Plant Sciences Special Seminar 6/7/2012

Transcription

1 Healthy Rangeland Watersheds and Productive Enterprises: Why Not? Ken Tate, UCD Plant Sciences Research and extension support for stakeholders to enhance rangelands Healthy Rangelands, Ranches & Communities Leslie Roche, Rob Atwill, Valerie Eviner, Randy Dahlgren, Toby O Geen, Mark Lubell, Mel George, UCCE Advisors, UCANR RECs, CCA, CFBF, USFS, NRCS, CRCC, NRCS, and many ranching families. Partnerships among scientists, managers, conservationists, and policy makers is providing the most relevant knowledge for managing rangeland systems. ~40 million acres 50% private 50% public CA Rangelands Research Application sage steppe Briske et al annual grassland oak woodland Supports a $3B livestock industry Safe Water to Drink and Irrigate Water and meals to tens of millions Ken Tate, rangelandwatershed.ucdavis.edu 1

2 Biodiversity 300 vertebrate species 5000 invertebrate species 0 plant species SOCIAL ECONOMIC ECOLOGICAL SYSTEM CA tiger salamander purple needle grass Conflicting opinions about ranching and sustaining Clean water Soil health Riparian health Sensitive species We focus research and extension on the balancing act management must sustain multiple, interdependent ecosystem services. Habitat Water Nutrient Cycling Open Space Ranch Profit Water quality Weeds Soils Riparian Wildlife Carbon Tradeoffs Optimizing ranch profit may diminish ecosystem services, and perhaps sustainability. Habitat Water Nutrient Cycling Open Space Ranch Profit Cutts et al., In Prep. High Priority Low Survey of 1500 CA ranchers Ken Tate, rangelandwatershed.ucdavis.edu 2

3 Plant Sciences Special Seminar 6/7/2012 ECOSYSTEM SERVICE TRADEOFFS WOODY THINNING Grass, not oaks, makes your cows fat Hardwood Rangelands Thinning woody plants a common practice to increase forage. Oak woodland Oak savanna UCCE 1960 s SFREC Research Station 2500ha; m SN Gravelly Loam Foothill ES Undisturbed Woodland >50% Canopy Undisturbed Woodland >50% Canopy 26 ac / auy 2.20 Blue Oak Savanna <50% Canopy 13 ac / auy Annual Grassland Blue Oak Savanna <50% Canopy Annual Grassland ac / auy Ecosystem Service: Biotic Integrity Ecosystem Service: Agricultural Production Metric: Carrying capacity Roche et al. In Prep. Metric: Diversity (H ) Roche et al. In Prep. A SOIL BALANCE CAN BE FOUND Woodland Bird Habitat Undisturbed Woodland >50% Canopy 55 g TC / kg 3.9 g TN / kg Annual Grassland Woodland Agricultural Productivity Infiltration Blue Oak Savanna <50% Canopy 42 g TC / kg 3.2 g TN / kg 30 g TC / kg 2.5 g TN / kg Converted grassland Metric: TC & TN Ken Tate, rangelandwatershed.ucdavis.edu Nutrient Cycling Diversity Soil Carbon Sequestration Ecosystem Service: Nutrient cycling Roche et al. In Prep. Open grassland Roche et al. In Prep. Selectively thinned Savanna (<50% canopy) 3

4 The balance can be tipped the other way as well. Regulatory Pressure Development Opportunity $ Water Habitat Nutrient Cycling Open Space The balance can be lost. Ranch Profit final sale to new enterprise We can manage for healthy rangelands and productive livestock enterprises. a source of pathogens in drinking water? C. parvum E. Coli O157:H7 mid-1990s I can be good.i promise! 15+ years of studies on microbial WQ Water quality Weeds Soils Riparian Wildlife Carbon?? C. parvum E. Coli O157:H7 High Priority Low Cutts et al., In Prep. Survey of 1500 CA ranchers Salmonella Ken Tate, rangelandwatershed.ucdavis.edu 4

5 Microbial Water & Cattle Grazing Organizing Our Knowledge Microbial Water & Cattle Grazing Organizing Our Knowledge Factors that increase risk of water pollution with pathogens Factors that increase risk of water pollution with pathogens High stocking rates more fecal load more defecation in water, near water, and runoff areas more runoff and pathogen transport High stocking rates more fecal load more defecation in water, near water, and runoff areas more runoff and pathogen transport Herd infected calves < 4 mo calving during rainy long calving Factors that reduce risk of water pollution with pathogens Factors that reduce risk of water pollution with pathogens Moderate Grazing set cattle numbers in balance with forage production enhance soil hydrologic health Tate, Atwill, et al. Moderate Grazing set cattle numbers in balance with forage production enhance soil hydrologic health Tate, Atwill, et al. Manage Calving keep calves < 4 mo away from water offset calving from rainy shorten calving Microbial Water & Cattle Grazing Organizing Our Knowledge Microbial Water & Cattle Grazing Organizing Our Knowledge Factors that increase risk of water pollution with pathogens Factors that increase risk of water pollution with pathogens High stocking rates Herd infected Distribution space High stocking rates Herd infected Distribution space Distribution time more fecal load more defecation in water, near water, and runoff areas more runoff and pathogen transport calves < 4 mo calving during rainy long calving cattle defecate in water cattle defecate near water cattle defecate in runoff areas more fecal load more defecation in water, near water, and runoff areas more runoff and pathogen transport calves < 4 mo calving during rainy long calving cattle defecate in water cattle defecate near water cattle defecate in runoff areas cattle defecate near water during rainy cattle defecate in runoff areas during runoff Factors that reduce risk of water pollution with pathogens Factors that reduce risk of water pollution with pathogens Moderate Grazing Manage Calving Manage Cattle Distribution Moderate Grazing Manage Calving Manage Cattle Distribution Manage Grazing Time set cattle numbers in balance with forage production enhance soil hydrologic health keep calves < 4 mo away from water offset calving from rainy shorten calving provide off stream water place supplemental feed away from water and runoff areas create riparian/runoff pastures create buffer strips set cattle numbers in balance with forage production enhance soil hydrologic health keep calves < 4 mo away from water offset calving from rainy shorten calving provide off stream water place supplemental feed away from water and runoff areas create riparian/runoff pastures create buffer strips reduce cattle grazing near water during rainy reduce cattle grazing in runoff areas prior to and during runoff Tate, Atwill, et al. Public Lands Grazing and WQ fast forward 15 years waste found to foul Sierra waters Sacramento Bee, Apr 2010 USFS Public Grazing Allotments in CA 500 grazed allotments 8,000,000 acres 430,000 Animal Unit Months ~70, cattle Ken Tate, rangelandwatershed.ucdavis.edu 5

