Observational data on vegetational communities and water levels, plus pH measurements show that the small-scale distribution of Andromeda glaucophylla and Kalmia polifolia results from chemical and moisture gradients within a given bog. Zonation occurs on the microhabitat scale of hummock and hollow and on the larger scale of surrounding forest to bog mat to lake edge. As Crum (1988) observed, even on a hummock-scale, zonations of bryophytes and bryophyte succession create habitats of differing suitability for Kalmia and Andromeda. The effects of vegetation on the pysical environments makes a sort of bog-within-a-bog effect: small areas take on their own unique chemical and hydrological properties, so influencing the communities of flora which can colonize and thrive on that spot.http://deepblue.lib.umich.edu/bitstream/2027.42/54496/1/2934.pdfDescription of 2934.pdf : Access restricted to on-site users at the U-M Biological Station
