Ecological species groups of upland northern hardwood – hemlock forest ecosystems of the Sylvania Recreation Area, Upper Peninsula, Michigan

Abstract

A tabular, field-oriented method of developing ecological species groups was applied in a classification study of upland northern hardwood – hemlock ecosystems in the Sylvania Recreation Area, Upper Peninsula, Michigan. Sixteen species groups were formed, consisting of a total of 76 upland herb, shrub, and moss species. The groups were constituted based on patterns of presence and absence and coverage values of species along gradients of soil fertility and soil moisture. The ecological responses of species within many of the groups were very similar. The environmental tolerances of the species groups in relation to soil fertility, moisture, forest floor conditions, and shade tolerance were described and contrasted. The groups were more differentiated along a fertility gradient than along a moisture gradient. The tabular method was relatively simple, yet effective in determining the species groups. The method is suitable for extensive land-classification activities; its essential element is that physiography, soil, and vegetation are examined simultaneously in the field. Species groups are more reliable in site classification and mapping than a subset of a few key species and the groups also simplify the use of many indicator species for field workers and ecosystem mappers.