is locally dominant on Oak, Otter, Outer, and 
Sand Islands. Balsam-fir dominant forest makes 
up about 7% of the Apostle Islands. It is 
common on the north half of Devils, North 
Twin, and Sand Island. Red maple forest, 
although it makes up about 8% of the Apostle 
Islands, is not as widely distributed throughout 
the Islands, since it is the dominant forest 
primarily on the central part of Stockton Island 
which takes almost one-fourth of the Islands’ 
whole area. 
Hemlock, red oak, and quaking aspen are minor 
forests. Although large hemlock patches occur, 
especially across the northern half of Outer 
Island (Figure 3), forests in which hemlock is 
the first dominant species are few. Hemlock 
comprises 13% of forest stands, but is actually 
the leading dominant in only about 2% of the 
whole area. It often occurs in the form of small 
patches, and is a dominant forest locally on 
Bear, Oak, Outer, and Stockton Islands (Larson 
1975; Judziewicz and Koch 1992). Red oak 
forest is locally dominant only on Oak and 
Basswood Island, comprising about 3% of the 
whole area. Quaking aspen dominant forest is 
very limited. It only makes up about 2% of the 
total area. Most of these forests are found on 
Stockton and Basswood Islands (Anderson et al. 
1979; Stadnyk ef al. 1974; Judziewicz and Koch 
1992). 
White pine and red pine forests are uncommon. 
Most of them are in small patches, mainly 
scattered on sandscapes or along the coast. 
White pine and red pine forests are found as 
large patch dominants on the west side of the 
Presque Isle Point tombolo, at Stockton Island, 
and the south tip of Outer Island, as well as a 
linear patch along the coast near the large bog at 
the Mainland Unit. They make up less then 
0.5% of the whole area. For the white pine forest 
on Devils Island, white pine is not the first 
dominant species. 
Species Frequencies Analysis 
The sixteen most common tree species in terms 
of frequency level were selected from all the 
forest species recorded in FLORADB. 
Frequency level was calculated based on the 
number of occurrences of individuals of each 
species surveyed and recorded by Judziewicz 
64 
and Koch (1992). Species which are not 
discussed herein have lower frequencies and are 
less common. Statistics showing major tree 
species frequency levels are summarized for 
only the islands with the survey plots ( Eagle, 
Gull, and Long Islands are not included). It is 
important to note that a high frequency level of 
a species does not necessarily indicate that it is a 
dominant forest species, due to the complexity of 
species distribution patterns, variation in basal 
areas, and relatively wide range of diameter at 
breast height (dbh). A species frequency level 
only indicates the commonness of the species. 
Figure 4 shows the stem counts of the major 
forest species occurring at 1424 plots recorded 
in FLORADB. The base portion of each column 
represents adult tree frequency level and the 
upper portion represent the summarization of 
seedlings and saplings. Paper birch, yellow 
birch, and balsam-fir are the commonest species. 
They occur in more than 40% of the plots. 
Although it is the commonest, balsam-fir is not 
always the dominant species when it occurs. 
Instead, it is an associated species in many forest 
types. Sugar maple, white cedar, and red maple 
are other common forest species. They occur in 
about 30% of the plots. Sugar maple shows a 
very strong indication of becoming the 
commonest species in the next generation if the 
forest continues to grow without major 
disturbance. 
Sugar maple, paper birch, white cedar, and 
yellow birch are very often dominant forest 
species; red maple is not typically dominant. 
Hemlock, red oak, quaking aspen, and mountain 
ash are minor species. They occur in about 10% 
of the plots. Figure 3 indicates that most of the 
hemlock are on Stockton, Oak, Basswood, Bear, 
and north half of Outer Island. This distribution 
also implies the west-east change within the 
Lakeshore with hemlock being more abundant 
in the eastern islands and fairly rare in the 
western islands, even though logging and fires 
had strong impacts on top of this (J. Van 
Stappen 1994, personal communication). Red 
oak and quaking aspen are locally dominant 
species especially on Oak, Basswood, and 
Stockton Islands. Unlike other species, 
mountain ash is not a dominant forest species in 
most of the cases, although it has fairly high 
frequency levels in some islands. Like balsam- 
fir, it 
many 
White 
tooth 
domir 
Most : 
stand: 
along 
patch 
Island 
Bassw 
comm 
big-to 
Hemk 
domin 
stage i 
comm 
both h 
freque 
to bec 
future 
seedlii 
paper