Response of to Wildfire: Rockin’ the Shock Phase

Byron Love Utah State University USDA ARS Pollinating Research Unit

Photo: Mark Rabdau, 2009 Fire as an Ecosystem Process Influences plant & communities Resets succession trajectories

Effects of Fire on Natural Systems Direct mortality due to combustion Indirect loss of shelter and resources Temporal Influences of Fire Acute Phase few hours or days Shock Phase few months to < 1 year Recovery Phase 1 to 10 years

Acute Phase: Ignition, Combustion, Pyrolysis Direct effect through exposure to lethal temperatures Risk factors: Fire dynamics Life stage (adult or immature) Nesting strategy Above-ground = high risk Below-ground = lower risk (Cane & Neff, 2011)

Photo: Mark Rabdau, 2009 Temporal Influences of Fire Acute Phase few hours or days Shock Phase few months to < 1 year Recovery Phase 1 to 10 years

Indirect effects on bees Loss of nesting materials Changes in plant community community recovers rapidly Temporal Influences of Fire Acute Phase few hours or days Shock Phase few months to < 1 year Recovery Phase 1 to 10 years

Indirect effect through removal of nesting, pollen and nectar resources

Effects are dependent on seasonality

Long Butte Fire 21 August, 2010 123,881 hectares (478 sq. miles) Ready-made transects of Helianthus annuus Hypothesis:

Bee density, abundance, and species richness will be lower in the burned habitat compared with adjacent unburned habitat Methods Bee Density Surveys on Helianthus annuus Measure of pollination service 10 surveys in the burn, 4 outside the perimeter (control)

Pan Trapping Provides bee abundance and richness 10 colored bowls per 100 meter transect 4 transects in the burn, 4 outside Traps were open for 4-6 hours

