(Fig. 12.1). Soils in the Lake Superior and northern Lake
Michigan and Huron drainage basins are in the frigid
soil-temperature class, i.e., the mean annual soil temperature
at 50 cm is between 0 and 8 °C. In contrast, soils in the
southern Lake Michigan and Huron and Lake Erie and
Ontario drainage basins have a mesic soil-temperature class,
i.e., the mean annual soil temperature at 50 cm is between 8
and 15 °C.
The Great Lakes are subject to “lake-effect” snow,
whereby a cold air mass moves across long expanses of
warmer lake water, warms the low layer of air which picks
up water vapor from the lake, rises up through the colder air
above, freezes and is deposited on the leeward (downwind)
shores (see Fig. 2.1). In the Lake Superior drainage basin,
average annual snowfall ranges from 200 cm along Minnesota’s North Shore to over 500 cm on the Keweenaw
Peninsula; in the Lake Michigan basin, snowfall ranges from
100 cm along the south shore to over 375 cm on the
northeast shore; in the Lake Huron basin, snowfall ranges
from 75 cm along the south shore to over 250 cm along the
north shore; on Lake Erie snowfall ranges from 95 cm at
Toledo on the southwest shore to 260 cm at Erie, PA, on the
northeast shore; and on Lake Ontario snowfall ranges from
120 cm at Hamilton, ON, along the southwest shore to
280 cm at Watertown, NY, on the eastern shore.
12.2.3 Vegetation Gradient
A pronounced bioclimatic tension zone separates the temperate mixed broad-leaved and coniferous forest (boreal and
Great Lakes-St. Lawrence Forests) to the north from
broad-leaved forest (Carolinian Forest) to the south
(Fig. 12.1). The tension zone begins at about 50° N and dips
sharply to the south across Minnesota, separates Wisconsin
and the Lower Peninsula of Michigan in half, and continues
across Ontario along the north shore of Lake Ontario. In
Wisconsin the tension zone comprises 13% of the state area
but has 40% of the endemic soils, a large number of which
are bisequal (Bockheim and Schliemann 2014).
The effect of the Great Lakes on the distribution of
Spodosols is of particular interest. In northeastern Minnesota, Spodosols occur only to a limited extent (494 km
2 ),
possibly because of limited snowfall. They occur primarily
as forested Orthods downslope of summits where snow
accumulates (McHugh, unpublished). The separation
between Spodosols and Alfisols in Wisconsin occurs at 45°
00′ N, in Michigan at 43°–44° N, in central Ontario at 44°
30′ N, and in eastern Ontario at 44° 20′ N (Fig. 13.1). The
sharp break between Spodosols and Alfisols across the Great
Lakes has been attributed to (i) the contact between mixed
deciduous and coniferous forest and deciduous forest (Curtis
Table 12.1 Density of soil
series in the US and Canadian
Great Lakes Coastal Zone
Lake
States
Shoreline length (km)
No. soil series
Density (No./km
2
)
US; scale 1:24,000
Erie
MI, OH, NY, PA
1092
143
0.026
Ontario
NY
547
101
0.037
Superior
MI, WI, MN
3186
233
0.015
Michigan
MI, WI, IN, IL
2673
317
0.024
Huron
MI
1853
263
0.028
Total
9351
691
0.015
Canada; scale 1:63,350
Ontario
ON
781
27
0.007
Erie
ON
929
26
0.006
Huron
ON
1879
38
0.004
Total
3589
91
0.005
Table 12.2 Soil series density
in the United States by region
Region
No. units
Average area (km
2
)
Soil series density
Avg.
