the winter, soil moisture may not be obvious. In the fall and winter species identification would be more difficult (foliage absence) and conditions would discourage lengthy note-taking. Even the most comprehensive notes on forest cover represent transects through townships, for the establishment of lot corners, not for the purpose of providing comprehensive forest cover data. The forest cover analysis and interpretation for any physiographic type is constrained to areas where adequate data are available.
2.2.2.2 Upland Forest Tree species frequency Table 1 shows the frequencies of tree species in upland forest (forest not noted as wetland or lowland in surveyors' notes) varied with physiography. Using this table, a map of historical forest cover was prepared (Figure 3). The species richness of these forests ranged from nine (till plain) to 19 species (clay plain). Seven species occurred in all five physiographic types (sugar maple, beech, elm, basswood, hemlock, cedar, ash). Sugar maple was most frequently recorded on limestone plains and till plains. Beech was found most often on till plains, followed by limestone plains. Elm was most common on limestone plains where it occurred on 60% of the lots. Basswood was most frequent on clay and till plains. Hemlock was found in close to half the lots examined in all regions except clay plains. Cedar and ash occurred in less than 15% of the lots in all physiographic types. In the lots examined, white pine was not recorded from the limestone plain. Oak and white oak as well as red pine and red spruce were recorded infrequently and only on clay plains. Poplar and soft maple were noted only on sand and clay plains. Till and rock, sand plains and clay plains supported birch and balsam fir. Table 2 shows that sugar maple was the dominant species on limestone plains and a co-primary species on sand plains (with hemlock) and clay plains (with white pine). Hemlock dominated till and rock. On till plains, beech (almost as frequently mentioned as sugar maple, Table 1), was more often listed first. Table 3 shows the frequency of species occurring second in surveyors' species lists. Considering the three most frequent species for each physiographic type, sugar maple is again an important secondary component of forest cover. On all types except till and rock, elm frequently occurs as secondary species. Beech is the most common secondary species on sand plains and important on limestone and till plains. Spruce is a secondary component on sand and clay plains. White pine was observed as a major secondary component only on till and rock.
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