Technical Report #167.
Loh, R., A. Ainsworth, T. Tunison, and C. D’Antonio. September 2009.
Testing native species response to fire – a first step towards
building fire resilient native plant communities at Hawai’i
Volcanoes National Park
912 KB
ABSTRACT:
Wildfires, fueled by fire-adapted alien grasses, result in the loss of
native tree and shrub species in the dry and seasonally dry communities
of Hawai‘i Volcanoes National Park. Future wildfires and further loss of
native plant diversity is expected given the prevalence of alien grasses
in the area. Fire-tolerance, defined in this paper as the ability to
survive or colonize after fire, was evaluated in seven controlled burns.
Seed germination in response to oven heating was tested in laboratory
experiments. Fourteen of 19 native species showed some capacity to
survive or colonize after fire. Seedlings of eleven species were able to
establish from seeds placed in the field prior to or immediately
following controlled burns (Argemone glauca, Bidens hawaiensis,
Canavalia hawaiiensis, Dodonaea viscosa, Myoporum sandwicense,
Osteomeles anthyllidifolia, Santalum paniculatum, Scaevola kilaueae,
Sida fallax, Sophora chrysophylla, Sesbania tomentosa). Seven
species survived beyond the first year including six that reached
reproductive maturity (Argemone glauca, Bidens hawaiensis, Canavalia
hawaiiensis, Dodonaea viscosa, Sida fallax, Sophora chrysophylla).
Seeds of ten species tested in oven-heating experiments showed either a
positive or neutral germination response to mild heating (90 ºC), among
these were three species (Myrsine lanaiensis, Rhus sandwicensis,
Senna gaudichaudii) not tested in the field. Testing species
response to fire is the first step toward building resilient native
plant communities in the new fire regime established by alien grasses at
HAVO.
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