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The 2015 RPA Assessment Update of:. Rangeland Trends and Projections. Matt Reeves, Research Ecologist USDA, Forest Service, Research & Development Rocky Mountain Research Station. Contributors of data or ideas: Dominque Bachelet; MC2 projections
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The 2015 RPA Assessment Update of: Rangeland Trends and Projections Matt Reeves, Research Ecologist USDA, Forest Service, Research & Development Rocky Mountain Research Station Contributors of data or ideas: Dominque Bachelet; MC2 projections University of Montana; Biome BGC administration Rob Lankston; Close colleague and programmer
Outline ◦ Overview of RPA Assessments ◦ Some topics covered in 2015 update ◦ Glimpse of work in 2020; selected work with linkages to land managers and planners
What is the RPA Assessment? • • The Forest and Rangeland Renewable Resources Planning Act • of 1974 mandates a national report (the RPA Assessment) on • the status and trends of renewable resources every ten years. • The Assessment provides a snapshot of current U.S. forest and rangeland conditions and trends on all ownerships; identifies drivers of change; and projects 50 years into the future. RPA Assessment Overview
Climate change: rangeland production ◦ • Rangeland production is critically important: • Dictates stocking rate • Key indicator of health • Key indicator of sustainability • In a sense land capability can be viewed as essential for mankind • Basis for sequestration Rangeland base; for me Reeves, M.C., J. Mitchell. 2011. Extent of Coterminous US Rangelands: Quantifying Implications of Differing Agency Perspectives. Rangeland Ecology and Management. 64. 6: 1-12. RPA Assessment Overview
Climate change: rangeland production Earths’ climate will change Challenge is knowing: • When • Where • How • Why • Consequences Can use scenario’s RPA Assessment Overview
Climate change: rangeland production RPA Assessment Overview
Climate change: rangeland production - Nitrogen deposition as well Average A1B RPA Assessment Overview
Climate change: rangeland production RPA Assessment Overview
Climate change: rangeland production nitrogen deposition & CO2 Species composition Relative cover C3/C4 distribution C and N dynamics Disturbances Link C and N with plant/litter/soil Reeves, M., Moreno, A., Bagne, K., Running, S.W., 2014. Estimating the effects of climate change on net primary production of US rangelands. Clim. Change 126, 429–442.
Climate change: rangeland production Mean of A1B, A2, B2 Std. dev. of A1B, A2, B2 RPA Assessment Overview
Climate change: rangeland production Mean of A1B, A2, B2 Std. dev. of A1B, A2, B2 RPA Assessment Overview
Climate change: rangeland production Mean of A1B, A2, B2 Std. dev. of A1B, A2, B2 RPA Assessment Overview
Climate change: rangeland production In the North ~ 28% increase In the South -10% decrease RPA Assessment Overview
Forage quantity Climate change: rangeland production Large precipitation events can mitigate desiccation on some sites Northern areas increase Npp despite increased aridity Npp increased ~ 30 – 35% Our projections indicate ~ 28% increase across similar CO2 concentrations RPA Assessment Overview
Climate change: rangeland production ◦ Northern regions fare relatively better ◦ Higher elevation areas receive a pulse ◦ Southwestern U.S. is expected to be most vulnerable RPA Assessment Overview
Climate change: Cattle vulnerability 2001 to 2100 3 Scenarios (A2, A1B, B2) RPA Assessment Overview
Climate change: Cattle vulnerability Inter-annual variability in NPP RPA Assessment Overview
Climate change: Cattle vulnerability Inter-annual variability in NPP Used NPP projections to look at Inter-annual variability of forage RPA Assessment Overview
Climate change: Cattle vulnerability • HSI = 0.8 * Tair + RH * (Tair – 14.4) + 46.4 • Daily calculation • Is HSI ≥ Threshold? • All scenarios (Count # of days HSI exceeded threshold) T.M. Brown-Brandl et al. Livestock Science 105 (2006) 57–68 RPA Assessment Overview
Climate change: Cattle vulnerability MC2 – Dynamic Global Vegetation Model • Identify decadal direction and type of change: • Getting woodier? • Getting grassier? King, D. A., Bachelet, D. M. and Symstad, A. J. (2013), Climate change and fire effects on a prairie–woodland ecotone: projecting species range shifts with a dynamic global vegetation model. Ecology and Evolution RPA Assessment Overview
