2005 Annual Report
To address the challenges of a changing environment, due in part to the release of GHGs into the atmosphere, we will assess/project changes in the structure and functioning of Great Plains grasslands due to the interactive effects of elevated CO2 and warming on primary production, N and C cycling, and plant community dynamics, including invasive weeds. This will be done in a field Free Air CO2 Enrichment (FACE) and warming experiment conducted in a native northern mixed grass prairie, with some areas inter-planted to locally important perennial weeds. Some controlled environment studies will be conducted to evaluate specific mechanistic responses, like plant recruitment or N cycling. Modeling exercises will also be conducted from previous CO2 field enrichment experiments to predict long-term responses of Great Plains grassland ecosystems to global change. The management question related to reducing GHG emissions will be addressed in additional experiments evaluating legume inter-seeding into grasslands as a tool to increase carbon storage, and grazing practices. In particular, we will be investigating how legume inter-seeding affects N cycling among associated plants and the microbial community in an effort to determine the impact on the land-atmosphere GHG exchange as well as on carbon storage. We will also be evaluating the effects of different stocking rates on C and N cycling.
Build and test FACE system prototype (July-Oct, 2004) Assess legume inter-planting methods (April-June, 2005) Final testing of FACE system; installation (2005) Establish plots and transplant legumes (May, 2005) Seed plots with weed species (September, 2005) Annual and seasonal measurements (2006-2010) Analysis, synthesis, and manuscript development and submission for 1st 3 years of project (2008, 2009) Modeling of SGS and TGP CO2-enrichment studies (2004, 2005) Results on modeling water relations/forage responses reported in manuscripts (2006, 2007) Data summary/synthesis of Bowen Ratio CO2 flux, send to ARS El Reno (2007) Collaborate with ARS El Reno on modeling weather-driven CO2 fluxes, develop manuscript (2008) Submit manuscript on weather-driven CO2 fluxes (2009)
Objective 2. Develop management strategies that optimize responses of semi-arid rangeland to global change and minimize emission of greenhouse gases (GHGs).
Collect baseline soils data from 2 new NP205 grazing management studies (2004) Repeat soil sampling and analyses from above (2009) Repeat soil sampling and analyses from long-term grazing management studies (2004, 2007) Results on long-term grazing impacts on soil C and N cycling developed into manuscripts (2005, 2008) Baseline soil sampling on private ranches (2004) Bi-weekly assessment of alfalfa establishment in a private ranch study (2004, 2005) Repeat soil sampling and analyses in a private ranch study (2009) Repeat soil sampling and analyses in a private ranch study (2006, 2009) Trace gas measurements at HPGRS and in a private ranch study (2004, 2006-2008)
Plant Growth and Forage Quality Responses to UV Radiation. Collaborative research was undertaken with the Dept. of Forest, Rangeland and Watershed Stewardship, Colorado State University, Fort Collins, CO; the Dept. of Soil, Water, and Climate, University of Minnesota; the Dept. of Biological Sciences, University of Northern Colorado; the USDA UV-B Monitoring and Research Program, Colorado State University; and the ARS Soil-Plant-Nutrient Research Unit, Fort Collins, CO, to manipulate UV radiation in a natural field setting to determine the effects of increasing surface UV radiation on vegetation. UV levels were manipulated by constructed structures over native shortgrass prairie that either passed or blocked wavelengths shorter than 370 nanometers. The overall effects of UV radiation were to decrease forage quantity but to increase quality. Such UV-induced changes in forage quality could speed up organic matter decomposition, thereby altering carbon dynamics such that the ecosystem’s ability to store C is reduced. Significant species differences in biomass sensitivity to UV were also apparent, and the species with the greatest sensitivity is one that is important in stabilizing the system. The results suggest that increased surface UV radiation will have important consequences on ecosystem nutrient dynamics and community species composition that must be considered in evaluations of climate change impacts on native grassland ecology.
