Fire Adaptations 5/27/08

Fire adaptation: A review ◊Concept that species have evolved special traits that contribute to ability to survive in fire prone areas ◊Pyrophytes: “fire loving” plants ◊Concept that species have evolved special traits that contribute to ability to survive in fire prone areas ◊Pyrophytes: “fire loving” plants

Adaptations that facilitate survival of the individual TraitFunctionExample Thick Bark Protects cambial tissues from heat damage Ponderosa pine, coast redwood Crown Sprouting Regrowth from dormant buds protected by bark on branches and stems True oaks, coast redwood Basal Sprouting Regrowth from subterranean buds located on roots, rhizomes, or lignotubers Roses, true oaks, coast redwood Buds protected by dense leaf bases Protects buds from heat induced mortality Sword ferns, many grasses

Adaptations that facilitate survival of the Species TraitFunctionExample Dormant Seed buried in soil Dormant seeds with capacity to survive many decades until cracked by fire Manzanita, ceanothus,lupines Fire stimulated flowering Increased reproductive effort in years following fire Many forbes and grasses Seed storage on plant Long-term seed storage on parent plant are released by fire Knobcone pine, lodge pole pine Windborne seedsEarly deposition on post-fire soils Fireweed, woodland groundsel

Three Strategies in Chaparral ◊Obligate resprouters depend on resprouting from underground root systems or bulbs/ tubers to survive ◊Ex. Toyon (Heteromeles artbutifolia)

Three Strategies in Chaparral ◊Facultative seeders both resprout and germinate after fire ◊Ex. Chamise (Adenostoma fasciculatum) ◊Facultative seeders both resprout and germinate after fire ◊Ex. Chamise (Adenostoma fasciculatum)

Three Strategies in Chaparral ◊Obligate seeders are destroyed in flames, depend on seedlings to replace their populations. ◊Many species require a fire cue to germinate ◊Ex. Ceanthus and Tecate Cypress (conifer)

Allelopathy ◊Terpenes: chemicals resins found in many chaparral plant foliage inhibits germination of wildflower seeds ◊Fire destroys these chemicals and helps explain the abundance of wildflowers in recently burned areas ◊Terpenes: chemicals resins found in many chaparral plant foliage inhibits germination of wildflower seeds ◊Fire destroys these chemicals and helps explain the abundance of wildflowers in recently burned areas