Wyoming Big Sagebrush Sites Fire/Land Treatment Study Overview

Transcription

1 Wyoming Big Sagebrush Sites Fire/Land Treatment Study Overview J. Swanson, S. Swanson, P. Murphy K. McAdoo, B. Schultz University of Nevada; UNR Cooperative Extension Ranches

2 Elko BLM

3 Elko BLM

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5 Implications NEPA, Planning, Policies Disturbance Response Group Concept Validation Treatment/Site Suitability Criteria Monitoring/Research Priorities Science Conflicts/Gaps

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7 Drivers: Event Area Selection Time Period - Range of aspects, elevations, slope positions, etc - Geographic Dispersion - Wildfire/land treatment adjacency

8 Drivers: Sampling Area Selection - Homogeneity - Range of ecological states/phases - No unique noise (vehicle parks, etc.) - Absence of supplemental treatments (incl seeding) - Apparent barriers to fire spread - Ease of physical access

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14 Cryptogams

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17 Control Mow

18 Cover Shift SynMon surrogate for Response Shift value = Mow value Control value

19 Positive Shift Mow Site Exotic Forb Cover 5 Control Site Exotic Forb Cover 2 Exotic Forb Cover Shift + 3

20 Negative Shift Fire Site Sagebrush Cover 5 Control Site Sagebrush Cover 2 Sagebrush Cover Shift - 15

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27 Questions

28 Fire Stuff

29 Investigators Event State Study Extent Sites Sampled Comparative Analysis? Bates and others (29) P. Burn OR 65 ha 5 Grazing regimes Beck and others (29) P. Burn ID 1 Fire 18 Temporal changes Bollinger and Perryman (28) Wildfire NV 1 Valley 28 Ecological sites Chambers and others (27) P. Burn NV 2 ha 6 Pre-burn veg removal levels Davies and others (27) P. Burn OR 6 ha 6 None Davies and others (28) P. Burn OR 3 ha 6 Cheatgrass seeded/unseeded Davies and others (28a) P. Burn OR 3 ha 6 None Davies and others (29b) P. Burn OR 5 ha 6 Microsite location Davies and others (29a) P. Burn OR 195 ha 3 Grazing regimes Davies and Sheley (211) P. Burn OR 1 ha 6 Chem/Burn Treatments Diamond and others (212) P. Burn NV 11 ha 3 Graze/Burn Treatments Fisher and others (1996) P. Burn ID 58 ha 12 None Hassan and West (1986) Wildfire UT 8 ha 8 None Hess and Beck (212) P.Burn WY 32, km 2 19 Ustic vs. aridic soils Hilty and others (24) Wildfire ID 3 locales 3 None Peek and others (1979) P. Burn ID 86 km 2 2 None Perryman and others (22) P. Burn CO 6 burn areas 26 None Rhodes and others (21) P.Burn OR 2 ha 5 None Wambolt and Payne (1986) P.Burn MT 6 ha 4 Chem/mech/burn treatments Wambolt and others (21) P.Burn MT Two counties 13 None Watts and Wambolt (1996) P.Burn MT 6 ha 4 Chem/mech/burn treatments West and Hassan (1985) Wildfire UT 8 ha 7 None West and Yorks (22) Wildfire UT 8 ha 7 Grazing regimes SageSTEP P. Burn 6 GB-Wide

30 Variable Wyo Sage Sites Cover Response to Fire Greater in Burned Area Greater in Control/Pre-Burn Area No Major Difference Bare soil 2,6,8,9,1,11,12,13,23 5 1, 7, 16, 18, 2 Litter 16 2, 6, 7, 1, 11, 12, 13 1, 8, 17, 18, 23 Rock 16, 23 Cryptogams 1, 6, 8, 9, 23 7 Live Vascular Vegetation Sagebrush 1,2,4,8,9,15,16,17,19,2,21,23 22 Rabbitbrush 1, 2, 8, 9 4 Total Shrub/Half-Shrub 2, 18, 23, 24, 25 Native Forbs 1, 4, 19 Exotic Forbs 1, 8, 19 Annual Forbs 1, 8, 1, 16, 25 4, 6, 11, 17, 24 Perennial Forbs 9, ,7,1,14,16,2,24,25 All Forbs 2,18 Native Grass 6 1, 4, 17 All Perennial Grass 9, 11, 19, 24 6, 2,23 1,4,7,8,1,15,16,17,21 Cheatgrass/Annual Grass 3, 9, 16, 23, 24 5, 6, 8, 11 4, 7, 1, 25 All Grass 18 2 Annual Herbaceous 5 Perennial Herbaceous 5 All Herbaceous 1, 4, 5, 18, 19 6, 7 All Vegetation 17 4, 23 18, 24

