Basing Elk Population Limits on Direct Measurements of Vegetation - PowerPoint PPT Presentation

Basing Elk Population Limits on Direct Measurements of Vegetation Health and Use Patterns. By: Catherine Schnurrenberger, C.S. Ecological Surveys and Assessments, 11331 Star Pine Rd. Truckee, CA 96161. cadavis@ltol.com

Why do we need effective monitoring of elk impacts?  Elk numbers are increasing in Nevada  Elk are expanding their range  There is concern over competition with livestock and other wildlife species  It is easier to manage elk numbers before there are significant detrimental impacts

Elk in Nevada Past and Present McCullough, 1969 Historical Elk Distribution Current Elk Distribution Nevada

Set Clear Goals!!!  No reduction in livestock AUMs  Healthy Aspen stands  No impact on Mule Deer  Healthy Riparian areas  No direct competition with livestock  Protection of special-status species

What have we learned from past monitoring? 1. Need to verify elk use by, pellet counts, fecal analysis, sitings (NDOW, hunters, ranchers). 2. Need to sample plant communities of interest/concern. 3. Elk impact some vegetation types at lower population densities i.e. Aspen stands. 4. Need to incorporate impacts from livestock, wildlife, pathogens and wildfire 5. Need to account for herd movement and variability year to year. 6. Quantitative data is best, most defensible, easiest to compare year to year, but all observations are useful.

How have we monitored to achieve goals? Monitoring m ethod Goal Pellet counts, utilization and 1. No reduction in AUMs, 1. cover by desired species. no direct competition Stand structure data, pellet 2. with livestock counts, utilization and microhistal analysis. Healthy Aspen stands 2. Pellet counts, use on willows 3. Healthy riparian areas 3. and key species. No competition with 4. Pellet counts, utilization of 4. Mule deer key species and microhistal analysis.

Goose Creek Elk Management Area, BLM. 2006 Dinner Springs and Winecup Ranch wet meadow/riparian areas. Dinner Springs (SM17) use by cattle, >90%. WT-04 Private riparian land No signs of elk use here. not grazed by cattle for 5 years, detected 10-15% elk use on key graminoids.

Goose Creek 2006 Sites on left grazed by cattle, sites on right wildlife only. Average Use of Graminoids at Riparian Sites, 2006 Percentage of Key Graminoids 100 90 80 70 Utilized 60 50 90.00 83.90 40 30 20 10 0.00 13.50 0 SM-05 FALL 06 SM-17 FALL 06 SM-06 ( Rip) FALL WT-04 SUMMER 06* 06* Site and Season Monitored

Bruneau River 2003 Sand Creek little use on Deep Creek Riparian little elk gram inoids and regeneration use. of w illow s.

Bruneau River Mesic/Moist Meadow Sites, 2003 Tennesse Creek Mud Springs

Bruneau River Mesic/Moist Meadow Sites, 2003 Taylor Creek Row land

Graph of Cover at Bruneau River Mesic Sites, 2003 Percent Foliar Cover from Grasses and Forbs at Mesic or Moist Meadow Sites 1 0 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0 Cattle No Cattle Cattle Cattle No Cattle Bristol Springs Mud Springs Row land Taylor Creek Tennessee Creek

Bruneau River Elk Monitoring 2009 Deep Creek early Highest use on w hite spring trailing by elk w yethia

Jarbidge 2010 Low er W illiam s Basin Low er W illiam s Basin w illow dam age, little w illow hedging use on gram inoids

Jarbidge 2010 Caudle Creek w illow Cherry Creek w illow brow se by elk brow se by livestock

Elk Numbers in Different Areas Area Year Elk numbers Area sq. miles Elk density Bruneau River USFS 2003 650 250 2.6 Bruneau River USFS 2009 1,100 250 4.4 Bruneau River USFS Now 4,000 250 16.0 Jarbidge USFS 2010 1,000 270 3.7 Jarbidge USFS Now 2,500 270 9.3 Goose Creek BLM 2006 1,100 957 1.1 Goose Creek BLM Now 1,900 957 2.0

Upland Sagebrush/grassland  This vegetation type is important to livestock and wildlife.  This vegetation type is the most abundant throughout Nevada  AUMs may be based in part on the amount of key species: bluebunch wheatgrass, Idahoe fescue  Allowable use and on/ off dates often based on utilization of these key species

Monitoring production and utilization of key bunchgrasses, Goose Creek BLM 2006

10 20 30 40 50 60 0 Cattle Cattle Cattle Wheatgrass, Goose Creek BLM 2006 Cattle Percent Utilization on Bluebunch Cattle Cattle Cattle Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle No Cattle

Winter Use by Elk at Upland Sites, Bruneau River 2009 1 0 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0 Residual Current

Aspen as a Special Concern  Aspen stands are declining throughout the west.  Age class or stand structure data shows a lack of aspens in the 25 – 50 year age class (pole/ sapling or regenerative age class).  Impact on this age class is related to past grazing by livestock.  Elk browse is detectable on suckers and saplings and contributes to mortality of these age classes. There are standardized sampling techniques and guidelines for Aspen Stands Sampling should include: 1) Number of stems/ acre by age class 2) Account of stand health including parasites and pathogens 3) Canopy cover by aspen and conifers 4) Quantitative measure of browse by insects and ungulates 5) Measure of rubbing/ biting by elk especially on pole size aspen 6) GPS location data 7) Some assessment of the understory plant community

Aspen Jarbidge, Caudle Creek.

