climate change – what we know & consequences management ... · climate change – what we...
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Climate Change – what we know & consequences› Climate› VegetationRecent trends for Arthur, NebraskaManagement implications› Tools› Decision support systems
Charles David Keeling
1928-2005
2002 Nat’l Medal of Science
Annual cycle due to photosynthesis and respiration of soils.
Long term trend due to emission of fossil fuels
IPCC Working Group I Report, Chapter 2, 2007
WHAT WE KNOW: Ice core sampling & other techniques indicate rising CO2 in Earth’satmosphere is a relatively new phenomenon.
Nutrients, H2O
CO2
Food, GloriousFood!
Any change in light, water, nutrients or carbon dioxide will alter plant growth.
Responses of plant functional group NPP to CO2 in the Colorado shortgrass steppe
Morgan et al., 2007. PNAS104(37):14724-14729
Responders & Mechanisms:
C3 vs. C4 photosynthesis
P. smithii seedling recruitment
A. frigida photosynthesis, soil water
40-fold increase inArtemisia frigidabetween 1997 & 2001!
Honey locust tree islands in Kansas Tallgrass Prairie.Present-day encroachment?Fire removal, climate change, CO2?(photograph courtesy of Alan K. Knapp).
Mesquite encroachment in SWover past two centuries
(photograph courtesy of ARS Jornada Experimental Range photo gallery).
WHAT WE KNOW: Global average surface temperature has increased 0.74 C (1.2 F) in the last hundred years. Rate of warming has doubled in the past 50 years.
Predictions indicate future accelerated & extreme warming.
IPCC 2007: WG1-AR4
Epstein, Gill, Paruelo, Lauenroth, Jia and Burke. 2002. J. of Biogeography 29:875-8
Modeled Future Relative Abundances (shrubs, C3, C4) in Grasslands of N & S America. Based on: • GCMs • Relative Abundance Equations
precip, temp, soil water
Based on observations & measurements obtained in the real world.
Approach does not capture CO2 response
Functional Plant Group Modeling
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1970-1999 2010-2039 change1 2040-2069 change2 2070-2099 change3
ºF
Period
Arthur, NebraskaPeriod-Mean Annual Temperature
ukmo_hadcm3.1.sresa1b
ukmo_hadcm3.1.sresa2
ukmo_hadcm3.1.sresb1
C3 g
rass
AG
B (g
m-2)
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20
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ctCtcTCT
C4 g
rass
AG
B (g
m-2)
0
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40ctCtcTCT
Tota
l AG
B (g
m-2)
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ctCtcTCT
2006 2007 2008
Prairie Heating & CO2Enrichment (Cheyenne)
c (current) & C (high) CO2t (current) & high (T) Temp
Heat can diminish CO2 benefit
C3 g
rass
AG
B (g
m-2)
0
20
40
60
80
ctCtcTCT
C4 g
rass
AG
B (g
m-2)
0
10
20
30
40ctCtcTCT
Tota
l AG
B (g
m-2)
0
20
40
60
80
100
ctCtcTCT
2006 2007 2008
Prairie Heating & CO2Enrichment (Cheyenne)
c (current) & C (high) CO2t (current) & high (T) Temp
Heat can diminish CO2 benefit
High CO2 & temp favors C4
-0.20
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0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1970-1999 2010-2039 change1 2040-2069 change2 2070-2099 change3
Inch
es p
er M
onth
Period
Arthur, NebraskaPeriod-Mean Annual Precipitation:
ukmo_hadcm3.1.sresa1b
ukmo_hadcm3.1.sresa2
ukmo_hadcm3.1.sresb1
IMPLICATIONS OF WHAT WE KNOW Longer growing seasonDesiccation due to warmingAltered hydrologic cycle
atmosphere holds more water vapor intense rainfall eventstiming (altered seasonal precipitation;
earlier loss of snow pack)some regions more drought-prone
Plant Species Change
Photo: Sam Cox
What About Weeds?Will climate changefacilitate invasion?
CC decreases suitability for native species
1) High seed production2) Effective dispersal3) Rapid growth4) High plasticity5) Rapid evolution
Dukes and Mooney 1999, Trends in Ecology and Evolution 14:135
http://www.hprcc.unl.edu/maps/atlas/index.php?product=100&type=c&p_option=13&action=viewmap
http://www.hprcc.unl.edu/maps/current/index.php?action=update_product&product=TDept
http://www.hprcc.unl.edu/awdn/soilm/index.php?station=a250369&plot_type=soilm&year=past&action=View+Plot
The Hydro-illogical cycleReflective and Predictive Web-based productsDecision Support Systems
http://drought.unl.edu/plan/cycle.htm
http://www.drought.unl.edu/dm/monitor.html
http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html
http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/page2.gif
http://www.cpc.ncep.noaa.gov/soilmst/img/cas_w_mon.lead1.gif
http://drought.unl.edu/vegdri/VegDRI_archive.htm
Model InputsSite name:Ranch size:Animal type (e.g. cattle):Weather type (e.g. historical)
GPFARM-RangeModel
Forage forecastWeather forecast sources:e.g. NOAA, NASA, IRI, OTHERForecast: V. Good, Normal, Poor
Forage (kg/ha)
April June Sep
1
23
Output
1: High
2: Moderate
3: Low
Stocking and Forage demand rates:
- The interface (next slide) enables User to run the GPFARM-range on the web.- The model outputs the monthly forage production.- Depending on stocking rate, the output shows periods of forage surplus/deficit.- Ranchers can adjust stocks to minimize forage shortages.
Andales et al. 2006
Stocking Rate!!!Good Stewardship!!!Plan!!!Flexibility/Adaptivity of livestock operations will be paramount› Kind, type and size of livestock› Within grazing season modifications in number of
grazing animals› Movement of livestock across geographic areasPredictive power and accuracy will be essential for operations› Reduce risk!