Agriculture Reference
In-Depth Information
140
From 1955
y = -0.75x + 1558 (R
2
= 0.25, P < 0.001)
120
100
80
60
40
From 1924
y = -0.24x + 547 (R
2
= 0.05, P = 0.03)
20
0
1920
1940
1960
1980
2000
Figure 1.7
. Long-term trends in ice duration on Gull Lake at KBS for the periods 1924-2011
and 1955-2011. Ice seasons potentially span two calendar years and therefore the x-axis
depicts the year each winter began. From S.Hamilton (unpublished data).
channels. There are 200 lakes within 50 km of KBS, most of which originated as
ice-block depressions in the outwash plains formed as the glacial ice melted. KBS
is located within the Gull Creek/Gull Lake watershed (97 km
2
) and the Augusta
Creek watershed (98 km
2
), both within the Kalamazoo River basin (5232 km
2
). At
the watershed scale, most water movement occurs through groundwater aquifers,
and water sources to all streams and most lakes and wetlands are dominated by
groundwater inputs (Hamilton 2015, Chapter 11 in this volume).
Soils in the area thus developed on glacial till and outwash following the last
glacial retreat. The predominant soils at and around KBS are Alfisols, developed
under upland forest vegetation. MCSE soils are well-drained Alfisol loams of the
Kalamazoo series (fine-loamy, mixed, mesic Typic Hapludalfs) co-mingled with
well-drained loams of the Oshtemo series (coarse-loamy, mixed, mesic Typic
Hapludalfs) (Mokma and Doolittle 1993, Crum and Collins 1995). Surface soil
sand and clay contents average 43 and 17%, respectively (Robertson et al. 1997),
and dominant silicate minerals include plagioclase, K-feldspar, quartz, and amphi-
bole (Hamilton et al. 2007). Carbonate minerals (dolomite and calcite) are com-
mon in glacial drift and occur at depths below 1 m; they have been leached out of
the upper soil profile at KBS (Kurzman 2006, Hamilton 2015, Chapter 11 in this
volume), as is typical of glacial soils elsewhere in the Great Lakes region (Drees
et al. 2001).
Pre-European settlement vegetation of the area consisted of a mixture of forests,
oak savannas, and prairie grasslands (Gross and Emery 2007, Chapman and Brewer
2008). Southwest Michigan was part of the “prairie peninsula” (Transeau 1935) that
appears to have developed during a prolonged dry period 4000-8000 years ago
along the south and southeastern edge of Lake Michigan. Fires were likely frequent
during this period and, beginning ca. 700 c.e., were actively promoted by local
