Leda - PowerPoint Presentation

Slide1

Leda N. Kobziar School of Forest Resources and Conservation University of Florida

Ecological Effects- short versionChapter IX: Interagency Prescribed Fire TrainingSlide2

Ecological Effects - OutlineObjective: Understand the what and how of fire’s role in Florida’s

ecosystemsFire dependent ecosystems of Florida, their fire regimesFire’s effects on ecosystem components e.g. water, soil, vegetation, fauna

Relationship between timing/season of fire and ecosystem effects

How to manipulate fire regime attributes to encourage specific ecological responsesSlide3

Fire in Florida

Objectives

1) Identify fire’s primary effects on the basic physical ecosystem components of water and soils.

2) Identify fire’s primary effects on floral (plants) and faunal (animal) components of ecosystems.

3) Identify common Florida fire-dependent ecosystems and frequency of fire return intervals that sustain

them (IN YOUR BOOK)

4) Understand the relationship between season or timing of fire applications and certain ecosystem responses.

5) Understand the connection between burn prescription parameters and ecological effects.Slide4

What does fire ecology entail?

Fire history (pyrodendrochronology, reconstructions, sediment and pollen charcoal analyses)Fire regimesFire dependence or adaptations of plants and animals- AUTECOLOGY

Fire effects on water, plants, animals, from individuals to populations, communities, ecosystems, landscapes.

Fire effects on nutrient, energy, and carbon cyclingSlide5

Why is fire ecology important in the south?Slide6

US Wildfires by Region: 2000-2010Slide7

Fire in FloridaSlide8

Fire in Florida

Florida’s

Historical

Fire Regime: May-JuneSlide9

Native Americans burned to stimulate grasses and forage, acorn production, reduce fuels and pests, clear land for agroforestry, increase access, herd game, etc.Practices adopted by European Settlers (c. 1700s to mid 1900s)12,000+ yrs

of Lightning + Anthropogenic Fire UseSlide10

Thousands of yrs of repeated burning ecosystem structure & compositionSelected for fire-resistant or fire-dependent species (e.g. longleaf pine, red cockaded woodpecker) and communitiesResulted in 26 fire dependent and/or

influenced communities in Florida alone (1/3rd of 81 total).Legacy of anthropogenic and lightning fires

Chris EvansSlide11

The Florida Natural Areas Inventory lists 81 communities in Florida: 18 of these are considered FIRE DEPENDENT– will change significantly if any aspect of the fire regime is changed for a given length of time.These ecosystems cover the majority of non-developed land area in Florida. Examples:

Sandhill, Upland Pine Frequent, 1-3 yrsScrub Variable, 5-30 yrs

Dry Prairie Frequent, 1-2 yrs

Mesic

Flatwoods Frequent, 1-4

yrs

Scrubby Flatwoods Variable, 5-15 yrs

Wet Flatwoods Frequent, 3-10 yrs

Glades Marsh approx. 2-5

yrs

Marl Prairie Frequent, 1-6

yrs

Repercussions of long-term burning



FL Fire EcosystemsSlide12

Unsustainable harvesting & fire suppression

 forest

Degradation: ~3% original forest remaining

Lack

of seed sources,

regeneration of fire adapted species

A

ltered

soil fertility, pH,

texture,

mycorrhizae

…

Loss of fire-structure dependent wildlife spp.

Closed communities

with limited

early successional species recruitment

Changes in flammability and fuels structure

Fuel

load build-up



larger, less predicable, higher severity, more costly wildfiresSlide13

In the south, reversing The Legacy of suppression and degradation means using prescribed fire to restore and maintain native ecosystemsSlide14

What’s in the prescribed burner’s “restoration toolbox”? FIRE REGIME ATTRIBUTES Fire frequencySeasonality

Extent of area burned/ landscape heterogeneityType (crown, ground, surface)Intensity

SeveritySynergy, interaction with other disturbances

Includes using fire with mechanical treatments,

silviculture

, CLIMATESlide15

Longleaf pine

Southeastern

US

Fire 1-4 years

Low intensity, understory,

Spring/ summer

Florida Big Scrub (sand pine)

Fire 30+

years,

high intensity, crown,

spring or summer, large areas

Basin swamp

Fire >

5-150

years, small

area, mixed

severity, only

burns during

drought (peaty soils)

Randy Cyr

Frequent fire

Infrequent fire

Examples of Historical FL Fire RegimesSlide16
Slide17

The South burns more than any other region of similar size in the world…but still doesn’t meet fire rotation goalsSlide18

QuizSouthern Region:354 M acres forest pre-settlementHow many acres would have burned historically to maintain a 10-yr average FRI across the forests?200 M acres forest today 8 M burned…how much more should

be burned?Caveat: “forest” includes plantations, which are not subject to the historical FRI…but you get the picture!Slide19

Depth to Water Table (m)

Fire Interval

Pine Flatwoods

High Pine

Sand Pine Scrub

Shrub Wetland

Savanna

Marsh

Bay head

Hydric Hammock

Mesic

Hammock

Xeric Hammock

Slash pine scrub

Rosemary scrub

Low scrub

Oak scrub

Rosemary scrub

Rosemary Bald

Fire regimes correspond to the Distribution of FL native ecosystemsSlide20

Without

fire sand pine scrub will likely succeed to xeric oak/hickory scrub.

