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