Welcome to Colorado Mesa University · 2020. 11. 2. · 1.0 c 0.5 0.0 2000 ZUSGS science for a...
Transcript of Welcome to Colorado Mesa University · 2020. 11. 2. · 1.0 c 0.5 0.0 2000 ZUSGS science for a...
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Surface disturbances destroy biocrusts and
they take a LONG time to grow back
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The replacement of in-tact biocrusts with bare ground
or early successional biocrusts influences local and regional hydrology
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~1860
~1000 BC
~3000 BC
~1920
~1000 BC
~1850
~1920
Pacific Railway Act - 1862
Taylor Grazing Act - 1934
Neff, J. C., et al. "Increasing eolian dust deposition in the western United States linked to human activity." Nature Geoscience 1.3 (2008): 189
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Porphyry Basin tarn sediments
5-7x increase in deposition of K, Mg, and Ca (peaking in early 1900s)
5-10x increase in N and P, mostly since ~1950, (not peaked)
Lakes in the San Juan Mountains, Colorado
Al
Ca
K
PN
(Neff et al. 2008 Nature)
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Dust
Clean
Nat
ural
ized
Run
off
(BC
M/d
ay)
Mexico’s annual allotment
LV
LA
* Based on pre-2009 dust loading
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