Bacteria 



Microflora Activities and Decomposition 297 



Fungi 



Percent Active on Each Substrate 



FIGURE 9-1. Percentages of fungi and bacteria capable of ex- 

 ploiting specific organic substrates. Bacterial percentages are 

 based on 200 randomly selected, aerobic types isolated from 

 the 0- to 2-cm soil depth in wet meadows and tested at I5°C. 

 Fungal percentages are based on percent frequency of major 

 species and their ability to utilize specific substrates as sole car- 

 bon sources in vitro. (Benoit and Flanagan, unpubl.) 



Fungi 



The major taxonomic groups of phyllosphere, litter and soil fungi 

 have been discussed (Chapter 8). The ability of these groups to utilize 

 pectin, starch, cellulose and lignin has been tested (Flanagan and Scar- 

 borough 1974). Comparison among the mycoflorae of the phyllosphere, 

 Htter and soil reveals different enzyme potentials for substrate degrada- 

 tion as integrated over the season (Figure 9-1). Generally, the mycoflorae 

 of litter and soil are better able to degrade the more recalcitrant sub- 

 strates than is the mycoflora of the phyllosphere. Fungi in standing dead 

 leaves are infrequently cellulolytic (10%), while in litter and soil 27% and 

 35% respectively are cellulolytic. The pattern is repeated for polyphenol 

 oxidizers, some of which (gallic acid oxidizers) are better represented in 

 litter and soil than are cellulolytic forms. The potential to utilize humic 

 acids also is represented better among litter and soil fungi than among 

 fungi of the phyllosphere. Fungi decomposing pectin and starch make up 

 the greatest portion of the mycoflora, whether from phyllosphere, litter 



