Plant and Animal Adaptations to Fire

What is Evolution??

All changes that have transformed life on Earth from its earliest

beginnings to the diversity that characterizes it today.

Darwin's main ideas from "The Origin of Species"

1. Natural selection is differential success in reproduction

2. Natural selection occurs through an interaction between the environment and the variability inherent among the individual organisms making up a population

3. The product of natural selection is the adaptation of populations of organisms to their environment

How does natural

selection work?

Populations Evolve, Natural

Selection Occurs at the Level of Organisms

Three factors that influence rates of evolutionary

adaptation1) Generation time

2) Rates of reproduction (K vs. r selected species)

3) Strength of selection pressure (frequency/severity of disturbance)

Resistance-directly surviving fire

Resilience-top-killing but re-sprouts (oaks, aspens); annual (cheatgrass)

Group-Exercise:

1)Write down evolutionary adaptations for trees that are frequently exposed to low intensity, surface fires

2) Write down what characteristics trees would have that were only exposed to infrequent, high intensity, crown fires

Fire protection is related to three factors:

1) Height

Meristematic Tissue

Longleaf pine budsProtection of apical meristems

Fire protection is related to three factors:

2) Soil Insulation

Fire protection is related to three factors:

3) Bark

thick bark to protect sap layer (cambium) from lethal temps (130

degrees F) during a fire

Factors that influence bark

resistance to fire

1) Ambient temperature

2) Dormant vs. Active Stage

3) Bark Flammability

Factors that influence bark

resistance to fire

4) Bark Reflectivity

5) Fire Frequency

6) Fire Intensity

Fire scar on Sequoia

post fire environment is different

1) increased productivity

2) increased flowering

3) seed dispersal

Russian Knapweed seeds

Seeds-dehydrated & metabolically dormant

4) synchronous release of canopy stored seeds

5) Synchronous release/germination of soil-stored seeds

 

6) increasing establishment of seedlings

Adaptations of Undergrowth Plants Rhizome: regenerative buds located on undergound stems

Amelanchier spp.

1) Survivors

Adaptations of Undergrowth Plants

Symphoricarpus spp.

Linnaea borealis Arctostaphoylos uva-ursiHave shallow regenerative buds that are susceptible to fire

Vulnerability to lethal heating1) location2) size

Spiraea

Regenerative buds located more than 2 inches below the soil surface

Ribes (gooseberries, currants)

Adaptations of Undergrowth Plants

1) Colonizers

RESIDUAL COLONIZERS-species that are found in burned areas but were not previously growing there prior to burn

Wild TobaccoNicotiana attenuata

-Present in the seed bank

-Smoke cue for germination

seed coat resists water and heat and protects the seed embryo for 200-300 years buried in the soil

OFFSITE COLONIZERS-regenerate from seed blown in or transported into a burn area

Scouler willow

Bull Thistle Seeds

Cheatgrass (Bromus tectorum)

How does fire affect wildlife?

1) Direct (death, injury)

2) Indirect (loss or alteration of habitat)

Ability to Survive depends on:

1) Mobility

2) Ability to Seek Shelter

Ability to Survive depends on:

3) Arboreal dwelling

4) Physiologic avoidance (aestivation)

Sonoran Desert Toad

Main effect of fire on animals is on their habitat

Habitat-Resources needed to support a viable population over space and through time

4 Components

1) Food

2) Cover

3) Water

4) Space

Benefits of Habitat-Kirtland's warbler

Detrimental Effects of Fire to Habitat-Mexican spotted owl

Habitat Trade-offs

Migrating birds flock to grasslands treated with prescribed fire. (USFWS)

http://www.youtube.com/watch?v=3vrTRg3WnDI

2009 Victoria, Australia Fires

wombat

Kangaroo corpses lay scattered by the roadsides while wombats that survived the wildfires' onslaught emerged from their underground burrows to find blackened earth and nothing to eat. Wildlife rescue officials worked frantically yesterday to help the animals that made it through Australia's worst-ever wildfires, but they said millions of animals likely perished in the inferno. Scores of kangaroos have been found dead around roads, where they were overwhelmed by flames and smoke while attempting to flee, said Jon Rowdon, president of the rescue group Wildlife Victoria. Kangaroos that survived are suffering from burned feet, a result of their territorial behavior. After escaping the initial flames, the creatures - which prefer to stay in one area - likely circled back to their homes, singeing their feet on the smoldering ground. "It's just horrific," said Neil Morgan, president of the Statewide Wildlife Rescue Emergency Service in Victoria, the state where fires were still burning. Some wombats that hid in their burrows managed to survive the blazes, but those that are not rescued by humans face a slow and certain death as they emerge to find their food supply gone, said Pat O'Brien, president of the Wildlife Protection Association of Australia. "We've got a wallaby joey at the moment that has crispy fried ears because he stuck his head out of his mum's pouch and lost all his whiskers and cooked up his nose," Rowdon said. "They're the ones your hearts really go out to." In some of the hardest-hit areas, rescuers used vaporizing tents to help creatures whose lungs were burned by the searing heat and smoke.

4:50 am

9:01 am

9:10 am 11:12 pm

9:45 am Santa Ana winds trigger camera

California scrub drainage, 2007, wildlife motion

detectors