revegetation strategies for brush-pile burn sites
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Comparing revegetation methodologies for brush pile burn sites Scott Gardner Mark Simmons Steve Windhager
Transcript of revegetation strategies for brush-pile burn sites
Comparing revegetationmethodologies for brush pile burn
sites
Scott GardnerMark Simmons
Steve Windhager
Initial Assumptions
• The process of burning brush creates a scar thatseldom recovers to pre-existing conditions.
• The heat from the burn damages the seed bankand soil microbial community, preventingrevegetation.
• This void is often filled with undesirable, and/ornon-native vegetation.
Research Questions
• Does the addition of non-sterilized soilaffect the rate of recovery?
• Does the addition of seed affect the rate ofrecovery?
Hypotheses
• The addition of local non-sterilized soil willincrease the rate of recovery
• The addition of seed will increase the rateof recovery
C.L. Browning Ranch
Site 1 – Seed Addition May 2004
Site 2 – Seed Addition May 2004
Site 5 – Seed Addition May 2004
Site 8 – Soil Addition May 2004
Site 9 – Soil Addition May 2004
Site 6 – No Treatment May 2004
2King Ranch Bluestem222Halls Panicum
111Parralenna222Prairie coneflower
111Rescue grass111Hairy Grama
111BedstrawCurly MesquiteEvolvusPersimmonGreen LillySkeleton PlantFalse Nightshade
212621262126Croton235235235cockle burr
Geranium212212212Sida33Indiangrass222little bluestem33333switchgrass566656665666green sprangletop222222221Canadian wildrye
buffalograssblue grama
444434441sideoats grama222purple three awn
big bluestemGrasses
324324324prairie verbena333333333333black-eyed Susan123123123Clasping coneflower
pink evening primrose444444443333horsemint333233323332Texas bluebonnet
212212212Texas Yellow Star555555555555standing cypress233223322332Maximillian sunflower4423Indian blanket333333333333Engleman daisy333333333333Illinois bundle flower
334334334scrambled eggs323323323plains coreopsis
American basketflower333233323332partridge pea
Flowers333333331111LITTER114111413141BARE432143214321Quad
Sept 23 - 2004July 20thMay 25-28SITE NO. 1-seed + soil
Browning Ranch Burn Pile Research Vegetation Survey
May
Cover (%
)
0
100
200
300
400F=43.5; p < 0.0001
a
b b
July
F=25.8; p < 0.001
a
b
b
September
F=24.5; p < 0.001
a
b
b
Cumulative canopy
No TreatmentSOIL
SEED
No Treatment
Cumulative Canopy
SOILSEED
No TreatmentSOIL
SEED
MAY JULY SEPTEMBER
Conclusions• The addition of unburned soil made little impact
on revegetation indicating that degradation ofthe soil may not be as significant as previouslythought.
• The data showed that successful revegetation iscontingent on seed addition, suggesting that theburn-pile process destroys much of the seedbank as well as adult plants.
• Burn-scars are therefore primarily the result oflocal "seed limitation" rather than an impairmentto the soil infrastructure or microbial community
2004 Treatment No Treatment
2007Treatment No Treatment
Site 1 – Seed Addition July 2007
SITE 3 – No Treatment2004 2007
Site 1 – Seed Addition July 2007
Site 1 – Seed Addition July 2007
Site 2 – Seed Addition July 2007
Site 5 – Seed Addition July 2007
Site 7 – No Treatment July 2007
Site 6 – No Treatment July 2007
Site 3 – No Treatment July 2007
Top 10 Speciesthat worked for us in Blanco County
1 Green sprangletop Leptochloa dubia2 Canadian wildrye Elymus canadensis3 Sideoats grama Bouteloua curtipendula4 Standing cypress Ipomopsis rubra5 Scrambled eggs Corydalis curvisiliqua6 Horsemint Monarda citriodora7 Plains coreopsis Coreopsis tinctoria8 Texas bluebonnet Lupinus texensis9 Prairie verbena Verbena bipinnatifida10 Maximillian sunflower Helianthus maximiliani
2004
Top 10 Speciesthat worked for us in Blanco County
1 Green sprangletop Leptochloa dubia2 Canadian wildrye Elymus canadensis3 Sideoats grama Bouteloua curtipendula4 Little bluestem Schizachyrium scoparium5 Yellow indiangrass Sorghastrum nutans6 Indian blanket Gaillardia pulchella7 Horsemint Monarda citriodora8 Plains coreopsis Coreopsis tinctoria9 Partridge pea Chamaecrista fasciculata10 Maximillian sunflower Helianthus maximiliani
2007
Management recommendations
• Burn during times of high soil moisture
• Locate piles in areas of high productivity
• Keep the piles under 10-feet tall
• Disc all sites after the burn
• Seed all sites two weeks after discing
• Differ grazing and mowing until little bluestem isestablished
Take-home message• Failure to reseed burn sites…
– Increases the chance for undesirable and/or non-native species to establish themselves, which oftenresults in large-scale and long-term problems
– Increases soil erosion during run-off events
– Misses the opportunity to create desirable seedislands
• So seed those burn sites!
Scott Gardner
830-868-2222
