Green Glacier: The Looming Threat to the Oklahoma Beef Industry and Rural Communities

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1 Green Glacier: The Looming Threat to the Oklahoma Beef Industry and Rural Communities Sam Fuhlendorf, Regents Professor and Groendyke Chair in Wildlife Conservation Natural Resource Ecology and Management Oklahoma State University 1

2 Duck and Fletcher 1943 West East 2

3 West East West East 3

4 West East West East 4

5 West East Oklahoma Rangelands Semiarid Shrub Climate Forest Humid Sand Shortgrass prairie Savanna Soil Texture Mixed-grass prairie Tallgrass prairie Clay 5

6 The grass is at times green and short and at other times tall and white.. nothing but bare prairie, which becomes confused in the distance with the smoke of burning grass. Washington Irving Expedition, 1832 Near Stillwater OK Oklahoma Rangelands Semiarid Shrub Climate Forest Humid Sand Shortgrass Savanna prairie Eastern Redcedar Soil Texture Mixed-grass prairie Tallgrass prairie Clay 6

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8 From the Dust Bowl to the Green Glacier Stillwater, OK Sonora, TX Engle et al

9 Objectives Review impacts of cedar invasion Briefly review research on cedar Present a model developed to address the following questions: What causes the invasion? How long does it take? How do you manage it? How often is fire needed to keep it out? Are there alternatives? Thoughts on management Historical Stocking Rate Decline Sonora Experiment Station Animal Units/Section <10 % cover Of Woody Plants Animal Science Focus >50 % cover Of Woody Plants Range Mgt took over Year 9

10 Economic Returns Stillwater, OK. $/acre Dollars ($) Pasture Pasture Year Prescribed Fire Dates in Pasture 1 No fire in Pasture 2 10

11 Lesser Prairie-Chicken Petitioned October, 1995 Listed in 2014 Increase in trees is 15 times greater on landscapes with declining populations than on landscapes with stable populations- Woodward et al. 1999, Fuhlendorf et al. 2001) 11

12 Birds/40 ha Abundance of Grassland Birds y = ( x) 2 r 2 = 0.39 P = Eastern redcedar cover (%) Zou et al Hydrological Processes 12

13 Human Health allergies cost $2 Billion a year in US Van De Water and Levetin 2001 Eastern Redcedar Pollen Grains/cubic meter of air Peak Concentrations Season Total Year Wildfire Danger KOCO Oklahoma City Possum Kingdom Texas Texas Wildfires Image Gallery 13

14 What have we studied about cedar? Seed production per tree Chavez-Ramirez 1992, Smeins and Fuhlendorf 1997 Seed dispersal by wildlife Chavez-Ramirez 1992 Seedling germination rates- Smeins and Fuhlendorf 1997 Seedling survival response to grazing- Smeins and Fuhlendorf 1997 Growth rates of cedar- Blomquist 1990, Fuhlendorf 1992, Engle & Kulbeth 1992, Smeins & Fuhlendorf 1997 Overstory / understory relationships- Engle et al. 1987, Fuhlendorf et al Grazing influence on woody plant cover Fuhlendorf and Smeins 1997, Allred et al Influence of grazing on herbaceous community Fuhlendorf and Smeins 1997, Fuhlendorf et al Influence of weather patterns Fuhlendorf et al Effects of fire on juniper mortality Wright and Bailey 1992 Patch Dynamics- Grazing model (Fuhlendorf et al. 2008) Mid-Grass Herbaceous Biomass Weather Patterns Short-Grass Grazing Landscape Dynamics Cedar invasion model (Fuhlendorf et al. 1996) Seed Dispersal Seed Production Juniper Size and Density Mortality Fire Intensity Fire Frequency 14

15 Background on sites Low Productivity Site (Sonora, TX) 20 in PPT Shallow Soils Limestone Derived Southwestern edge of Edward s Plateau Southern edge of Great Plains Savanna of Oak/Juniper/Mixed Prairie Focus on the expansion of Juniperus ashei 15

16 Background on sites High Productivity Site (Stillwater OK) 33 in PPT Shallow Soils Along edge of Crosstimbers/Tallgrass Prairie Savanna of Oak/Juniper/Tallgrass Prairie Plant communities are limited by soil texture- sandstone derived soils= Oak Focus on the expansion of Juniperus virginiana into grassland plant communities 16

17 Herbaceous Biomass (percent of maximum) Ungrazed and No Fire Potential Forage Remaining Forage Tree Density Year Large Trees/ac (>6m dia.) 17

18 Herbaceous Biomass (percent of maximum) Ungrazed with a 10 year fire return interval (FRI) Potential Herbaceous Biomass Remaining Herbaceous Biomass Tree Density Year Large Trees/ac (>6m dia.) So, when productivity is low, even moderate grazing can reduce herbaceous biomass enough to limit the success of prescribed fires in the maintenance of grassland ecosystems. What about cross-site comparisons? 18

19 No Grazing Potential Herbaceous Production (%) Low productivity High productivity No Fire Fire Return-Interval (yrs) Moderate Grazing Potential Herbaceous Production (%) Low productivity High productivity No Fire Fire Return Interval (yrs) 19

20 Heavy Grazing Potential Herbaceous Production (%) Low productivity High productivity No Fire Fire Return Interval (yrs) Fire Return Interval (years) Fire frequency required to maintain grassland production for 150 years Ungrazed Moderate with 1-year rest Moderate with no rest Grazing Treatment Heavy with 1-year rest Heavy with no rest 20

21 Assumptions: Grassland Ecosystems If the first few fires are missed then it will take much more fire and perhaps other more intensive management to maintain forage production Assumptions: Grazing is with Cattle not goats- Fuhlendorf et al

22 Assumptions: Grazing and fire occur uniformly on the same place Fuhlendorf & Engle 2001, 2004, Fuhlendorf et al. 2009, Allred et al. 2011, etc Assumptions: all fires in the model were not considering extreme fires A. Grassland State? B. At-risk State Phase C. Woodland State Nuclear Fire Single Fire 22

23 So, What do we do about it? Ortmann et al

24 As property sizes get smaller and trees get bigger it gets more expensive to control Eastern redcedar Number of times burned in the past 11 years Carol Blocksome - KSU 24

25 What limits the application of prescribed fires on private property? FEAR of: Damage to private property Risk to human safety Soil erosion Less important Smoke Aesthetics Timber production Elmore et al

26 Diverse fire community Public safety officers Private land managers Media and the public Prac oners Fire science and informa on needs Public land managers Contractors Policy makers Researchers Conclusions Cedar is a leading threat to natural resources Fire suppression is the primary driver Grazing has little or no direct effect Most efficient management is periodic fire before you have a problem Cedar-based products? Alternative= Extreme fires, goats, heterogeneity Oklahoma is building a unique grass-roots social structure for management 26

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