A Comparison of the Soil Fungi of a Tall-Grass Prairie and of an Abandoned Field in Central Oklahoma

Abstract

1. The soil fungi of two grassland plots in central Oklahoma were compared during 1952. Species numbers were determined for each of 9 months in an abandoned field and a prairie. 2. The average number of fungi per gram (based on the total number of colonies per plate) was greater in the field plot throughout the year. The difference in numbers between plots was greatest in early summer and winter and least in spring and late summer. Numbers in both plots were lowest in summer and highest in spring. 3. Usually a greater number of species was found in the abandoned field. The average percentage of species common to both plots was 35.2. A greater number of species was found in the abandoned field only (average 37.4%) than in the prairie only (average 27.9%). 4. Although a few species appeared with a high frequency throughout the year, most species were of seasonal or sporadic occurrence. This means that the species composition of each plot changes from season to season and, to a lesser degree, from month to month. Some definite differences were found between the fungous populations of the two plots on a monthly or seasonal basis. These differences included variations in the principle species of the two plots and the presence of species which occurred in high numbers in only one of the plots. 5. Individuals of a species did not have a Poisson (random) distribution.