Patricia N. Manley, USFS Pacific Southwest Research Station Angela - - PowerPoint PPT Presentation

Patricia N. Manley, USFS Pacific Southwest Research Station Angela M. White, USFS Pacific Southwest Research Station Gina L. Tarbill, USFS Pacific Southwest Research Station

• T. Will Richardson, Tahoe Institute for Natural Science

 Burned 1,255 hectares  Burn severity varied due to

wind, slope, fuel load, and fire- fighting efforts

 On Wildland-Urban Interface  Post-fire harvest largely

limited to WUI

• Modifies forest structure and composition
• Creates, alters, and destroys wildlife habitat
• Alters arthropod

populations

• Creates snags and woody

debris

Photo credit: USDA Forest Service

 How do bird and small mammal communities

differ by burn severity?

 How does time since fire, urbanization, and post-

fire harvest affect this response?

How do species richness and abundance

• f 36 avian and 11 mammalian species

differ?

0.2 0.4 0.6 0.8 1 1.2 1.4 None Low Moderate High Mean abundance Burn severity Lazuli Bunting Olive-sided Flycatcher Western Bluebird Mountain Bluebird Black-backed Woodpecker House Wren Hairy Woodpecker 1 2 3 4 5 6 7 8 9 10 None Low Moderate High Mean abundance Burn severity Long-eared Chipmunk Deer Mouse

 Six species of birds and eight species of small mammals

increased in abundance after first year

 Several species had highest abundance in second year  No significant difference between burned and unburned

by year three

0.5 1 1.5 2 2.5 3 3.5 4 4.5 none low moderate high none low moderate high none low moderate high Year 1 Year 2 Year 3 Douglas Squirrel Golden-mantled Ground Squirrel

 Harvest was limited  No species had lower

abundance in treated sites

 Five bird and one small

mammal species had higher abundance in treated sites

 None were fire-specialists

 Several fire-adapted species had slower “recovery” in

urban sites

 Four species “recovered” more quickly in urban areas

• 0.3
• 0.2
• 0.1

0.1 0.2 0.3 0.4 0.5 0.6 0.7 Hairy Woodpecker House Wren Mountain Bluebird Pine Siskin White-crowned Sparrow Yellow-rumped Warbler Evening Grosbeak Black-headed Grosbeak Change from first to third year Urban Wild

 Majority of birds and small mammals

responded positively or neutrally to increasing burn severity

 Fire specialists did not exhibit a

decreasing year effect

 Most species increased over time  Species that rely on live trees for foraging

• r nesting sites likely to decline with

increasing burn severity

5 10 15 20 25 30 2 4 6 8 10 12 14 16 18 20 Year 1 Year 2 Year 3 Mean species richness Mean total abundance Time since fire Total abundance Species richness 5 10 15 20 25 13 13.5 14 14.5 15 15.5 16 16.5 17

None Low Moderate High

Mean species richness Mean total abundance Burn severity Total abundance Species richness 1 2 3 4 5 6 7 8 9 none low moderate high none low moderate high none low moderate high Year 1 Year 2 Year 3 Mean species richness Burn severity

Birds Small mammals

2 4 6 8 10 5 10 15 20 25 30 none low moderate high Species richness Total abundance Total abundance Species richness

 Species richness of birds

was highest in sites that burned at high severity

 Species richness of small

mammals was highest in low burned sites

 Richness of small

mammals equal in year three for high and unburned

 Harvest in urban areas may

have less of an impact on fire- dependent species

 Burned urban and wildland

sites do not support similar communities

 Severely burned sites provide

habitat for many species

 Burned areas support a wide

variety of birds and small mammals especially at larger time and spatial scales

 Southern Nevada Public Lands Management Act  California Tahoe Conservancy  Tahoe Institute for Natural Science  Lake Tahoe Basin Management Unit, USFS  Region 5 Ecology Group, USFS  University of Montana

Photo credits: Naturepicsonline