Nov, 2004: invited seminar speaker to Ecology Seminar Series at the University of Nevada, Reno to discuss impact of CO2 on grassland ecology.
Feb., 2005: invited presentations at symposium entitled USDA-ARS Global Change Research on Rangelands and Pasturelands presented at SRM Annual Meeting, Fort Worth, Texas. Individual talks were - Management effects and potential for rangeland carbon sequestration; Grazing management effects on inorganic C storage in rangelands; Influence of CO2 enrichment on plant community and soils systems in semi-arid rangelands.
A summary manuscript of these and other invited talks was developed into a manuscript and submitted to Rangelands under the same title.
May, 2005: invited presentation entitled, “Using Field Experiments and Modeling to Understand how Shortgrass Steppe Vegetation Will Respond to Rising Atmospheric CO2 and Global Change” at TERACC- and Diversitas-sponsored Global Change/Biodiversity Workshop in Paris, France, to improve interactions among global change ecologists and climatologists who work at several different spatial scales.
June, 2005, co-authored with the USDA Forest Service. Oral presentation “Impact of Climate Change on Western Rangelands” at USDA Forest Service Workshop in Eugene, Oregon, Bringing Climate into Natural Resource Management.
Sept., 2005: platform lead-off speaker for “Impacts of High CO2 on Land and Ocean Ecosystems” at the Seventh International Carbon Dioxide Conference, Boulder, CO.
Two papers titled “Differences in labile pool C and N dynamics in the surface soils of two semi-arid rangeland ecosystems”, and “Contribution of grass crowns and surface soil roots to rangeland ecosystem C dynamics” at the American Society of Agronomy Annual Meeting in Seattle WA, November 1-4 2004.
Soil Resource Management Workshop, Dallas TX, February 22-25, 2005.
Mentored three Colorado State University graduate students in using the proper protocols for collecting, processing and analyzing soils from rangelands and riparian grazing areas.
Co-author on a poster “Land-use impacts on carbon and water flux on the Shortgrass Steppe in Eastern Colorado - Preliminary Results” at the Shortgrass Steppe Symposium, Fort Collins CO, January 14 2005.
Co-author on a poster “Shortgrass steppe ecosystem productivity” at the Shortgrass Steppe Symposium, Fort Collins CO, January 14 2005.
Seminars to producer groups at six locations within Wyoming on the potential of yellow-flowering (Medicago sativa ssp. falcata) alfalfa in rangeland interseeding. The seminars were organized by the University of Wyoming Extension Service, local conservation districts and the Natural Resources Conservation Service. The seminars included information on how to history of the plant subspecies, interseeding methodologies, production potential, forage quality enhancement, and enhancement of soil organic carbon storage. Significant interest has been shown by producers and land managers in the use of this subspecies to enhance rangeland production and forage quality. Commercially produced seed was available for the first time and over 9000 lbs (entire available supply) of seed was marketed within a couple of months; demonstrating the interest. ARS scientists, the rancher (supplied seed stock), and NRCS Plant Materials personnel are presently preparing a release of this material as the “Smith Ranch Alfalfa” so that a common genetic base will be established.
July, 2005, supplied reprints and input to the Dept. Environmental Science, University of Botswana, Botswana concerning grassland global change research to assist in a summary report of ecosystem responses to global change for the current Intergovernmental Panel on Climate Change (IPCC) Report. This report is expected to be released to the public within a year, and will be used by world governments and policy makers to develop global change policy.
Revkin, Andrew C. 2004. U.S. report turns focus to greenhouse gases. The New York Times, August 26, 2004.
2005. More forage might be worth less. Agricultural Research, August 2005, p 23.
Sian Mooney, George F. Vance, Justin Derner, and Gerald Schuman. 2005. Collaborative Research-Committee Participation Furthers Carbon Sequestration Research. pp. 44-45. In: Reflections, University of Wyoming, College of Agriculture, May 2005, University of Wyoming, Laramie, WY.
