I. Objectives: The following experiments-demonstrations are the consequence of my having selected what seemed to me to be three "Great Ideas" ln fungal ecology. They are meant to illustrate, through an inductive process, major concepts about fungal communities and the importance of fungi in ecosystems.

II. Materials:

• About 24 small aluminum loaf pans (2 per week for 12 weeks)
• Aluminum foil
• Litter (uniform mixture of any sort of litter, e.g. hay or leaves from a forest floor)
• Mettler balance
• Dissecting and high power microscopes
• Muffle furnace for ashing--optional

III. Procedure:

1. Let the students figure objective and procedure. Objective may be to something like: 1) determination of progressive dry weight loss in litter kept at uniform temperature and moisture content, and 2) weekly tabulation of the kinds and relative quantities of decomposer-consumer organisms present.
2. Holes for aeration should be punched in both the top and bottom of each compost heap container. Weights which must be recorded at start of the experiment are A) container and b) container + oven-dried hay (use a standard hay weight). Start the experiment by moistening each heap with distilled water to estimated water holding capacity (use a standard amount of water).
3. Each week 2 of the heaps will be sacrificed and 3 weights obtained. Comparison of moisture content water and holding capacity water ("soaking wet" weight minus fresh weight) will indicate how much water should be replenished to each of the remaining heaps. Oven-dry weights (dry at 50-55°C for 24 hours) will be recorded each week and later graphed.
4. Decomposer-consumer organisms should be studied, tabulated, and assessed each 2 or 3 weeks. Examine the litter (before trying) using dissecting microscope and higher power microscope magnifications.

IV. Conclusion (general concept you hope the students will come away with): Fungi have an important role in Nature as scavengers. They attack and reduce to humus probably a considerable portion of the organic matter elaborated each year by the producers (green plants) in ecosystems. Elimination/alteration of the fungal community in litter surely would affect the intricate sequence of biotic interactions involved in degradation of organic debris.

V. References:

Burges, A. and F. Raw (ed.). 1967. Soil Biology. Academic Press.

Burges, Alan. 1958. Micro-organisms in the Soil. Hutchinson & Company, Ltd.

Clark, F.E. and E.A. Paul. 1970. The microflora of grassland. Advan. Agronomy 22: 375-435.

Clark, F.E. 1970. Decomposition of organic materials ln grassland soil. U.S. IBP Grassland Biome, Technical report No. 61.

Duddington, C.L. 1957. The Friendly Fungi. Faber and Faber, Ltd.

Gray, T.R.G. and S.T. Williams. 1971. Soil Micro-organisms. Hafner Publishing Company, Inc.

Gray, W.D. 1959. The Relation of Fungi to Human Affairs. Henry Holt and Company, Inc.

Griffin, D.M. 1972. Ecology of Soil Fungi. Syracuse University Press. British Ecological Society).

Odum, E.P. 1971. Fundamentals of Ecology. Third Edition. W.B.Saunders Company.

Whittaker, R.H. 1970. Communities and Ecosystems. The Macmillan Company.