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Seminars. “Plant Talk” – Thurs April 8 12:00 PM in FA 214. Eric Petersen: “ Using remote sensing to estimate the distribution of cheatgrass in Nevada.”

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Presentation Transcript
slide1

Seminars

  • “Plant Talk” – Thurs April 8 12:00 PM in FA 214. Eric Petersen: “Using remote sensing to estimate the distribution of cheatgrass in Nevada.”
  • EECB Colloquium OSN 102 at 4:00 PM Thursday April 8. Graham Hickling, Michigan State. "Emerging Disease in Wildlife Populations: Bovine Tuberculosis as a Case Study”
slide2

Reading

  • D’Antonio, C., and Vitousek, P. 1992. Biological invasions by exotic grasses, the grass fire cycle, and global change. Ann. Rev. Ecol. Syst. 23: 63-87.
  • FYI: Pellant, M. 1996. Cheatgrass: the invader that won the West. BLM Interior Columbia Basin Ecosystem Management Project report: http://www.icbemp.gov/science/pellant.pdf
slide3

Outline

  • Extent of cheatgrass invasion
  • Distribution and history of invasion
  • Why is cheatgrass a good invader?
  • What are the problems?
  • How can we reverse the process?
  • “Integrating weed control and restoration” project
  • Discussion
slide4

Extent of cheatgrass invasion in Great Basin

  • Bromus tectorum dominates 3 million acres
  • Another 14 million acresare invaded
  • 60 million acres are vulnerable to invasion
slide5

Oregon

Idaho

Nevada

Utah

Cheatgrass dominated

Cheatgrass invading

Cheatgrass susceptible

slide6

Origin and history

  • Bromus tectorum originally from SW Asia and middle east
  • Introduced as contaminant in wheat seed
  • First records in southern BC, eastern Washington
  • Spread quickly, but didn’t become dominant. Current distribution reached by around 1930.
  • Why could it invade and become dominant?
slide7

Why could invasion occur?

  • Opportunistic
  • Prolific seeder
  • Plastic life history (winter or spring annual)
  • Good competitor
  • Somewhat grazing tolerant
  • Changes fire regime
  • “pre-adapted” to cold desert conditions
  • Suppression of native community by grazing?
slide8

What is the problem?

  • Loss of perennial species and wildlife habitat
  • Increase in fire frequency (damaging and costly)
  • Hard seeds injure stock
  • Good fodder for short period only
slide9

Problem

  • Loss of native rangelands
slide10

Why?

  • Invasive weeds (cheatgrass)
slide11

Why?

  • Fires
slide21

Natives

Restoration

Cheatgrass

How?

  • A transition stage
    • State and transition ecological model
slide22

Natives

Transition

Cheatgrass

How?

  • A transition stage
    • State and transition ecological model

Natives

Restoration

Restoration

Cheatgrass

slide23

Rangeland restoration project

  • First – identify promising commercially available species and varieties for restoration planting (Experiment 1)
  • Second – investigate competitive ability of cheatgrass and planted native community. Close the open niche for cheatgrass (Experiment 2)
  • Third – demonstrate management options on larger scale (Experiment 3)
slide24

Collaborative project:

Oregon

Idaho

Nevada

Utah

Cheatgrass dominated

Cheatgrass invading

Cheatgrass susceptible

  • Bob Nowak UNR NRES
  • Bob Blank USDA ARS
  • Chris Call Utah State University
  • Jeanne Chambers USFS RMRL
  • Paul Doescher Oregon State University
  • Hudson Glimp UNR CABNR
  • Tom Jones USDA ARS
  • Nancy Markee UNR CABNR
  • Dan Ogle NRCS Plant Materials Center
  • Mike Pellant BLM Idaho State Office
  • Barry Perryman UNR CABNR
  • Dave Pyke USGS FRESC
  • Allen Rasmussen Utah State University
  • Gene Schupp Utah State University
  • John Tanaka Oregon State University
  • Robin Tausch USFS RMRL
slide25