Goose Creek aspen Jarbidge Cherry Cr. stand little little regeneration regeneration

Jarbidge Deer Creek. Jarbidge Low er Elk w allow and W illiam s Basin. brow se. Current use by elk only no livestock.

Need to verify use by ungulate species Browse of Young Aspen Related to Density of Ungulate Pellets Current and Old Ungulate Pellets/acre Elk & Deer Pellets/Acre Browse of Young Aspen Percentage of Young Aspen Browsed 3000 100 90 Ungulate Pellets/Acre 2500 80 70 2000 60 1500 50 40 1000 30 20 500 10 0 0 Copper Basin Aspen WP 586 old #2 Deep Creek Aspen Sept Bucks Creek Aspen Copper Basin Aspen #1 Pine Mnt Aspen Rattlesnake Aspen Mc Donald Aspen new Rocky Gulch Aspen Tennessee Aspen

Number of Pole versus Sucker Age Class Aspens Related to Current Browse on Suckers, Jarbidge 2010 Ratio Pole/Sucker age class % Current Browse 1.20 100% Ratio of Aspen Poles to Aspen Suckers 90% Percentage of Browsed Suckers 1.00 80% 70% 0.80 60% 0.60 50% 40% 0.40 30% 20% 0.20 10% 0.00 0% Caudle Cr Cherry Cr Deer Cr Draw Cr Humm. Lime Cr Lower Upper Raker Short Cr Up Draw Cr Upper T Cr Upper Aspen Aspen Aspen Ridge Sprgs Basin Aspen Williams Cr Aspen Aspen Aspen Aspen Williams Aspen Aspen Basin Aspen Basin Aspen

Illustration: Sequenced Stem Production Current year’s growth = cyg Dormant bud = db Lateral bud = lb Previous year’s growth = pyg Terminal bud = tb Terminal bud scar = tbs Schematic of willow stems showing annual height growth without browsing (a), with browsing (b), and with an alternating pattern of browsing and nonbrowsing (c). Adapted from Keigley and Frisina (1998). In “INCREASED WILLOW HEIGHTS ALONG NORTHERN YELLOWSTONE’S BLACKTAIL DEER CREEK FOLLOWING WOLF REINTRODUCTION”, Beschta and Ripple, 2007. Arrested, Retrogressive, or Uninterrupted Reproduced courtesy of Keigley and Frisina (1998), in “Browsed Plant Method for Young Quaking Released Growth Type Growth Type Aspen”, USDA, 2004.

Often a stand with no or few pole or regeneration age aspen and high ungulate browse will have a very high number of sucker or reproduction age aspen.

Microhistal Analysis of Current Year Elk Pellets, Bruneau River Area Grass Forbs Shrubs Aspen 100% 90% 80% Composition by Graminoid, Forb, Shrub and Aspeni 70% 60% 50% 40% 30% 20% 10% 0% Aspen Bucks Cr. Aspen Copper Basin Aspen McDonald Aspen Rattlesnake Aspen WP 583 MM and MS Rattlesnake

Mountain Mahogany

Mature MM highlined, Severe brow se on no longer produces juvenile MM, this is low er branches. m ost likely 3 0 years old.

Mountain Mahogany by Age Class, Bruneau 2009. Average Stem Density of Mountain Mahogany, by Age Class, 2009 250 Juvenile Immature/ Young Mature Mature Decadent 200 Average Stems/Acre 150 100 50 0 Bridge Gulch MM Merritt Mnt MM Rattlesnake MM Sand Creek MM Telephone Creek MM

Mountain Mahogany Stems per Acre by Age Class Seedling/Juvenile Immature Young Mature Mature Decadent 900 800 700 600 Number of Stems/Acre 500 400 300 200 100 0 Buckhorn Ridge Goat Cr MM MM#1 MM#2 N. Cottonwood MM Raker MM T Cr MM Upper Draw Cr MM MM

Jarbidge 2010, Browse on MM is higher at sites with less understory. Total Understory Plant Cover Related to Use on Mountain Mahogany 60 R² = 0.3827 Average Percentage of Mountain Mahogany 50 40 30 Leader Use 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Percentage Understory Cover

Closed canopy mature mnt. mahogany stand at T Cr. with no regeneration (left) and an open mnt. mahogany stand with regeneration (right). Jarbidge 2010.