WD—Wakefield, E. & Dennis, R. W. G. (1950), Common British Fungi, London.

Z—Zeitlmayr, L. (1968), Wild Mushrooms, London.

(iii) Fairy rings

Object: To assess the annual radial growth of fairy-rings and to correlate this with any obvious environmental change.

Materials: Graph and tracing papers, tape-measures, note-book, pencil and rule, small pieces of cane about four inches long and coloured dye (e.g. Eosin solution, Janus Green).

Method: Select a fairy-ring on the school cricket pitch or hockey pitch, school lawn, local golf course or park at a time when the fruit-bodies are first visible. Carefully mark the centre of the ring by driving into the soil a piece of cane until the top is only just visible. Plot this point on graph paper and relate it to any prominent feature nearby, e.g. post, tree or hedge.

Carry out weekly observations throughout the fruiting season plotting the individual fruit-bodies on tracing paper, which is trimmed so as to make a replica of the original graph-sheet. A small dab of coloured dye placed on a fruit-body will assist one in recognising fruit-bodies from previous observations. During the fruiting season observe and plot the zones of differently coloured vegetation—devise some method of describing (and measuring) these colours perhaps by comparison with a colour-chart, printed or hand prepared. Continue observations on the ring at monthly or fortnightly intervals after the disappearance of the fruit-bodies, and record subsequent changes in the vegetation for twelve months.

This project can be continued for several years and for different species of fungus. Weather conditions may be noted simultaneously with the growth observations, or obtained from a reliable source of similar information close by. In this way not only is the increase in ring size measured but the results can be considered in the light of climatic data; fungal growth appears to be dependent on favourable weather conditions.

Further experiments:

  1. Compare the effect that different species of agaric have on the same type of vegetation.
  2. Observe selected fairy-rings for several seasons then either apply fertilisers, particularly calcium-based fertilisers to the ring-area, or mow the vegetation. Note increase in fruit-body production, if any, changes in period of fructification or increase in rate of ring development.
  3. Prepare transects across the fairy-ring and observe the species of flowering plants and mosses present, the differences between species in the two stimulated zones, and the colonisation of the dead zone by annuals and later perennial grasses and herbs.
  4. To the soil from each zone apply simple soil-dilution plate-methods for the culture and isolation of soil fungi and bacteria. Compare the results with those obtained by similar methods from soil without the fairy-ring.