St dev
CV
Land Resource Region
26
3,32,878
0.005
0.007
140
Major Land Resource Area
25
45,107
0.005
0.004
88
State
50
1,82,949
0.005
0.004
80
Great Lakes coastal zone (US)
5
5750
0.015
0.005
33
142
12 Pedodiversity of the Great Lakes Coastal Zone
Michigan and Huron drainage basins are in the frigid
soil-temperature class, i.e., the mean annual soil temperature
at 50 cm is between 0 and 8 °C. In contrast, soils in the
southern Lake Michigan and Huron and Lake Erie and
Ontario drainage basins have a mesic soil-temperature class,
i.e., the mean annual soil temperature at 50 cm is between 8
and 15 °C.
The Great Lakes are subject to “lake-effect” snow,
whereby a cold air mass moves across long expanses of
warmer lake water, warms the low layer of air which picks
up water vapor from the lake, rises up through the colder air
above, freezes and is deposited on the leeward (downwind)
shores (see Fig. 2.1). In the Lake Superior drainage basin,
average annual snowfall ranges from 200 cm along Minnesota’s North Shore to over 500 cm on the Keweenaw
Peninsula; in the Lake Michigan basin, snowfall ranges from
100 cm along the south shore to over 375 cm on the
northeast shore; in the Lake Huron basin, snowfall ranges
from 75 cm along the south shore to over 250 cm along the
north shore; on Lake Erie snowfall ranges from 95 cm at
Toledo on the southwest shore to 260 cm at Erie, PA, on the
northeast shore; and on Lake Ontario snowfall ranges from
120 cm at Hamilton, ON, along the southwest shore to
280 cm at Watertown, NY, on the eastern shore.
12.2.3 Vegetation Gradient
A pronounced bioclimatic tension zone separates the temperate mixed broad-leaved and coniferous forest (boreal and
Great Lakes-St. Lawrence Forests) to the north from
broad-leaved forest (Carolinian Forest) to the south
(Fig. 12.1). The tension zone begins at about 50° N and dips
sharply to the south across Minnesota, separates Wisconsin
and the Lower Peninsula of Michigan in half, and continues
across Ontario along the north shore of Lake Ontario. In
Wisconsin the tension zone comprises 13% of the state area
but has 40% of the endemic soils, a large number of which
are bisequal (Bockheim and Schliemann 2014).
The effect of the Great Lakes on the distribution of
Spodosols is of particular interest. In northeastern Minnesota, Spodosols occur only to a limited extent (494 km
2 ),
possibly because of limited snowfall. They occur primarily
as forested Orthods downslope of summits where snow
accumulates (McHugh, unpublished). The separation
between Spodosols and Alfisols in Wisconsin occurs at 45°
00′ N, in Michigan at 43°–44° N, in central Ontario at 44°
30′ N, and in eastern Ontario at 44° 20′ N (Fig. 13.1). The
sharp break between Spodosols and Alfisols across the Great
Lakes has been attributed to (i) the contact between mixed
deciduous and coniferous forest and deciduous forest (Curtis
Table 12.1 Density of soil
series in the US and Canadian
Great Lakes Coastal Zone
Lake
States
Shoreline length (km)
No. soil series
Density (No./km
2
)
US; scale 1:24,000
Erie
MI, OH, NY, PA
1092
143
0.026
Ontario
NY
547
101
0.037
Superior
MI, WI, MN
3186
233
0.015
Michigan
MI, WI, IN, IL
2673
317
0.024
Huron
MI
1853
263
0.028
Total
9351
691
0.015
Canada; scale 1:63,350
Ontario
ON
781
27
0.007
Erie
ON
929
26
0.006
Huron
ON
1879
38
0.004
Total
3589
91
0.005
Table 12.2 Soil series density
in the United States by region
Region
No. units
Average area (km
2
)
Soil series density
Avg.
St dev
CV
Land Resource Region
26
3,32,878
0.005
0.007
140
Major Land Resource Area
25
45,107
0.005
0.004
88
State
50
1,82,949
0.005
0.004
80
Great Lakes coastal zone (US)
5
5750
0.015
0.005
33
142
12 Pedodiversity of the Great Lakes Coastal Zone