The effects of the 2002 Hayman Fire on the ponderosa pine/bunch

grass ecosystem

Nick KelleyBlake Schnebly

•www.nifc.gov/gallery/

Hypotheses

• Null: Crown replacement fires have the same effect on ponderosa/bunch grass ecosystems as low intensity fires.

• Alternative: Crown replacement fires alter the soil, vegetation, and canopy cover more than low intensity fires.

•www.artbypritika.com/ shakti/fire.jpg

Background• Ponderosa/Bunchgrass • Historically fire-dependent -forest & tree structure • “Encourage” low intensity fire -leaf sloughing• Reduces competition• Fire suppression has altered this regime

– Ladder Fuels– Buildup– Parasites

•www.artbypritika.com/ shakti/fire.jpg •www.pacificresearch.org/pub/sab/enviro/03_enviroindex/22_forests.html

Catastrophic Fires • Causes Stand Replacement

– Humans

– Drought

– Severe parasitism

• Effects Stand Replacement– Seed bank/Regenerators

– Erosion

– Type of vegetation/Weeds/Colonizers

• Effects Low Intensity Burns– Nutrient Flush

– Clears forest litter

– Prevents stand replacement fires•www.sofia.usgs.gov/.../ images/fire-forest.jpg

Three Zones• Control- has not burned

recently and shows no fire “damage”

• Low intensity- burned ground vegetation, the canopy is alive and intact occasional torching

• Crown Replacement- full burn including the tops of trees and organics in the soil

Survey Criteria

• Soil temperature– Assumed temperature is not sun/shade dependent

• Soil moisture– Percentage by comparing wet/dry weight

• Canopy Cover– Percentage of footprint

• Species Richness– The total number of different ground plant species

• Species Area/Percent Coverage– The area a species of ground vegetation covers

Materials • Compass• Soil Corer• Thermometer• Inclinometer• GPS• Digital Camera• Tape Measure • Flags• Vegetation Key• 1/2 meter Grid• Plastic Bags• Pens

Methods • Random Plot Generator and Compass

– Unbiased site location

• 6 Plots along a 25m line– Improve survey quality

• 1/2 Meter Grid– Identify species and estimate coverage percent

• Soil Temperature• Soil Sample

– Core to 14cm mark

• Canopy Cover– Estimated and averaged

• Location and Elevation – GPS

• Slope Aspect and Angle– Compass– Inclinometer

•www.wortley.cc/grotto/ survey_equipment.jpeg

Expected Results of Alternative Hypothesis

• The three zones– species richness/area – Canopy coverage %– Soil moisture– Soil temperature

• Relationship– Moisture/temperature– Temperature/Canopy

Error Bars show Mean +/ - 1.0 SD

Bars show Means

Control Low Int. Stand Rep.

Type of burn

2.5

5.0

7.5

10.0

12.5

15.0

17.5

20.0

Avera

ge C

an

op

y C

over

]

]

]

Canopy Cover Vs. Type of Burn

•www.magicalgiraffe.com/new/ survey/introduction.ht

Error Bars show Mean +/ - 1.0 SD

Bars show Means

Control Low Int. Stand Rep.

Type of burn

0.00

2.50

5.00

7.50

10.00

12.50

15.00

17.50

Avera

ge S

oil

Tem

pera

ture

]

]

]

Average Soil Temperature

•www.thegrillstoreandmore.com/image/products/big-pics/12inch-thermometer.jpg

Soil Moisture Vs. Type of Burn

Error Bars show Mean +/ - 1.0 SD

Bars show Means

Control Low Int. Stand Rep.

Type of burn

0

5

10

15

So

il M

ois

ture

(%

)

]

]

]

•This is a stand replacement zone

Species Richness Vs. Burn Type

0

5

10

15

20

25

30

1

Burn Type

Nu

mb

er

of

Sp

eci

es

Standard ReplacementLow IntensityControl

Control Area Low Intensity Stand ReplacementThree Types of Burn areas

Percentage of Plant Species per Burn Area

Percent Coverage per Species per Zone

Dot/Lines show Means

10.00 12.50 15.00 17.50 20.00

Average Soil Temperature

0.0

10.0

20.0

Ave

rag

e C

ano

py

Co

ver

Average Canopy Cover = 10.79 + -0.25 * av._tempR-Square = 0.02

Linear Regression

Canopy Cover vs. Average Soil Temperature

T-Test- .632

A correlation is shown, however, it is not statistically accurate

T-Test= .121

Soil Moisture per Temperature

Results: Conclusion

• Supported– Canopy Cover– Soil Moisture– Species Richness– Species Area– Soil Temperature vs.

Soil Moisture– Soil Temperature vs.

Canopy Cover (statistical error)

• Discredited– Soil Temperature

– Soil Temperature vs. Canopy Cover (statistical error)

Possible Sources of Error

• Thermometers • Elevation• Time of Day • Date of Survey• Weather • Personal Bias• Nonreplicable

• Missing samples• Small sample quantity• Slope aspect• Slope angle• Protocol• Sampling error• Equipment limitations

Possible Improvements/Alterations

• Shorter sample window

• Similar weather

• Maintaining possession of equipment

• Technological improvements of protocol

• Increase sample size

• Incorporate other data

Conclusions• Fire maintains the stage of succession in

ponderosa/bunch grass ecosystems• Significant differences between zones• Stand replacement fire appears to alter the

ecosystem’s condition more than historical low intensity fire

• Stand replacement fire lowers the soil moisture, increases soil temperature, decreases canopy cover, reduces vegetation, and possibly limits re-vegetation