Ecological Significance of Four Critical Elements in Plants of Raised Spagnum Peat Bogs

The concentrations of N, P, Mn, and Al in plants of two ombrotrophic bogs and four adjacent environments were examined. The current year's foliage of the evergreen bog species, as contrasted with the older leaves, invariably possessed higher concentrations of N and P and lower concentrations of Al and Mn. Within the bog species, the composition of the current year's foilage of the evergreens was not significantly different for any of the elements from that of the deciduous species. Foliage of the bog species was lower in content of N and P than the foliage of plants of other habitats and reflects the paucity of available N and P in the bog substrate. Broad—leaved evergreen leaves of bog plants appear to manufacture more photosynthate per acquired unit of N or P than do deciduous leaves, primarily because of their longevity. The high occurrence of evergreenness in infertile environments may therefore reflect a decreased need to acquire N and P from a substrate deficient in these elements. Mn and Al contents were comparable in the bog plants to plants of other habitats, despite potentially toxic levels of these elements in acid bogs. Apparently many bogs plants selectively exclude Mn and Al.