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

Basing Elk Population Limits

• n 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

Historical Elk Distribution Current Elk Distribution Nevada

McCullough, 1969

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?

Goal

1.

No reduction in AUMs, no direct competition with livestock

2.

Healthy Aspen stands

3.

Healthy riparian areas

4.

No competition with Mule deer Monitoring m ethod

1.

Pellet counts, utilization and cover by desired species.

2.

Stand structure data, pellet counts, utilization and microhistal analysis.

3.

Pellet counts, use on willows and key species.

4.

Pellet counts, utilization of 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%. No signs of elk use here. WT-04 Private riparian land 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

• nly.

Average Use of Graminoids at Riparian Sites, 2006

83.90 90.00 0.00 13.50 10 20 30 40 50 60 70 80 90 100

SM-05 FALL 06 SM-17 FALL 06 SM-06 ( Rip) FALL 06* WT-04 SUMMER 06* Site and Season Monitored Percentage of Key Graminoids Utilized

Bruneau River 2003

Deep Creek Riparian little elk use. Sand Creek little use on gram inoids and regeneration

• f 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

1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 Cattle No Cattle Cattle Cattle No Cattle Bristol Springs Mud Springs Row land Taylor Creek Tennessee Creek

Percent Foliar Cover from Grasses and Forbs at Mesic

• r Moist Meadow Sites

Bruneau River Elk Monitoring 2009

Deep Creek early spring trailing by elk Highest use on w hite w yethia

Jarbidge 2010

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

Jarbidge 2010

Caudle Creek w illow brow se by elk Cherry Creek w illow 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 Cattle Cattle Cattle Cattle 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

Percent Utilization on Bluebunch Wheatgrass, Goose Creek BLM 2006

1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0

Winter Use by Elk at Upland Sites, Bruneau River 2009

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.

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

Jarbidge Deer Creek. Elk w allow and brow se. Jarbidge Low er W illiam s Basin. Current use by elk

• nly no livestock.

Need to verify use by ungulate species

Browse of Young Aspen Related to Density of Ungulate Pellets Current and Old

500 1000 1500 2000 2500 3000

Bucks Creek Aspen Copper Basin Aspen #1 Copper Basin Aspen WP 586 old #2 Deep Creek Aspen Sept Mc Donald Aspen new Pine Mnt Aspen Rattlesnake Aspen Rocky Gulch Aspen Tennessee Aspen

Ungulate Pellets/Acre 10 20 30 40 50 60 70 80 90 100 Percentage of Young Aspen Browsed Ungulate Pellets/acre Elk & Deer Pellets/Acre Browse of Young Aspen

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0.00 0.20 0.40 0.60 0.80 1.00 1.20

Caudle Cr Aspen Cherry Cr Aspen Deer Cr Aspen Draw Cr Ridge Aspen Humm. Sprgs Aspen Lime Cr Basin Aspen Lower Williams Basin Aspen Upper Raker Cr Aspen Short Cr Aspen Up Draw Cr Aspen Upper T Cr Aspen Upper Williams Basin Aspen

Percentage of Browsed Suckers Ratio of Aspen Poles to Aspen Suckers

Number of Pole versus Sucker Age Class Aspens Related to Current Browse on Suckers, Jarbidge 2010

Ratio Pole/Sucker age class % Current Browse

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

Uninterrupted Growth Type Arrested, Retrogressive, or Released Growth Type

Reproduced courtesy of Keigley and Frisina (1998), in “Browsed Plant Method for Young Quaking Aspen”, USDA, 2004.

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.

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

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Aspen Bucks Cr. Aspen Copper Basin Aspen McDonald Aspen Rattlesnake Aspen WP 583 MM and MS Rattlesnake Composition by Graminoid, Forb, Shrub and Aspeni

Grass Forbs Shrubs Aspen

Mountain Mahogany

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

• ld.

Mountain Mahogany by Age Class, Bruneau 2009.

50 100 150 200 250

Bridge Gulch MM Merritt Mnt MM Rattlesnake MM Sand Creek MM Telephone Creek MM Average Stems/Acre

Average Stem Density of Mountain Mahogany, by Age Class, 2009

Juvenile Immature/ Young Mature Mature Decadent

Mountain Mahogany Stems per Acre by Age Class

100 200 300 400 500 600 700 800 900 Buckhorn Ridge MM Goat Cr MM MM#1 MM#2

• N. Cottonwood MM

Raker MM T Cr MM Upper Draw Cr MM Number of Stems/Acre Seedling/Juvenile Immature Young Mature Mature Decadent

Jarbidge 2010, Browse on MM is higher at sites with less understory.

R² = 0.3827 10 20 30 40 50 60 10 20 30 40 50 60 70 80 90 100 Average Percentage of Mountain Mahogany Leader Use Percentage Understory Cover

Total Understory Plant Cover Related to Use on Mountain Mahogany

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

East Ridge Fire burned 54,500 acres of USFS land in 2008. In 2007 the Murphy Fire Complex burned 595,699 acres, 436,402 acres

• f BLM land in Idaho and Nevada, and

91,185 acres of Forest Service in Nevada.

Need to incorporate other impacts, livestock grazing, fire, roads etc.

Average Density of Aspen per Acre, by Age Class

360 472 225 270 315 5969 674 2428 4721 1248 5621 540 944 674 4688 719 1574 225 899 360 585 719 236 225 180 315 337 495 315 585 2113 225 270 101 764 315 135 1124 4114

1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 15000

Bucks Creek Aspen Copper Basin WP 586 Copper Basin #3 Copper Basin #1 Pine Mnt. Rattlesnake Tennesse Mnt. Deep Creek Rocky Gulch

Average Stems/Acre Sprout Sucker/Seedling Pole/Sapling Mature Decadent

Effect of fire on aspen stands

Number of Live and Dead Stems/ Acre Burned Sagebush-bunchgrass Sites, Bruneau River 2009

1000 2000 3000 4000 5000 6000 Hot Sprg Butte US Rocky Gulch US #1 Rocky Gulch US #2 Taylor Pocket US Wickiup US Stems/acre

Dead Live

Effects of Fire on Sagebrush, Bruneau River 2009.

Take home message from vegetation monitoring in other areas of Nevada

 Elk are not competing with livestock in wet meadows

and riparian areas.

 Elk use on upland grasses is so dispersed it is often

difficult to measure.

 Elk have affected aspen regeneration, however stand

structure data indicates past livestock use impaired regeneration prior to the presence of elk.

 Mountain mahogany sites are preferred elk habitat

and there may be impacts from elk.

We all care about this land, we all care for this land. May we manage it for future generations.