Some Observations on the Protozoa of Some Beechwood Soils on the Chiltern Hills

Abstract

The distinction between two biologically distinct kinds of humus, namely mull and mor, was made by P. E. Muller whose conclusions were partly derived from his study of Danish beechwoods (Handley 1954). Muller observed that earthworms and moles were absent from the mor soil but were present in the mull. Bornebusch (1930) made a more detailed study of the fauna of the different soil types confirming the distinctions made by Muller and showing that although there were more animals in mor they were of less total weight than the animal population of the mull soils. A detailed study of the animal community of a beech mor was made by van der Drift (1951), who also reviewed the literature. Less is known of the microfauna. Overgaard Nielsen (1949) has examined the nematode populations of mull and mor and Varga (1935) and Volz (1951) have examined the protozoan fauna of beechwood soils. However, there does not appear to have been any previous attempt to compare the protozoan fauna of beech mull and beech mor. There is little quantitative data on the organic cycle in European beechwoods. Ebermayer (1876, 1890) measured the leaf fall, or rate of accumulation, Harley (1940) measured the weight of leaves and resting winter buds, or the rate of growth, and Brown (1953) gives the height of the trees grown on different soils. Because of this paucity of quantitative data an attempt was made to assess the relative rate of decomposition in mull and mor by respiratory measurements using a Barcroft respirometer. Only a limited number of samples could be examined in the time available. Consequently the results are reported with only a brief discussion.