Example: sand pine scrubSlide21

Serotinous cones (Pinus clausa

)Open after heating by fire, require bare mineral soil for germination Slide22

Quiz: What fire regime attributes would you “prescribe” to regenerate the stand?Given this knowledge of fire ecology: Sand pine doesn’t burn well unless it’s a drought, or around March-May when resin content is highest and MC is lowestThe cones require high heat; the crowns of the trees must be burnedThe seeds require bare mineral soilYounger trees don’t produce enough viable seeds to regenerate a stand, are killed by fireSlide23

a

a

b

b

b

b

a

a

adequate for

overstory

restocking

Importance of fire severity:

P.

clausa

seedling

recruitment

Senescent

MatureSlide24

Severity and stand age/ frequencySlide25

Example: Reference Condition- savannaSlide26

DirectlyFire FrequencyFire SeasonArea BurnedIndirectlyFire TypeFire IntensityFire Severity

Fire regime attributes manipulated goalsSavanna Restoration

Low density, mature

overstory

(BA < 15

m

2

/ha)

Small regeneration gaps

Grassy understory, diverse herbaceous component

High C sequestration

Low hardwood occupancy

Wildlife habitat function (imperiled species: red cockaded woodpecker, gopher tortoise, skink, etc.)

Wildfire mitigation function: reduce severity by reducing fuel loadsSlide27

Successful Prescribed Fire Use = Applied Fire Ecology to Meet Management ObjectivesSlide28

Where to find information?Southern Fire Exchange: hub for resourceshttp://southernfireexchange.org/index.htmlSlide29

Start with the basics: General Fire Effects on Plant CommunitiesCompetition for moisture, nutrients & light are temporarily reducedSpecies composition and successional stages are alteredEarlier seral stage, but not alwaysStructure of community may changee.g.

susceptibility to blowdownFuel profiles may change fire effectsCertain species may be selectively eliminated or selected for based on their degree of fire adaptationThis changes over the life cycle of a plant/ phenology Slide30

Plant Adaptations to Fire Flower & seed production stimulated (e.g. wiregrass)Seed germination stimulated (seed or soil conditions)

Rapid growth & development (e.g. longleaf pine)Fire-resistant bark, self pruning of ladder fuels (most pines, mature hardwoods)Adventitious buds (gallberry, pond pine)

Root/ tuber/ rhizome sprouting, and storing carbohydrates (oaks, saw palmetto, perennial grasses)

Serotinous

cones (

sand pine)

Flammability (?)Slide31
Slide32

Woody plant mortality: multiple mechanisms, time-dependent

Hiers et al. Final Report: JFSP 01-1-3-11 Slide33

Woody Plant Mortality- CrownsCrown scorch (dead foliage)increases as air temperature increasesmay not kill crowns of longleaf and slash pines Crown mortality affected by:

stand & shrub densityfuel concentrations at the base of treesbud dormancy & heat resistancefoliar moisture contentpresence of flammable compoundsSeason!!! Resistance high when dormant, lower in late summerSlide34

Woody Plant Mortality- stemsStem & cambium mortality affected by:bark thickness & heat resistancestem diameter & degree of heat girdlingheat received during all stages of combustion

Damage to tree stems managed by:controlling fire intensity, flame length, and residence timereducing duff & litter consumption where long unburnedSlide35

Looks Severe…Will everything die?Slide36

Nope! That’s the beauty of fire adaptation.Slide37

Woody Plant Mortality- RootsRoot mortality affected by:depth of lateral and feeding rootsmoisture content of duff/litter and surface soilsduration of fire heatingDamage to roots managed by:

knowing where roots are locatedregulating duff & litter consumption by burning at specified moisture contentsDrought indices are important to considerInfluence duff consumption

Hiers

et al. Final Report:

JFSP

01-1-3-11 Slide38
Slide39

Fire-Caused Plant Mortality- effects of fuel and structureFuel & stand characteristics affect lethal heatingHeat disperses in open stands

High fuel loads increase heat releaseHigh fuel moisture content decreases heatLitter and duff accumulations increase heating at base of stemTherefore, burn prescriptions also affect mortality: fire regime attributes:Frequency: Frequent fires reduce fuel loads

Intensity: Ignition pattern (how so?)Season of burnSlide40

Woody Plant Mortality- Secondary effectsMortality may develop slowly (even over a period of several years)Damage in one part of plant stresses other partsSecondary infection by insects or fungi

Post burn environment matters (drought/rain)

