2012 Woodlands, Sagebrush & Fuels Treatments Field Day

May 30, 2012, Northeastern California

We had a great day at the SageSTEP Blue Mountain study site and other US Forest Service treatment areas. Thanks to everyone who participated! Photos and notes from the tour are provided below or by clicking on these links:

SageSTEP Blue Mountain Study Site, Stop 1
SageSTEP Blue Mountain Study Site, Stop 2
US Forest Service Study Area

SageSTEP Blue Mountain Study Site, Stop 1

Dr. Rick Miller, Plant Community Ecologist, Oregon State University

Background

Click here for the Blue Mountain site description. This is a western juniper area where prescribed burning and cut-and-drop treatments were implemented in fall 2007.

With this prescribed fire there was high tree mortality.  Girdling helped reach that mortality goal.  Exotics are not a problem here.  Cheatgrass is present, but not dominant.  The study sites are on a gradient from the dry end of juniper to higher elevation cool mountain systems and exhibit one of the three soil temperature regimes in the Great Basin: Mesic (below 4,000 ft.), Frigid (from 4,000 to 6,000 ft.), and Cryic (above 6,000 ft.).  You have to worry about cheatgrass on the mesic sites, but this site has frigid soils, so cheatgrass is not so much a concern.  In mesic sites the limiting factor is water.  This site exhibits a xeric (> 12”) precipitation regime (rather than an aridic regime of < 12” precip.).  You can feel better about burning on frigid or cryic soils. 

Images of the prescribed burn area five years after treatment.

We see a consistent pattern throughout the sites:

Year Post-Burn

Grass Response

1

decrease

2

equal to preburn and control

3

increase

 

Cutting treatment: 5 years later

 

Cut plots

Uncut plots

Erodibility

1/2 hour of rain before run-off, clear

immedidate run-off with sediment

Tree growth

trees still growing

Important points:

Wildlife Study

Steve Hanser, Wildlife Biologist, US Geological Survey

Invertebrate Research

Dr. Jim McIver, Ecologist, Oregon State University

All invertebrate species studied at Roberts site are native, so despite the fact that the site has been degraded somewhat by invasion of exotic plant species, the invertebrate is still fairly healthy.
A general principal of management is that no matter what you do, treatments (including no treatment) will result in declines for some species and increases for others.

We studied invertebrates in three main groups:

  1. Ants: because they are functionally important in these desert ecosystems. Ants are scavengers and predators, serve as prey for vertebrates, disperse and kill seeds, and dominate the invertebrate biomass.
  2. Spiders: because they are very good indicator species, and are often used to determine whether management treatments cause effects that are unintended.
  3. Butterflies: because butterflies are one group of invertebrates that many people care about  (they are ‘charismatic mesofauna’), and their larvae are tied to specific native host plants. Thus changes in their abundance or diversity may reflect changes in the floristic base.

In general, 2-4 years after treatment, effects on these three groups of fauna were subtle and transient.

Highlights:

  1. Ants: fauna relatively unchanged after treatment – ants nest underground, and so most of the individuals within colonies are not exposed to treatments when they occur. They are also social, and so effects on individuals are relatively unimportant. Ants are also perennial, and many species have resources (seed stores) that can help them survive bad periods of time.
  2. Spiders: declines in several species in the short term.  We saw significant declines with fire, but after 2-3 years many species bounce back. Spiders are solitary and active when treatments occur, and so are vulnerable to treatments like fire in the short term. But spiders also disperse very well by ballooning, and so tend to recolonize treated sites after a few years.
  3. Butterflies: Butterflies tend to prefer treated sites, especially if treatment results in improved nectar resources. One potential mechanism: remove woody biomass and you get an increase in ground water availability; increase ground water availability and you can get an increase in floral resource; increase floral resource and you can get an increase in butterflies, because they prize nectar.

The only possible unintended consequence we observed is a potential effect of the herbicide spike on butterflies.

  1. Spike (used to decrease foliar cover of sagebrush by 50%) – we saw a decline in overall butterfly abundance, but there was a bigger effect on the Whites.  Probably due to the decrease in foliar cover. We expect they will rebound in time, but we must measure through time to determine this.

Questions/Discussion

Climate Change: As the climate warms we expect to see the trees move up in elevation.  We’re not sure what the precipitation is going to do.  Lower elevations might get too dry for cheatgrass.  We don’t know what the birds will do.

Some of the phase III sites have been burned by hand because there is not enough understory to carry the fire.

Stansbury was the hottest prescribed fire in the SageSTEP network and it decreased the severity of the wildfire that came through after.

SageSTEP Blue Mountain Study Site, Stop 2

Dr. Rick Miller, Plant Community Ecologist, Oregon State University

There is no cheatgrass at this site because it is on a north slope with good understory.  The site has loamy soils >2 ft deep.  The abundance of Idaho fescue means it’s a good indicator of a cool, wet site. Elevation, aspect, soils, and understory will all have an effect on the outcome of a grazing disturbance. Sandberg's bluegrass increases with grazing disturbance. First we found cheatgrass under the downed, juniper-dense canopy, but then squirreltail came in and replaced it. Forbs on these type of sagebrush sites typically account for 5-10% of a site. It's your grasses that are important. That's true for butterflies too. They need perennial bunch grasses.

Images of the cut-and-drop area five years after treatment.

 

Overall Treatment Effect on Native Understory

 

Burn

Cut

Year 1

decrease

increase

Year 2

increase

increase

Year 3

increase

no change

Exotics

increase

small increase

First we found cheatgrass under the downed, juniper-dense canopy, but then squirreltail came in and replaced it.

Forbs only ever make up 5-10% of a site.  It’s your grasses that are important.

That’s true for butterflies too.  They need perennial bunch grasses.

Questions/Discussion

This site has a deferred rotation grazing – every other year.

Cost of treatments = $70/acre for mechanical removal with pile burn.  Burning piles in the winter is great.  With piling, the burning is more controlled so your window for burning is larger.  It’s more functional.  Turning soil is most disturbing.  Sage grew out of piles in some cases.  Some grew native forbs, some cheat.

For ranchers, fire is cheaper unless you’re in the WUI.

US Forest Service Study Area

Chrissy Pearson, Rangeland Management Specialist, Modoc National Forest 

At this site juniper was removed by hand from 700 acres in 2011. These photos show the site one growing season after treatment (May 30, 2012).

Comment on carbon budgets:

At this site, trees were removed from 1,000 acres using a stroker/delimber and skidder.

Eventually the Forest Service will remove juniper from 1,750 acres here using mechanical treatments. 

Rancher Comment: Up until 1914 this area got much more moisture.  There was a 1,000 acre lake until the reclamation project.  Many people here grew dryland crops until then.  The sagebrush stands now were hayfields then.  During World War I they used this area for artillery horses. 

We’ve seen one sage grouse on Harvey Butte.

Mountain sage, mosaic of low sage, and wet seep areas make a good combo for grouse.  Grouse need short grass.  They won’t forage in tall grass.  This is why grazing is so important for sage grouse (we’re talking about grazing in meadow areas where the grass will grow back).  Before grazing, deer and fire kept grasses short.