31 Basal Cover Bare Soil Litter Rock Cryptogam Live Vegetation Foliar Cover Sagebrush Dead Sagebrush Other Shrub Native Forb Exotic Forb Native Graminoid Perennial Graminoid Cheatgrass Total Native Herbaceous Total Exotic Herbaceous Sagebrush Canopy Volume Variable SynMon Data Range of Cover Shifts

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40 Fire event sites (red = prescribed burn)

41 Counties Central Nevada Esmeralda, Eureka, Lander, Nye Northwest Nevada and Northeast California Humboldt, Modoc, Pershing, Washoe Northeast Nevada Age of Fire (Years) Elko Elevation Ranges (m) Prominent Burned Site Vegetation Native Graminoids-Native Forbs Native Graminoids-Exotic Forbs Native Graminoids-Native/Exotic Forbs Native Graminoids-Cheatgrass Native Graminoids-Granite Gilia Native Graminoids-Rabbitbrush Native Forbs-Native Graminoids Native Forbs-Cheatgrass Exotic Forbs-Native Graminoids Exotic Forbs-Rabbitbrush Cheatgrass-Native Graminoids Cheatgrass-Native Forbs Cheatgrass-Native Graminoids/Forbs Cheatgrass-Exotic Forbs Cheatgrass-Rabbitbrush Cheatgrass-Shadscale Rabbitbrush-Native Forbs sites sites sites Total Sites Sampled

42 Are there any significant cover value differences between the control and adjacent burn sites?

43 All Burned Sites (n = 51) Variable Mean Shift SD SE t P Basal Cover Bare Soil Litter Rock Cryptogam <.1 Live Vegetation <.1 Foliar Cover Sagebrush <.1 Dead Sagebrush <.1 Other Shrub <.1 Native Forb Exotic Forb <.1 Native Graminoid Introduced Graminoid Perennial Graminoid Cheatgrass <.1 Total Native Herbaceous Total Exotic Herbaceous <.1 Sagebrush Plant Canopy Volume <.1

44 Prescribed Burns (n = 6) Component Mean Shift SD SE t P Basal Cover Bare Soil Litter Rock Cryptogam Live Vegetation Foliar Cover Sagebrush <.1 Dead Sagebrush Other Shrub Native Forb Exotic Forb Native Graminoid Introduced Graminoid No data Perennial Graminoid Cheatgrass Total Native Herbaceous Total Exotic Herbaceous Sagebrush Plant Canopy Volume

45 How soon after fire did any significant shifts become apparent? How long did they last?

46 Cover Variable Cover Response Observation Period -6 Years 6-1 Years 1-2 Years > 2 Years Bare soil C: 4 N: 5 B: 6,8,9,1,11,12,2,23 N: 18, 2 N: 2 Litter C: 5,6,9,1,11,12 N: 7,8 N: 18 C: 2 B: 16 Rock Cryptogams C: 1,6,7,8,23 N: 5 C: 16 Live Vascular Veg Sagebrush C: 1,3,4,7,8,13,17,19,2,21,23 C: 14,15,18,2,21 Dead Sagebrush Rabbitbrush N: 1,3,19 B: 7,8 B: 2 Other shrubs Total Shrub C: 17,23,24,25. C: 24,25 C: 2,16,24,25 Native Perennial Forbs N: 1,3,5,6,9,13,19,2 C:23,24,25 B: 1 C: 24,25 N: 2 Exotic Forbs B: 7,8,19 N: 23 B: 16 Annual Forbs B: 1,7,8,9,24,25 N: 3,6,1,17 B: 24,25 B: 24,25 Total Forb N: 18 C: 2 Native Graminoids N: 3,17,19 C: 23 N: 14 B: 15,18 N: 16,2 Introduced Grasses Perennial Grasses Cheatgrass/Medusahd N: 1,5,7,9,2 C: 6,23,24,25 B: 8,1 N:1,3,5,9 C: 4,6,1 B: 7,8,23,24,25 N: 2,25 B: 24 C: 24 B:25 C: 2,16,2,21 N: 22 C: 21 N: 16,24,25 B:2 N: 2,2,25 B:24 B: 16,24, 25 All Peren Herbaceous B: 4 All Annual Herbaceous B: 4 Total Herbaceous B: 1,3,4,19 N: 5,6 Total Vegetation C: 3 B: 23,24 N: 25 N: 18 C: 24,25 N: 24, 25

47 Fire Ages 4 yrs (n = 14) 5-6 yrs (n = 14) 7-8 yrs (n = 8) 9-1 yrs (n = 9) >1 yrs (n = 6)

48 Bare soil Litter Rock Cryptogams Live veg Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Native grasses Introduced grasses All perennial grasses Cheatgrass Time since burn Time since burn Time since burn

49 Do any of the shifts vary by region (NW Nevada/NE California, NE Nevada, Central Nevada)? Their MLRA's? Their ecological sites?

