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Figure 16-24. Satellite image of the western Nebraska Sand Hills, United States (see Color Plate 16-24). The eastern
side of this scene displays massive transverse dunes, and smaller barchan dunes are found to the west. The most
active vegetation appears dark green; less active vegetation is pale green. Numerous lakes (blue to black) occupy
the troughs and swales between dunes. Landsat TM bands 2, 5 and 7 color coded as blue, green and red; image
date 10 August 2010. Image from NASA; processing by J.S. Aber.
A
B
Figure 16-25. Predominant land use in the Nebraska Sand Hills. A. Cattle grazing in a wet meadow. B. Harvesting
hay from a wet meadow. Photos by J.S. Aber.
with extensive marshes and wet meadows that
follow elongated swales between large trans-
verse dunes (Fig. 16-26).
The westernmost portion of the Nebraska
Sand Hills consists of lower barchan-style dunes
with lakes of irregular size and shape. These
lakes are hyperalkaline; in some cases, alkalin-
ity exceeds 90,000 mg/L, among the highest
alkalinity values ever measured in natural lakes
(Bleed and Ginsberg 1990). Such high salinity
restricts most wetland vegetation and wildlife,
but does support brine shrimp, brine l ies, and
rotifers. These invertebrates attract large l ocks
of avocets and phalaropes during their fall
migrations. In more alkaline lakes, some inver-
tebrates display bright red and orange colors
(see Color Plate 4-6). This presumably is a
result of carotenoid pigments that may protect
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