Analysis of spatial and temporal variation in the community structure of yeasts associated with decayingOpuntia cactus.

The microbial structure within, between, and over time in decaying cladodes of the common prickly pearOpuntia stricta was studied at each of two separate localities. In general, the effective number of yeast species and yeast species diversity increased as the rot aged to the observed maximum time of 4 weeks. Yeast heterogeneity at the two localities differed in the mode of environmental influence, with spatial variability (among rots) most important at one and temporal variability (within rots over time) most important at the other. Differences in cactus density and quality (age) are most likely determinants of the differences in yeast community structure.