50 Major Post-Fire Response Differences? Cover Variable Soil Type Ecological Site Microsite (Interspace vs. Coppice) Fire Area Region/MLRA Bare soil No: 2 Yes: 4 Litter No: 2 Yes: 4 Rock Cryptogams No: 2 Live Vascular Veg Sagebrush No: 3 Yes: 5 Dead Sagebrush Rabbitbrush Yes: 5 Other shrubs Yes: 5 Total Shrub Yes: 4,5 Native forbs No: 2 Exotic forbs Annual forbs No: 2 Total Forbs Yes: 4, 5 Native Graminoids No: 2 Introduced Grasses Perennial Grass Yes: 3 No: 2 Yes: 4, 5 Cheatgrass/Annual Grass Yes: 1 No: 2 Yes: 4 Perennial Herbaceous Total Herbaceous No: 2 Yes: 4, 5 Total Vegetation Yes: 4

51 Basal cover Variable Central Nevada n = 13 Mean Absolute Cover Shift (%) and SE NE Nevada n = 16 NW Nevada/NE CA n= 22 ANOVA Results F p Bare soil Litter Rock Cryptogams Live Vascular Veg Foliar cover Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Native Graminoids Introduced Grasses Perennial Graminoids Cheatgrass

52 Major Land Resource Area ( MLRA ) Geographic area within which land use, hydrology, topography, landscape conditions, soils, climate and other natural resource characteristics are similar.

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54 Mean Cover Shift (%) and SE ANOVA Results Variable Malheur n = 1 S. NV Basin & Rng n = 2 Humboldt n=14 Great Salt Lake n = 8 Owyhee n = 17 F P Basal Cover Bare soil Litter Rock Cryptogams Live Vascular Veg Foliar Cover Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Native Graminoids Perennial Graminoids Cheatgrass

55 Mean Absolute Cover Shift (%) and SE ANOVA Results Variable Loamy 8-1 n = 31 Loamy 1-14 n = 4 Droughty Loam 8-1 n = 3 Other n = 7 Unknown n = 6 F P Basal Cover Bare soil Litter Rock Cryptogams Live Vascular Veg Foliar Cover Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Native Graminoids Cheatgrass

56 Which of the control site and burn site variables are significantly correlated?

57 Control vs event Control Sites bare soil litter rock cryptogams live veg bare soil litter Event Sites rock cryptogams live veg

58 Control Sites bare soil litter rock cryptogams live veg Forbs native exotic Event Sites native Grasses introduced cheatgrass

59 sagebrush dead sagebrush Control Sites sagebrush canopy volume other shrubs sagebrush Event Sites dead sagebrush sagebrush canopy volume other shrubs

60 sagebrush Control Sites dead sagebrush sagebrush canopy volume other shrubs native.267 Forbs exotic Event Sites native Grasses introduced cheatgrass.43

61 Forbs Control Sites Grasses native exotic native introduced cheatgrass sagebrush Event Sites dead sagebrush sagebrush canopy volume other shrubs

62 Forbs Control Sites Grasses native exotic native introduced cheatgrass native.665 Forbs.745 exotic Event Sites native Grasses introduced.753 cheatgrass

63 Does control site topography, aspect, or elevation predict significant burn site responses?

64 Shifts with elevation (n = 51) Bare soil Litter Rock Cryptogams Live veg Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Native grasses All perennial grasses Introduced grasses no stats Cheatgrass Elevation (ft) Elevation (ft) Elevation (ft)

65 Shifts with slope position Bare soil Litter Rock Cryptogams Live veg Slope position Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Slope position Native grasses All perennial grasses Introduced grasses no stats Cheatgrass Position: 1= bottom 2= lower 3= middle 4= upper 5= top Slope position

66 One-way ANOVAs: Does aspect (N, E, S, W) predict shifts? Response DF SS MS F P Bare soil Litter Rock Cryptogams Live veg Sagebrush Dead sagebrush Other shrubs Native forbs Exotic forbs Native grass Native + Intr gr Introduced grass Cheatgrass

67 Interactions Peter Murphy

68 Are there any significant correlations between control site sagebrush parameters, and burn site native and exotic herbaceous foliar or relative cover shifts?