Bark beetle pitch tubesSlide41

Woody Plants: Post-Fire RecoverySprouting is the recovery mechanism in most hardwoods and shrubs:Roots, root crowns, dormant stem buds, rhizomesSurvival related to depth, locationdependent on season and fire severity

most sprouting: low intensity, dormant season burnsleast sprouting:high intensity, growing season fireslow soil moistureHigh organic matter consumptionexceptions when reproductive parts deep in soilSlide42

Managing for Post-Fire Seedling EstablishmentReproduction by seed after a prescribed fire can be managed by:knowing the seed ecology of a speciesBurn prescription

size and/or intensity of burn- seeding species often require bare mineral soil. What does this suggest about desire litter/duff consumption/ severity?season/timing of burn- post burn precipitation is important!Schedule burns to take advantage of seasonal responsesSlide43

SummaryEffects on PlantsPlants vary in adaptations to fire Fire effect is created by interaction of weather, fuel conditions, fire behavior, & site

moisturePost-fire conditions significantly affect recovery & productivityPlant community responses are predictable, if you learn about plant ecologyLandowner should monitor burning conditions and post-fire

responses and make changes to subsequent prescriptions as necessarySlide44

Effects on Animals:General PrinciplesMany Florida species have evolved in a fire environmentMortality levels are generally low (direct effects)Indirect effects on cover and food sources can be substantial but vary across the landscape and diminish with timeSlide45

Animals with limited

mobility (young, old, small animals) are more vulnerable to injury and mortality than animals with high mobility (mature or larger animals, flying species).

Smokey’s great grandson?Slide46

The principle way that fire affects fauna is by affecting HABITATCover is temporarily decreasedMicroclimate is modifiedFood sources

& nutritional quality increaseplant species diversity increasesfoliage of new herbaceous plants and shrub sprouts is more palatable and higher in nutrients (N,P) and crude proteinseed production of many species increases abundance and diversity of insects may increase

prey are more visible for predatorsSlide47

For Wildlife in General, Create Habitat DiversityGrant SteelmanSlide48

Example: WILD TURKEY ROTATION PATTERNMixed burn rotations such as the one above with a three year rotation provide adequate nesting and escape habitat when the adjacent unit has been burned. Mix dormant/growing season burns (Grant

Slide: Grant SteelmanSlide49

Putting it all together: when to burn, how?Slide50

Seasonal Effects: Dormant SeasonIncrease number of stems of many hardwoods and shrubs ***Generally doesn’t kill larger diameter hardwoods (e.g. oaks)Favors bird species that prefer shrubby - hardwood habitatsSlide51

A few months makes a difference: Wiregrass seed production vs. shrubs (gallberry)

May Burn

August

BurnSlide52

Fire season: effects on understory, fire behavior, summer

vs. winter

Saw palmetto: 80% annual growth in summerSlide53
Slide54

10 mo. post burnSlide55

Seasonal Effects: Early SpringDeciduous hardwoods most susceptible to damage

Can be top killed after leafing out, don’t have carbo. Reserves to respondPositive for hardwood controlMay be a negative for mast production for wildlifeMay damage gamebird nests and brood, but food supplies probably not a problem, especially with patchy firesSlide56

Seasonal Effects: Growing SeasonStimulate flowering/seed production of many grasses and forbsincrease number of original plants that flowerincrease number of flowering stems per original plantHigher damage to shrubs and hardwoods

Top-kills larger, more stems than dormant season burnreduces amount of resproutingincreases percentage of individuals completely killedSlide57

Seasonal Effects: Growing Season-2If fire conducted during rainy, humid weather, results may be more patchy than in dry weathera positive for wildlife habitata negative for some other objectives

Small pines may be damaged by intense fire if ambient temperatures are highFavor birds that prefer open woodlands & grasslandsSlide58

Seasonal Effects: FallEvergreen trees (pines) & shrubs (including palmetto & gallberry) most susceptible to damage!!!!Most hardwoods will not be affectedSlide59
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Crown damage, season in southern pinesSlide61

Fire in Florida

How do we manipulate fire to achieve desired

e

cological effects?

Burn Prescription

Parameters.

What will influence fire’s behavior that will result in specific ecological effects?

1) Weather parameters before, during, and after the burn (Air temp., RH, precipitation, wind)

2) Timing of the burn

3) Ignition patterns

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Fire in Florida

Firing Plans/Ignition Patterns

Slow moving fires of all types are hotter at the soil surface, and have more potential to heat and ignite ground (subsurface) fuels 

and affect roots and soil

To minimize the degree of fire

severity,

limit the fire residence

time

3) The pattern of ignition (how the fire

is applied, could be solid line, point

source or a combination) will alter

the intensity of the resultant

fire

 ecological effects

Slide63

SummaryMajor factors that influence ecosystems:Depth to water table Fire frequency, fire regimes

Effects on animals include:Direct Mortality - MINORHabitat changes – can be MAJOR (+)Wildlife, plant diversity and numbers increase with a

mosaic of successional stages created by a variety of fire prescriptions over timePyrodiversity promotes habitat diversity promotes species diversitySlide64

Smokey says, “Burn wisely!”