134833 Morgan, J.A. 2001. Ecosystems and their goods and services, Chapter 5: Climate Change 2001. pp. 235-342. In: J.J. McCarthy, et.al. (eds). The third assessment report of the intergovernmental panel on climate change (IPCC), Cambridge University Press, Cambridge, UK.
184263 Pendall, E.L., King, J.Y., Mosier, A.R., Morgan, J.A., Milchunas, D. 2005. Stable isotope constraints on net ecosystem production under elevated CO2. pp. 182-198. In: L.B. Flanagan, J.R. Ehleringer and D.E. Pataki (eds) Stable isotopes and biosphere-atmospheric interactions: Processes and biological controls. Book Chapter. Elsevier, Inc., San Diego, CA.
170325 Follett, R.F., Schuman, G.E. Grazing land contributions to carbon sequestration. pp. 265-277. In: D.A. McGilloway (ed). Grassland: A global resource. XX Int’l. Grassland Congress, 25 June-1 July, 2005, Dublin, Irelad. Wageningen Academic Publishers, Wageningen, The Netherlands.
169125 Schuman, G.E., Derner, J.D. 2005. Management effects and potential for rangeland carbon sequestration. In: Proceedings Annual Society for Range Management meetings. CD Abstract #307. Fort Worth, TX, Feb. 2005.
170307 Norton, U., Morgan, J.A., Mosier, A.R., Derner, J.D. 2004. Trace gas emissions and soil C and N transformations following moisture pulses in sagebrush: Effects of invasive and native companion plant species. P. 358. In: Proceedings of the American Geophysical Union Fall meeting Abstracts.
170309 Norton, U., Morgan, J.A., Mosier, A.R., Derner, J.D., Stahl, P., Ingram, L.J. 2004. Trace gas emissions and soil C and N transformations following moisture pulses in sagebrush: Effects of invasive and native companion plant species. American Society of Agronomy Abstracts. Abstract 5328.
170990 Morgan, J.A. 2005. Influence of CO2 enrichment on plant community and soils systems in semi-arid rangelands. Society for Range Management meeting proceedings. Abstract #283.
176295 Reeder, S.J. 2005. Grazing management effects on inorganic C storage in rangelands. Society for Range Management Annual Meeting Abstracts. Special Symposium: Global change and rangelands/pastures: A state of the state. CDROM Abstract.
184913 Blumenthal, D.M., Chimner, R., Welker, J., Morgan, J.A., LeCain, D.R. 2005. Testing for evolution of increased competitive ability across species and functional groups. Ecological Society of America Annual Meeting Proceedings. August, Montreal, Canada. CDROM Abstract.
Gilmanov, T.G., Tieszen, L.L., Wylie, B.K., Flanagan, L.B., Frank, A.B., Haferkamp, M.R., Meyers, T.P., Morgan, J.A. 2005. Integration of CO2 flux and remotely sensed data for primary production and ecosystem respiration analyses in the Northern Great Plains: Potential for quantitative spatial extrapolation. Global Ecology and Biogeography 14:271-292.
Milchunas, D., Mosier, A.R., Morgan, J.A., Lecain, D.R., King, J.Y., Nelson, J.A. 2005. Elevated CO2 and defoliation effects on a shortgrass steppe: forage quality versus quantity for ruminants. Agriculture, Ecosystems and Environment. 111:166-184.
Liebig, M.A., Morgan, J.A., Reeder, S.J., Ellert, B.H., Gollany, H.T., Schuman, G.E. 2005. Greenhouse gas contributions and mitigation potential of agricultural practices in northwestern USA and western Canada. Soil & Tillage Research 83:25-52.
Derner, J.D., Tischler, C.R., Polley, H.W., Johnson, H.B. 2005. Seedling growth of two honey mesquite varieties under CO2 enrichment. Rangeland Ecology and Management. 58:292-298.