Experiment 1: agronomic trials of drill-seeded species

  • Thurber’s needlegrass – Orchard
  • Bluebunch wheatgrass – Goldar, Anatone, P-5
  • Thickspike wheatgrass – Critana, Bannock
  • Snake River wheatgrass – Secar, KBJ
  • Squirreltail – Sand Hollow, 2nd accession
  • Indian ricegrass – Nezpar, Rimrock, Rimrock HG
  • Basin wildrye – Magnar, Trailhead, NV MOPX
  • Bluegrass – Sherman, High Plains, Mountain Home
  • Crested wheatgrass – Vavilov, CD-2
  • Wheat sterile hybrids (3 varieties)
  • Plants of local interest – Shadscale, winterfat
  • Globemallow
slide26

Izzenhood Ranch Study Site

8-10“ precipitation zone

slide27

Eden Valley Study Site

10-12“ precipitation zone

slide28

Experiment 1 procedure

  • Drill-seeded into 10’ by 20’ trial plots, 6 blocks at each study site. Planted November 2003.
  • 3 blocks sprayed with post-emergent herbicide, 3 not sprayed
  • Growth, survival, biomass of planted species will be monitored.
  • Results so far – differences among emergence rate of different accessions;
slide29

390\'

50\'

Herbicide application

50\'

50\'

50\'

410\'

Individual study plots with varietal seeding randomly assigned. Each plot has 10 rows with 1‘ row spacing.

20\'

10\'

70\'

10\'

10\'

120\'

slide30

Experiment 2

  • Seed monocultures of accessions, native species mix (6 species with range of growth forms) + cheatgrass
  • Add labile carbon (sucrose) to ½ plots to sequester N
  • Monitor emergence, growth and survival of both planted species and cheatgrass
  • Preliminary results – carbon addition appears to reduce emergence of both natives and cheatgrass, but cheatgrass suppressed more (3X)
slide31

Experiment 2

Reduce soil nitrogen

  • Cheatgrass inhibited by low soil nitrogen,

Natives are tolerant of low nitrogen

  • Soil amendments to tie up nitrogen
  • Mix of natives to deplete resources

sagebrush, yarrow, globe mallow, bluegrass

squirreltail, bluebunch wheatgrass

slide32

300\'

Herbicide application

Sugar application

No sugar

15 m

350\'

15 m

15 m

Individual study plots with seeding treatments randomly assigned

15 m

1.5 m

2.5 m

15.5 m

2 m

2 m

2 m

2 m

23 m

slide33

Experiment 3

  • Demonstration of potential management techniques on larger scale (3 ha)
  • To be implemented Autumn 2004
  • Location – Biddell Flats (25 miles north of Reno)
slide34

How?

  • A transition stage
  • Reduce soil nitrogen
  • Large-scale restoration trials
    • Transition community vs. Native mix
    • Restoration treatments targeted at:
        • reduce cheatgrass seedbank
        • reduce soil N
  • Treatments:
    • Control – no treatment
    • Burn-seed-burn-seed: to reduce cheatgrass seedbank.
    • Transitional community. Sterile hybrid.
    • Grazing to reduce cheatgrass seed set
    • Herbicide (‘gold standard’ for control)
    • Burning and grazing combination
slide35

200 m

200 m

100 m

5,250\'

Mixed

species

Best

accessions

Control

Burn-Seed-Burn-Seed

Herbicide

4,140\'

100 m

100 m

Grazing

Burn-Graze

15 m spacing

slide36

Benefits

  • Restore land health
  • Invasive species control
    • Reduce cheatgrass
    • Reduce secondary weeds (knapweed,
        • starthistle, skeletonweed)
    • Restoration also reduces invasibility

Anderson & Inouye (2001)

slide37

My research

  • What makes rangeland invasible in the first place?
  • Common knowledge – shrub steppe is resistant to invasion
  • unless overgrazed.
  • BUT – cheatgrass is “pre-adapted” to cold desert conditions
  • - there are few native annual species (vacant niche?)
  • - there is a large amount of empty space even in healthy
  • community
  • - resources are variable; could pulsing of resources allow
  • invasion?
  • Greenhouse studies (individual plant performance, mesocosms,
  • field test)
slide38

Questions for discussion

  • What principles of ecology are we applying?
  • How does understanding ecology of the system help
  • the design and interpretation of the experiment?
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