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Plan for Today (2/25/11). Weekly meteorologist Derek Jones Lecture: Fire effects on wildlife, intro. Guest lecture, Louise Venne- fire effects on wading birds in the Everglades Lab: Burn at ACMF?. Wildlife and Fire . Fire Ecology and Management, 2011 An introduction
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Plan for Today (2/25/11) • Weekly meteorologist Derek Jones • Lecture: • Fire effects on wildlife, intro. • Guest lecture, Louise Venne- fire effects on wading birds in the Everglades • Lab: • Burn at ACMF?
Wildlife and Fire Fire Ecology and Management, 2011 An introduction Adapted from Deborah Kennard
Ecological Effects of FireBasic Premises • All ecosystems change over time • Fire is neither innately good nor bad; it is just an agent of change • Human perception of whether it is good or bad depends on resource objectives • Do people think fire is good for wildlife?
Fire’s Effects on Wildlife Most animal species respond predictably to the passage of fire, although the responses vary among species. Some flee, seek refuge, or rescue young. Other species are attracted to burning areas (forage during fires or feed on charcoal and ash after fires).
Effects on Animals:General Principles • Many North American species have evolved in fire environments • Mortality levels are generally low • Effects on cover and food sources • Substantial and generally positive • Vary across the landscape • Effects on individuals may be substantially different than effects on populations
Are all fires created equal? • Fire regime characteristics dictate fire effects on wildlife • What are the fire regime components? • Type • Season • Area burned/ extent • Intensity • Severity • Frequency • Synergy
Effects of Animals on fires:General Principles • Fires may be: • Lower intensity or less frequent • reduced by grazing • Increased intensity or severity • by insect damage • More heterogeneous • E.g. pig damage to fuel continuity Terry Clason
Direct Effects on Animals • Vertebrates • Mortality: mobility & underground nests decrease this risk • Related to size of fire and rate of spread • Loss of nesting sites and young, but... • Cavity nesters and insect foragers love dead trees • Immediate increase in food source for predators • Invertebrates • Mortality high in burn area for life stages in litter or on plants • Rapid invasion by some species may follow burn • Species composition changes to early successional fauna
Indirect Effects on Animals • Habitat: components? • Shelter is temporarily decreased • Microclimate is modified
Indirect Effects on Animals • Food sources & nutritional quality increase • plant species diversity increases • foliage of new herbaceous plants and shrub sprouts is more palatable and higher in nutrients (N,P) and crude protein • seed production of many species increases • abundance and diversity of insects may increase
Indirect Effects on Animals • Habitat modifications - examples • Birds • quail and turkey prefer more open conditions • RCW - regular low intensity fires kill hardwoods • scrub jays – periodic fires recreate scrub habitat • Fire bird
Indirect Effects on Animals • Habitat modifications - examples • Large mammals • deer benefit from flush of new growth for browse • Small mammals • increased seed production important for food
Direct and indirect effects- soil microorganisms • Populations decrease significantly, especially in upper horizons and duff • Long term effects? • After fire: • Black surfaces increase temperatures • Run-off, leaching of nutrients if post-fire rain • Competition decreases for populations that can respond quickly
Seasonal Effects: Dormant Season • Increase number of stems of many hardwoods, shrubs & grass • Generally don’t kill large diameter hardwoods (e.g. oaks) • Favor bird species that prefer shrubby - hardwood habitats
Seasonal Effects: Early Spring • Deciduous hardwoods most susceptible to damage • a positive for hardwood control • a negative for mast production for wildlife • Can damage gamebird nests and brood, but food supplies probably not a problem, especially with patchy fires
Seasonal Effects: Growing Season • If fire conducted during rainy, humid weather, results may be more patchy than in dry weather • a positive for wildlife habitat • a negative for some other objectives • Flowering may be stimulated, but small pines may be damaged by intense fire • Favors birds that prefer open woodlands & grasslands
Effects on AnimalsEffects of prescribed burns • Few problems if timed to avoid nesting of birds with ground nests • Increase edge effect & browse • Little impact on fish unless streamside vegetation is burned, or erosion occurs
Example: Yellowstone fires of 1988 • The stand-replacing & mixed-severity fires of 1988 in the Greater Yellowstone Area, (mostly lodgepole pine-dominated forest), provided opportunities to study animal behavior during burns (1.2 M acres’ worth!) • Studies focused on large mammals, including bison, elk, bear, moose, and deer. Photo by JeffHenry, courtesy of National Park Service. Bison foraging and resting near burning area, Yellowstone National Park.
