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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.
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What is Evolution?? All changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today.
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
Populations Evolve, Natural Selection Occurs at the Level of Organisms
Three factors that influence rates of evolutionary adaptation 1) 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: • 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
Protection of apical meristems Longleaf pine buds
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
Seeds-dehydrated & metabolically dormant Russian Knapweed seeds
Adaptations of Undergrowth Plants Rhizome: regenerative buds located on undergound stems
Adaptations of Undergrowth Plants 1) Survivors Amelanchier spp. Symphoricarpus spp.
Vulnerability to lethal heating 1) location 2) size Arctostaphoylos uva-ursi Linnaea borealis Have shallow regenerative buds that are susceptible to fire
Regenerative buds located more than 2 inches below the soil surface Spiraea
Adaptations of Undergrowth Plants 1) Colonizers RESIDUAL COLONIZERS-species that are found in burned areas but were not previously growing there prior to burn Ribes (gooseberries, currants)
Wild Tobacco Nicotiana 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
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
Habitat-Resources needed to support a viable population over space and through time 4 Components 1) Food 2) Cover 3) Water 4) Space
http://www.youtube.com/watch?v=3vrTRg3WnDI Migrating birds flock to grasslands treated with prescribed fire. (USFWS)
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.