69 Sagebrush Parameters 1. Sagebrush foliar cover 2. Sagebrush relative cover 3. Mean sagebrush plant volume (ft 3) = π * (½ max. plant width inches) * (½ plant width inches at 9 to max) * (height of canopy top height of canopy bottom inches) / Sagebrush production index = Sagebrush Vol * Sagebrush FC

70 Does sagebrush cover pre-fire correlate with the dominance* of native herbs (forbs + grasses) post-fire? *Dominance = Natives/introduced cover minus exotics cover Control Sagebrush Cover Foliar cover Relative cover Burned Site Herbaceous Dominance Foliar cover (%) Relative cover (%) Natives Natives Nat + Intro Nat + Intro

71 Does sagebrush volume/pi pre-fire correlate with the dominance of native herbs (forbs + grasses) post-fire? *Dominance = Natives/introduced cover minus exotics cover Burned Site Herbaceous Dominance Foliar cover (%) Natives Nat + Intro Control sagebrush Plant Volume Production Index Relative cover (%) Natives Nat + Intro Log(Ft 3 + 1) Log(% * Ft 3 + 1)

72 Does control site sagebrush cover interact with geographic, temporal or other factors to predict shifts?

73 ANCOVA: NATIVE SHIFT = REGION + SAGEBRUSH (TfmAbsCvr) + INTERACTION Region: P =.879, Ctrl Sagebrush: P =.473, Interaction: P =.715

74 MULT. REGRESSION: NATIVE SHIFT = TimeSinceFire + SAGEBRUSH (TfmAbsCvr) + INTERACTION TimeSinceFire: P =.47, Ctrl Sagebrush: P =.4, Interaction: P =.16

75 More sagebrush cover pre-fire means greater native herbaceous shifts post-fire Region: Does not interact with sagebrush to affect this relationship MLRA: Malheur HP: Interacts - does not favor or even hinders the above relationships. Other MLRA s: Do interact. Ecosite: Ecosite does not interact with sagebrush to affect this relationship

76 Are there any significant correlations between control site herbaceous foliar or relative cover, and burn site herbaceous foliar or relative cover shifts?

77 The cover of cheatgrass pre-fire (at control sites) is strongly & negatively correlated with the degree of native herbaceous dominance post-fire; the cover of native grass at control sites is at best weakly & positively correlated with the degree of native herbaceous dominance post-fire. Native herbaceous dominance post-fire r =.187 P =.188 ρ =.295 P =.35 Native herbs dominate Exotic herbs dominate r = P <.1 ρ = P <.1 * Control Foliar Cvr Native Grass Control Foliar Cvr Cheatgrass *points above gray line are sites that were native dominated post-fire, while those below the gray line were exotic dominated post-fire

78 The cover of cheatgrass pre-fire (at control sites) is negatively correlated with degree of shift towards a native herbaceous dominated community; the cover of native grass at control sites is not consistently predictive of the degree of shift towards native herb dominance. Net shift in native herbaceous dominance from pre- to post-fire r = P =.26 ρ = -.72 P =.617 Net shift towards natives Net shift towards exotics r = P =.315 ρ = P =.2 * Control Abs Cvr Native Grass Control Abs Cvr Cheatgrass *points above gray line are sites that were more native dominated post-fire, while those below the gray line were more exotic dominated post-fire

79 What site characteristics pre-fire best predict native herbaceous dominance post-fire?

80 Technique used: multiple regression with predictor variables added in a stepwise fashion: at each step: predictor added that best-improves fit 3 fit criteria compared: AIC c, AdjR 2, SBC (Schwarz Bayesian info. Criterion) at each step: predictors added in earlier steps re-checked & removed if their removal improves model fit

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82 Control site cheatgrass, litter, and exotic forb cover; and the time since fire are the best predictors of native herbaceous dominance after fire. Cheatgrass explains the largest proportion of variation in the data, followed by litter and elapsed time (since fire).

83 Control site cover of native grass, rock, and bare soil (in unburned sites), and the time since fire and site elevation are the best predictors of the native herbaceous shifts after fire. Native grass cover explains the most variation in the response, followed by rock and time since fire. Elevation is the fourth most important predictor, but its importance declines as additional predictors are added to the model.

84 Native grass cover & time since fire interact strongly in their effect on the shift in native herbaceous dominance pre- to post-fire. Sites with both large native grass cover and more time since fire are less likely to be native dominated. But sites with high native grass cover & less elapsed time, or lower native grass cover & more elapsed time, are more likely to be native dominated.

85 9. Is there a control site graminoid cover value below which burn site exotics domination occurs? Above which graminoid and/or native perennial forb domination occurs?

86 1.Are there any significant correlations between control site exotic forb and cheatgrass cover, and burn site exotic forb and/or cheatgrass relative cover shifts? 11. Are any of the above responses or relationships comparable to those observed in Nevada mechanical, biological, or chemical event areas? Or, do they significantly differ?