Evaluation of hyphal lengths and fungal biomass in soil by a membrane filter technique.

A membrane filter technique for determination of total hyphal lengths in soil is described. For mycelium from a shake culture of Trichoderma viride, good correlation was found between the hyphal length per gram dry weight as determined by this technique, and the calculated value, based on microscopic measurement of hyphal diameter, dry matter content and density of mycelium. A statistical treatment of the data was obtained by measuring each hyphal fragment and separating them in length classes. Both the total number of fragments within a given area and the number within a given length class follow a Poisson distribution. An Appendix gives a mathematical treatment of the fragmentation process and shows that, theoretically, the accuracy of measurement increases with increasing degree of fragmentation. [ABSTRACT FROM AUTHOR]