Jm. Halley et al., PREDICTING STRAW DECOMPOSITION BY A 4-SPECIES FUNGAL COMMUNITY - A CELLULAR-AUTOMATON MODEL, Journal of Applied Ecology, 33(3), 1996, pp. 493-507
1. We have developed a cellular automaton model based on the measured
and inferred properties of the fungal saprophytes, Mucor hiemalis, Agr
ocybe gibberosa, Chaetomium globosum and Sphaerobolus stellatus. In th
is model, the fungal mycelia are represented by the players MH, AG, CG
and SS, respectively. The model was used to investigate the rate of b
reakdown of litter, assumed to be made up of sugar and cellulose, and
the associated persistence of the four model mycelia. We examined the
persistence times of the fungi and the degree of breakdown of the reso
urces. 2. This model reproduces most of the results of competition exp
eriments on malt extract agar medium between different fungi. However,
perfect reproduction of observations was not possible since real fung
i showed a variety of responses under similar conditions. 3. The model
predicts a number of phenomena seen in other experimental situations,
The model expects coexistence between species to continue for longer
when spatial effects are important. Persistence of each species is fou
nd to be greatest for some intermediate level of resource patchiness.
4. The model also exhibits the phenomenon of secondary colonization, o
bligate sugar users can re-colonize through the release of sugars from
the breakdown of cellulose by other fungi. 5. The model predicts that
, when the resources are patchy, decomposition will take much longer t
o complete, If the resources are sufficiently patchy, all species die
before breakdown of resources is complete.