6 Summer Grazing Allotments Studied 155 WQ Sample Collection Sites 743 Samples Collected and Tested Test for fecal indicator bacteria, N, and P National Forest Allotment Name No. Sample Sites Klamath Mill Creek 8 Klamath Shackleford 17 Shasta Trinity Bartle 17 Shasta Trinity Upper South Fork 15 Shasta Trinity Bear Creek 12 Shasta Trinity Indian Valley 13 Plumas Grizzly Valley Community 7 Plumas Grizzly Valley 15 Tahoe Smithneck 10 Tahoe Independence 18 Stanislaus Bell Meadow 12 Stanislaus Jawbone 11 cfu Fecal coliform standard for recreation. 235 cfu E. coli standard recommended by EPA. Fecal coliforms > 10 % mean 82 cfu median 21 cfu Indicator E. coli >235 3 % mean 40 cfu median 8 cfu Kromschroeder et al., In Prep Jun Jul Aug Sep Oct Nov Nutrients PPB TN NO 3-N NH 4-N TP PO 4-P Mean Concern Pa arts per Billion 600 total N nitrate as nitrogen ppb Jun Jul Aug Sep Oct Nov Parts per Billion Riparian Health Riparian areas once considered sacrifice areas to optimize upland forage harvest. Riparian Health Survey of 130 Grazed Riparian Areas EPA CDFG Stream Health Assessment Grazing Management Cross section of grazed rangeland streams. stability Off-site water, herding,, frequency, fencing, etc. Cascades, Sierra Nevada, Site Characteristics and Coast Range. Gradient of stream health and grazing management. Becchetti et al., In Prep. fish habitat macroinverts. Overall Health Score 0 5 poor 6 10 marginal suboptimal optimal Elevation, channel slope, substrate, watershed disturb., past disturb., etc. Ken Tate, rangelandwatershed.ucdavis.edu 6

7 Practices and Riparian Health Off stream attractants such as water tanks and supplement days/yr (+). Herding to control utilization and time spent in riparian i area days/yr (+). Rest period duration days/yr (+). Cattle density (cows/ac) during grazing bouts ( ). Frequency of grazing bouts per year ( ). YOSEMITE TOAD CA DFG Species of Special Concern and nominee for federal endangered species status Central/southern Sierra Nevada mountains (~ ft) Mountain meadows Breeding and rearing habitat Is grazing a problem?? Mixed effects regression analysis CONCEPTUAL MODEL RESULTS Mixed effects Bayesian structural equation model Productivity Productivity 3.74** Meadow wetness Utilization Toad Presence Meadow wetness -0.29* 0.54** Utilization NS Toad Presence Roche et al Roche et al ** 0.43* Toads respond to meadow wetness, rather than grazing intensity. Likely due to different habitat preferences of cattle and toads. CONCEPTUAL MODEL: : THE BIG PICTURE Historic land use Productivity Climate change 3.74** Predator dynamics We can achieve multiple outcomes goals must be set, adaptive site-specific specific management, toolbox no silver bullet. Meadow wetness Upland watershed mgmt Restoration Utilization NS Toad Presence Infectious diseases Airborne chemicals Habitat Water Nutrient Cycling Open Space Ranch Profit Conservation of this sensitive species will require a more comprehensive approach than focusing solely on grazing management. Some synergies i.e. Yosemite toad, nutrients Some tradeoffs i.e. Woody thinning, microbial WQ Ken Tate, rangelandwatershed.ucdavis.edu 7

8 EMBRACE THIS COMPLEX SOCIAL ECONOMIC ECOLOGICAL SYSTEM! NEXT STEPS: On-Ranch Surveys Management 60 ranches in CA and WY. Ranch enterprise scale goals, management, opportunities, constraints, economics, etc. Ecosystem Services Measure a suite of ecosystem services on each ranch. Connect the social, economic, ecological dots on management decision making, implementation and outcomes. NEXT STEPS: Stakeholder Prescribed Grazing Study UC Sierra Foothill Research and Extension Center USDA ARS Central Plains Research Center California Rangeland Watershed Laboratory Google rangeland watersheds Rancher, range manager, and conservation professionals. Prescribe management goals and management (treatments). We implement, monitor, adapt with stakeholder advice. SFREC Stakeholder Prescribed Grazing Project Focus Group Meeting Ken Tate, rangelandwatershed.ucdavis.edu 8