The study of soil chemistry through quasi-steady-state models: 1. Mathematical definition of model

We investigated the communities of filamentous fungi and yeasts in logs in advanced stages of decay.Decay stages are generally defined from class I—V, with class I being the least decayed and class V beingthe most decayed. Fungi were isolated from cross-sections approximately 15 cm thick of Pseudotsugamenziesii logs in decay classes III and IV. Cross sections included portions of logs with and withoutconifer seedlings. Samples were removed from three vertical positions (top, middle, and bottom) ofeach cross-section. Comparisons of coefficient of community and detrended correspondence analysisordinations indicated differences in community structure between class III and class IV logs. Nocommunity differences were found between samples with and without conifer seedlings. A total of 18genera and 36 species of fungi were recovered from samples; more than 50% of recovered genera weredematiaceous hyphomycetes.
Key Words: Ecology, wood decay, fungus communities, Pseudotsuga