The Microflora 



285 



biomass are positive and the mean growth rate is more rapid. Mean 

 growth rates were also rapid when the 10-day mean temperatures were 

 less than 4°C. This temperature range includes the early part of the grow- 

 ing season when fungal densities increase rapidly (Figure 8-7). When or- 

 ganic and inorganic substrates are readily available, rates of fungal 

 growth may be high despite low temperatures. 



Within different microtopographic units, relative growth rates are 

 normally distributed with a mean of near zero (-0.024) and a variance 

 of 0.13. The distributions are most different between polygon troughs 

 and rims of low-centered polygons, but cannot be distinguished statistic- 

 ally using the Smirnov test. Although temperature regimes differ be- 

 tween troughs and rims the difference is not sufficient to generate differ- 

 ent patterns of fungal growth, and the relationship between temperature 

 and fungal growth rates appears similar in all microtopographic units. 



Under natural conditions temperature appears limiting to fungal 

 growth in aboveground substrates only early and late in the season. In 

 1972 and 1973 growth appeared to respond rapidly to early-season in- 

 creases in the temperature (Figure 8-13). Despite continued warming. 



2000 



FIGURE S-13. Seasonal courses of fungal density and mois- 

 ture content in Eriophorum litter from a wet meadow, 1972 

 and 1973. (Flanagan, unpublj 