Scientists observed NO large mammals fleeing the fires, and most appeared “indifferent” even to crowning fires • Bison, elk, and other ungulates grazed and rested within sight of flames, often 100 m or less from burning trees • “Throughout the summer, animals continued their casual grazing patterns, moving to new locations and for the most part staying ahead of the fire” (firefighter on the scene) Photo by Jim Peaco, courtesy of National Park Service. Bison grazing in area converted by stand-replacing fire from shrub-dominated to forb- and grass-dominated cover.
Yellowstone fires, 1998, cont. • Direct fire mortality: • Surveys found that 345 dead elk (of an estimated 40,000-50,000), 36 deer, 12 moose, 6 black bears, and 9 bison died in greater Yellowstone as a direct result of the fires • Delayed mortality: • Elk mortality was high (up to 4%) in the winter of 1988 to 1989 due to drought in the summer of 1988 and forage loss on burned winter range • Fire-killed elk became a large source of carcasses for scavengers: grizzly bears, black bears, coyotes, bald eagles, golden eagles, etc. • The increased availability of carcasses benefited grizzly bear populations because drought had reduced other food sources • Increased production of forb foliage and tuberous roots also benefited grizzly bears
Summary:Wildlife • Effects on animals include: • Direct: Mortality • Indirect: Habitat changes • Wildlife diversity and numbers increase with a mosaic of successional stages created by a variety of fire prescriptions over time • Desired management effects may be one to several years post-fire (e.g. Florida panther) • Best overall effects by: • varying seasons and intervals of fires • burning in small units • increasing patchiness of burns • Monitoring & adaptive management
Fire Effects on Water • Effects depend on: • fire intensity • exposure of mineral soil • soil texture • slope • rate of revegetation • timing and amount of post-fire precipitation • fire suppression & rehabilitation activities • riparian zones/BMPs
Fire Effects on Water • Hydrologic processes may be modified: • Decreases: • Rainfall interception • Infiltration • Loss of om => soil structure collapses & bulk density increases • Soil porosity decreases • Raindrop impacts compact soil and seal surface pores • Ash & charcoal residues clog soil pores • Evapotranspiration
Fire Effects on Water • Hydrologic processes may be modified: • Increases: • snow accumulation and rate of melting • soil water storage (making runoff & streamflow more responsive to subsequent precipitation) • overland flow/runoff • surface erosion (& even mass movement) • sedimentation • downstream flow
Burned hillslope with high consumption of litter and organic matter resulting from the Buffalo Creek Fire which burned 4,690 hectaresin May 1996 in the mountains southwest of Denver, Colorado.Photo by John A. Moody
After the Cerro Grande Fire near Los Alamos, NM, channels draining burned areas have zones of erosion & deposition. The peeled bark indicates the highest level of water and debris during a flash flood. The view is downstream and the blue backpack is about 1 meter tall. Photo by John A. Moody
Fire Effects on Water • Water quality may temporarily change: • Increases: • sediments – soil particles & organic detritus • turbidity • nutrients – especially N, C, & bicarbonates of Ca, Mg & K • water temperature • Decreases: • aquatic habitat • depends on size of fire • little evidence of long term habitat deterioration • Usually within natural range of variation and/or short-lived effects
Fire Control Effects on Water • Fire retardants • N & P into water • Some toxicity to fish • Fire lines • Connect water bodies • Create channels
Effects on Water - Summary • Cumulative effects may include: • changes in stream channel morphology • organic matter food sources for aquatic fauna • amount & timing of peak flows • …… • Properly planned prescribed burn will generally not adversely affect either quality or quantity of ground or surface water in Florida