of the rust, and most had more than 100,
while some had about 1000 (see photograph). My guess is that the average leaf has about 5% fungal biomass (some much less, some much more). I weighed ten randomly chosen leaves, and was pleased when they weighed in at 10 grams, or 1 gram each, which simplifies the arithmetic tremendously. So - 100,000 grams = 100 kg of leaves 5% of that is 5Kg, or 11 pounds of fungal biomass.
It would take another more difficult process to work out how many basidiospores are likely to be released in Spring, but I know it would be astronomical, so I'll leave that for another day.