Hydro-climate effects on rangeland ecosystem soils
in the Great Basin: thresholds and transformations
Matt Germino
US Geological Survey, Boise
Forest and Rangeland Ecosystem Science Center
Colleagues: Nancy Glenn, Joel Sankey, Sondra Miller, Many Others
Funding: BLM, DOD
Bigger picture of surface conditions as they relate
to management of Great Basin landscapes
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Species of concern – sagebrush habitats and dependent species
Fire, post-fire restoration is a major conservation investment
Wind energy development, grazing, invasives
Rapid Ecological Assessments – soils are a conservation element
The soil surface: a critical zone for climate effects on
rangeland ecosystems, from a wide range of
perspectives
• Bare soil exposure, relates to sensitivity to disturbance
Fire, grazing effects
• Annuals vs. perennials; seeding/planting
Seeds, germination are key
• Fertility is near surface
• Biological crusts
• Erosion
• Uncoupled from typical
weather station parameters
This talk will focus on fire effects – megafires are a key concern
Wind erosion after fire:
photo by Charley Finley
•Dust storm in 2006 at Clover Fire in S Idaho on an otherwise clear day,
•Reminiscent of dust bowl of 1930’s
•Environmental, health, logistics, liability problems – unambiguous risks.
•Great Basin is a significant source of global dust (Goudie & Middleton 2006)
•Emphasis on wind erosion has been on cropfields, dunes, hot deserts.
• Since mid-1900’s, seeding practices have been common in semiarid
rangelands of Western N America.
•Seeding in emergency post-fire rehabilitation plans is aimed at soil
stabilization and pre-emption of native species.
•Success has been mixed, weather is a major issue.
Photo from USFS RMRS,
Native Plant Increase Project
2003 report from US General Accounting Office notes the large
cost and asks about efficiency of post-fire reseeding
Jefferson Fire, 100K acres, July 16-20, 2010
-Started sampling July 21, 2010
-Replication: 3 full BSNE towers, sensit, and energy/water balance.
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From ARS WERU
Germino et al. Ecological Biogeomorphology, ESA 2012
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22
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p1
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20
Oc
t1
18 0
No
v1
0
26
Ap
r1
1
23
M
ay
11
3A
ug
11
10
25
Au
g
l1
0
125
100
75
50
25
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29
Ju
Sediment discharge (kg/m/d)
Jefferson Fire con’t:
-1st summer: <10% plant cover, few grasses
-Substantial deflation– had to adjust equipment.
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Erodibility quantified through threshold wind speeds:
•hard to measure on unburned sites
•quite variable in time
•Sankey, Germino, Glenn (2009, JAE)
High variability in thresholds of erodibility following fire:
Why….is it surface moisture variability?
Sankey et al.
2009b, in Aeolian
Research
Wagenbrenner, Germino et al., accepted to Aeol Research
This event corresponded with decrease in soil moisture and loss of darker fertile
soil, changes in hydrologic conductivity
Dust was evident in MODIS satellite imagery
From the 2010 Jefferson Fire, Idaho:
Jefferson fire site: transformations
Abundant pedestals on burn
Neighboring unburned site
High density of shrub stems on
burned area
Halogeton and surface crust
after 9 months
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Haboob hits Boise, 5Aug2012
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Data ofDCEW
Sondra
Miller, T, Groom, T
Tree Line Site
Anderson; Boise State University
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-2
-1
Flux (mg m d )
Sampler A
Sampler B
100
50
0
17-Jul-12
24-Jul-12
31-Jul-12
07-Aug-12
Sample Collection Date
14-Aug-12
Generating models requires observations,
Monitoring requires appreciation of diversity of dust storm types and
basic weather/climate info. From Nat’l Center for Atmo. Research,
“Comet” program:
Bringing weather risk information into the realm of decision making
Risk cost vs. restoration benefit of soil disturbances after fire
From Mark Miller, for Milford Flats UT:
Threshhold
effects of fire
size on erosion:
not all areas
vulnerable
Grey: #snow-free days in
observation period
Open: #days that erosion was
substantive
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Outlook for 2012
Much burned area, dry fall but low wind?, winter?
USDA NIFA Grant, starting Jan 2013
Weather data and forecasting applications for management of
ecological site transitions
S Hardegree, J Abatzglou, M Brunson, M Germino
1. Database of historical meteorological information in support of
adaptive‐management planning and validation of
forecast‐modeling applications.
2. Seasonal forecasting tool for rangeland restoration planning.
3. Determine climatic thresholds for successful rangeland seeding
4. Determination of weather thresholds for soil stability
5. Supplementation of Ecological Site Descriptions with
climatological, weather and soil stability information
6. Identification of strategies to facilitate adoption of
weather‐centric management and forecasting strategies by land
management agencies and professional restoration planners.
Forthcoming data sources:
NASA’s SMAP: Soil Moisture Active/Passive
-planned collaboration with Lejo Flores, BSU Geology Dept.
-http://smap.jpl.nasa.gov/
-forthcoming (2014?)
-weekly; exact time/space repeats
-uses a radar(SAR)+radiometer combo (L-band)
Matt’s priority suggestions for climate and weather data needs for
rangelands:
Parameters like mean air temperatures are important, but
ecosystems are changing considerably with:
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Sequences of conditions affecting fire, erosion, and restoration
Wind – higher temporal resolution required.
Soil water – perhaps possible via integration with remote imagery
Parameters that aid in estimating the microclimate of soil surfaces
(eg. net radiation, wind).
• Snowcover.
The end
mgermino@usgs.gov