Fire intensity and forb traits
influence survival and bloom the
year after burning
Byron Love
PhD Candidate with Jim Cane
Utah State University
Logan, Utah
Bees Survive Fire
Adults continue nesting
Immatures emerge next year
Post fire bloom needed to
retain bee fauna
Post fire flush of wildflowers
Fact or fiction?
Literature relevant to firesurviving bees is sparse
- population & community
response
- richness, abundance &
cover measures
- grasses do no provide
usable pollen & nectar
Vegetation recovery from a
surviving bee’s perspective:
Must focus on the first year
post-fire in order to retain
bee fauna
Study Requirements:
-First year post-fire
-Forb-centric (bee plants)
-Correct age (mature)
-Good health (bloom &
phenology)
Perennial forbs important
for Great Basin bees
Eriogonum umbellatum,
Sulphur buckwheat
Penstemon cyaneus,
Blue penstemon
Astragalus filipes,
Basalt milkvetch
Species
Growth Form
Bee
Fauna
Fire
Tolerance
Astragalus
fillipes
Forb/herb
Generalist
Medium
Dalea ornata
Forb/herb
Generalist
Unknown
Eriogonum
umbellatum
Low-growing
Woody
Meh
Low
Lomatium
dissectum
Forb/herb;
Taproot
Specialist
High
Penstemon
cyaneus
Subshrub;
Forb/herb
Generalist
Specialist
Unknown
Sphaeralcea
grossulariifolia
Rhizomatous;
Deep woody
taproot
Specialist
Medium
Dalea ornata,
Western prairie clover
Lomatium dissectum,
Fernleaf biscuitroot
Sphaeralcea grossulariifolia,
Globe mallow
Photo Credit
Clint Shock
Study Design Option #1
(Natural Setting)
Study Design Option #1
(Natural Setting)
Pros
Cons
-Serious adrenaline rush
-Kinda dangerous
-Probably illegal
-No control of:
-Fire intensity
-Soil type/nutrients
-Water availability
-Age Class
-Weed/Pest Pressure
Study Design Option #2
(Agricultural Setting)
Malheur Experiment
Station
-Still kinda dangerous
-Control of:
-Fire intensity
-Soil type/nutrients
-Water availability
-Age Class
-Weed/Pest Pressure
The Art of
Artificial Burns
Wright, Bunting & Neuenschwander,
1976. Effect of Fire on Honey Mesquite
DeBano et al., 1979. Soil
Heating in Chaparral Fires
700
Surface Temps
Temperature (°C)
600
500
400
300
200
100
0
Minutes
15:00
14:00
13:00
12:00
129 + 15
11:00
629 + 53
0
10:00
102 + 23
20
09:00
500 + 78
40
08:00
66 + 6
07:00
353 + 31
60
06:00
57 + 4
80
05:00
Very High
241 + 60
100
04:00
High
49 + 4
03:00
Medium
132 + 37
-2 cm Temps
120
02:00
Low
-2 cm
00:00
Very Low
7.5 psi,
24 sec
7.5 psi,
50 sec
15 psi,
65 sec
15 psi,
175 sec
15 psi,
240 sec
Surface
140
Temperature (°C)
Burn
Prescription
Treatment
01:00
Temp + sd
Burn Treatments
- 6 Perennial forb species
- 6 Burn treatments (control to scorch)
- 4 Replicates
- 14 to 72 plants per replicate
(2 to 15 plants per trial)
- 144 Trials
- August, 2012 (fire season)
Post Burn Data Collection,
Spring & Summer, 2013
Species
Mortality
Inflorescence
Production
Bloom Production and
Timing
Astragalus
fillipes
X
X
Bloom Presence / Absence;
Pod Qty (bloom surrogate)
Dalea ornata
X
X
Bloom Phenology;
Inflorecscence length (bloom
surrogate)
Eriogonum
umbellatum
X
X
-
Lomatium
dissectum
X
X
-
Penstemon
cyaneus
X
X
-
Sphaeralcea
grossulariifolia
X
-
-
70
Fire Hardy Forbs
60
% Mortality
50
40
ASFI
30
DAOR
LODI
20
10
0
Control Very Low
100
90
Low
Medium
Burn Treatment
High
Very High
Fire Susceptable Forbs
80
% Mortality
70
60
50
ERUM
40
PECY
30
SPGR
20
10
0
Control Very Low
Low
Medium
Burn Treatment
High
Very High
Effect of Fire Severity
on Bloom
Astragalus filipes
100
% in bloom
80
60
40
20
0
Inflorescences
12
Penstemon cyaneus
9
6
*
3
0
120
Dalea ornata
Inflorescences
100
80
60
40
20
0
*
*
Results Summary
Fire
Tolerant
Inflorescence
Reduction
Reliable
Bloom
Bloom
Suppression
Phenology
Shift
Astragalus
fillipes
Yes
No
Yes
No
-
Dalea ornata
Yes
No
Yes
Low Severity
Fires
No
Eriogonum
umbellatum
No
Yes
No
-
-
Lomatium
dissectum
Yes
No
Yes
No
-
Penstemon
cyaneus
No
Yes
No
-
-
Medium
-
-
-
-
Species
Sphaeralcea
grossulariifolia
Conclusions
Reseeding choices in fire prone habitats
(e.g., E. umbellatum vs. A. filipes )
Bee fauna persistence likely on firetolerant species (offers buffer for
planting of slow-growing species)
Better interpretation of origin of bigger
plants in 2-5 year old burns (survivors,
not recruits)
What are the effects of repeated burning
on mortality and bloom suppression?
Field Examples
Acknowledgements:
Jim Cane, USDA ARS Bee Lab
USFS & BLM
Clint Shock, Malheur Experiment Station
Scott Jensen, Provo Shrub Lab
and of course...
Nancy Shaw