Ae. Grondin et Jr. Johansen, MICROBIAL SPATIAL HETEROGENEITY IN MICROBIOTIC CRUSTS IN COLORADO NATIONAL MONUMENT .1. ALGAE, The Great Basin naturalist, 53(1), 1993, pp. 24-30
Spatial heterogeneity in visually similar sites under Utah juniper can
opy in Colorado National Monument was examined. Sample sites were arra
nged in a transect 24 m long, such that distances between samples were
0.013 m, 0.03 m, 1.0 m, 12 m, and 24 m. Twenty-five taxa of algae wer
e observed, mostly belonging to Cyanophyta. Algal density varied by mo
re than order of magnitude within the 46 samples examined. The coeffic
ients of variation for each distance class were very similar, demonstr
ating that algal patchiness can be as significant on a scale less than
0.013 m as it is on a scale of 24 m. Goodall's random pairing analysi
s of spatial pattern supported this conclusion by indicating that the
minimal area for sampling soil algal crust populations at this site wa
s equal to or less than 0.013 m. Because of the microscale heterogenei
ty in algal communities in this study, we recommend that future resear
chers take composite samples if they wish to quantify algae of microbi
otic crusts.