Sampling Over 4 day period, September 3-14, 2010

Min distance to edge = 5 miles

Pan traps Surveys Burn Unburned (n = 10) (n = 4) Bee Density/100 25 + 11 27 + 4 P = 0.68 flowerheads (average + se) Bee Abundance 108 151 (average + se) (27.0 + 10.5) (37.8 + 6.9) P = 0.42 Species Richness 22 25 (average + se) (6.0 + 0.6) (8.6 + 1.1) P = 0.02 Species Intact Burn Agapostemon (Agapostemon) angelicus/texanus 32 77 Long Butte fire bee species list Agapostemon (Agapostemon) femoratus 0 1 Agapostemon (Agapostemon) virescens 10 16 Andrena sp. 0 3 Anthophora (Heliophila) flexipes 1 0 Anthophora (Heliophila) petrophila 1 2 Anthophora (Mystacanthophora) urbana 1 3 Bombus (Pyrobombus) huntii 1 0 Bombus (Separatobombus) griseocollis 3 0 Diadasia enavata 12 12 Dianthidium (Dianthidium) curvatum 26 3 Dianthidium (Dianthidium) pudicum 0 1 Dufourea marginata 0 10 Halictus (Halictus) ligatus 1 0 Halictus (Seladonia) tripartitus 9 4 Lasioglossum (Dialictus) incompletum 13 20 Lasioglossum (Dialictus) sp. 62 53 sp. 1 0 Megachile (Argyropile) parallela 8 1 Megachile (Litomegachile) sp. 2 0 Melissodes sp. 12 8 Melissodes (Callimelissodes) lupina 2 0 Melissodes (Eumelissodes) agilis 13 82 Melissodes (Eumelissodes) bimatris 0 2 Melissodes (Eumelissodes) grindeliae 4 48 Melissodes (Eumelissodes) microsticta 12 1 Perdita sp. 13 9 Sphecodes sp. 1 0 Svastra (Epimelissodes) obliqua 2 0 Triepeolus sp. 1 10 Xeromelecta (Melectomorpha) californica 0 1 Species Intact Burn Agapostemon (Agapostemon) angelicus/texanus 32 77 Long Butte fire bee species list Agapostemon (Agapostemon) femoratus 0 1 Agapostemon (Agapostemon) virescens 10 16 Andrena sp. 0 3 Anthophora (Heliophila) flexipes 1 0 Agapostemon & Melissodes Anthophora (Heliophila) petrophila 1 2 Anthophora (Mystacanthophora) urbana 1 3 Deep ground nesters (>>5cm) Bombus (Pyrobombus) huntii 1 0 Bombus (Separatobombus) griseocollis 3 0 Diadasia enavata 12 12 Dianthidium (Dianthidium) curvatum 26 3 Dianthidium (Dianthidium) pudicum 0 1 Dufourea marginata 0 10 Halictus (Halictus) ligatus 1 0 Halictus (Seladonia) tripartitus 9 4 Lasioglossum (Dialictus) incompletum 13 20 Lasioglossum (Dialictus) sp. 62 53 Megachile sp. 1 0 Megachile (Argyropile) parallela 8 1 Megachile (Litomegachile) sp. 2 0 Melissodes sp. 12 8 Melissodes (Callimelissodes) lupina 2 0 Melissodes (Eumelissodes) agilis 13 82 Melissodes (Eumelissodes) bimatris 0 2 Melissodes (Eumelissodes) grindeliae 4 48 Melissodes (Eumelissodes) microsticta 12 1 Perdita sp. 13 9 Sphecodes sp. 1 0 Svastra (Epimelissodes) obliqua 2 0 Triepeolus sp. 1 10 Xeromelecta (Melectomorpha) californica 0 1 Species Intact Burn Agapostemon (Agapostemon) angelicus/texanus 32 77 Agapostemon (Agapostemon) femoratus 0 1 Agapostemon (Agapostemon) virescens 10 16 Andrena sp. 0 3 Anthophora (Heliophila) flexipes 1 0 Anthophora (Heliophila) petrophila 1 2 Anthophora (Mystacanthophora) urbana 1 3 Bombus (Pyrobombus) huntii 1 0 Bombus (Separatobombus) griseocollis 3 0 Diadasia enavata 12 12 Dianthidium (Dianthidium) curvatum 26 3 Dianthidium Dianthidium (Dianthidium) pudicum 0 1 Dufourea marginata 0 10 Surface nesters Halictus (Halictus) ligatus 1 0 Halictus (Seladonia) tripartitus 9 4 Lasioglossum (Dialictus) incompletum 13 20 Lasioglossum (Dialictus) sp. 62 53 Megachile sp. 1 0 Megachile (Argyropile) parallela 8 1 •Megachile parallela Megachile (Litomegachile) sp. 2 0 Shallow ground nester (2cm) Melissodes sp. 12 8 Melissodes (Callimelissodes) lupina 2 0 Melissodes (Eumelissodes) agilis 13 82 Melissodes (Eumelissodes) bimatris 0 2 Melissodes (Eumelissodes) grindeliae 4 48 Melissodes (Eumelissodes) microsticta 12 1 Perdita sp. 13 9 Sphecodes sp. 1 0 Svastra (Epimelissodes) obliqua 2 0 Triepeolus sp. 1 10 Xeromelecta (Melectomorpha) californica 0 1 Conclusions Adult bees survived the Acute Phase of wildfire

Bee abundance during Shock Phase may be related to presence of unburned floral resources

Bee richness decreased during the Shock Phase

Ground nesting species were favored over surface and shallow nesting species Response of Perennial Forbs to Fire Surviving bees require suitable bloom in the 1st post fire year

Literature focuses on the response of populations and communities

Response of individuals is not well known Let’s burn stuff and see what happens!

Treatment Variables Response Variables Plant characteristics Productivity Heating regimes Reproduction Seasonality

Comments and Suggestions PLEASE! [email protected] Acknowledgements: Jim Cane, USDA ARS, Logan, Utah Nancy Shaw, USDA USFS, Boise, Idaho Seth Naftziger, USDA ARS, Logan, Utah