Climate change: Cattle vulnerability Heat Stress Index (HSI) Forage Quantity Forage Dependability Vegetation Type Change Classify Change Into Categories RPA Assessment Overview
Climate change: Cattle vulnerability 2060 2100 RPA Assessment Overview
Climate change: Cattle vulnerability 2060 2100 RPA Assessment Overview
Climate change: Cattle vulnerability 2060 2100 RPA Assessment Overview
Climate change: Cattle vulnerability ◦ Northern areas relatively less vulnerable ◦ Southwestern US relatively more vulnerable ◦ ◦ No adaptations evaluated No accounting for surface water, results may be conservative Reeves, M.C., K. Bagne, J. Tanaka. 2017 [in press]. Potential Climate Change Impacts on Four Biophysical Indicators of Cattle Production from Western US Rangelands. Rangeland Ecology and Management. RPA Assessment Overview
Climate change: Cattle vulnerability ◦ Projections ( for 2020 assessment) e.g. RPA Assessment Overview
Climate change: Cattle vulnerability ◦ Projections ( for 2020 assessment) e.g. RPA Assessment Overview
Climate change: Present day indicators? US Drought monitor composite 2000-2015 Warmer tones = greater cumulated drought RPA Assessment Overview
Degradation assessment …a reduction in the quantity or nutritional quality of the vegetation available for grazing… …a permanent, irreversible decline in the rate at which vegetation produces forage for a given input of rainfall… (Abel and Behnke 1996) Ambiguous UNCCD; Only degradation If management objectives are considered …a decline in land quality caused by human activities… RPA Assessment Overview
Degradation assessment Here: Degradation is the decline in vegetation productivity at a site relative to similar sites existing in like ecological domains with the same biotic potential. RPA Assessment Overview
Degradation assessment RPA Assessment Overview
Degradation assessment RPA Assessment Overview
Degradation assessment Is the difference between slopes significant from 0? RPA Assessment Overview
Degradation assessment Is the difference means significant? RPA Assessment Overview
Degradation assessment ◦ Overall, only ~ 7% of US rangelands exhibit degraded capacity Reeves and Baggett. 2014. A remote sensing protocol for identifying rangelands with degraded productive capacity. 43: 172-182 RPA Assessment Overview
Degradation assessment Prairie dog towns: (Courtesy of MT Fish Wildlife & Parks) RPA Assessment Overview
Trends in production: 2020 Assessment ◦ ◦ ◦ ◦ Although systemic degradation not found, production trends are notable • Rangeland production is critically important: • Dictates stocking rate • Key indicator of health • Key indicator of sustainability • In a sense land capability can be viewed as essential for mankind • Basis for sequestration No publically available systematic monitoring system available We therefore use our Rangeland Vegetation Simulator (RVS) to monitor and report on productivity at a national scale. RPA Assessment Overview
Trends in production: 2020 Assessment Annual Production 2000 – 2016; the Rangeland Vegetation Simulator RPA Assessment Overview
Trends in production: 2020 Assessment ◦ • Rangeland production trends (2000 – 2016) • Prototyped in R4 and R5 RPA Assessment Overview
Trends in production: 2020 Assessment • Drivers of production / stressors • Uncharacteristic Fire Regimes: • Drought • Development pressures RPA Assessment Overview
Trends in production: 2020 Assessment Areas of drought resistance/vulnerability RPA Assessment Overview
Trends in production: 2020 Assessment Drought impacts on production RPA Assessment Overview RPA Assessment Overview
Trends in production: 2020 Assessment Drought impacts on production RPA Assessment Overview RPA Assessment Overview
Trends in production: 2020 Assessment Drought impacts on production RPA Assessment Overview
Trends in production: 2020 Assessment LMNG (Strength) S. California (weakness) Kiowa – Rita Blanca (Extreme variability) RPA Assessment Overview RPA Assessment Overview
Trends in production: 2020 Assessment S. California (weakness) RPA Assessment Overview
Trends in production: 2020 Assessment Kiowa – Rita Blanca (Extreme variability) RPA Assessment Overview
Trends in production: 2020 Assessment Kiowa/Rita Blanca National Grasslands (Avg. ~ 25% variability) RPA Assessment Overview
Trends in production: 2020 Assessment Kiowa/Rita Blanca National Grasslands (Avg. ~ 25% variability) RPA Assessment Overview
Trends in production: 2020 Assessment Kiowa/Rita Blanca National Grasslands (Avg. ~ 25% variability) 2.5x RPA Assessment Overview