Now that we have had a good round of brush clearing in Launiupoko, it’s a good time to think about what else we can do to protect our precious island from wildfire. Fire is probably inevitable, a spark or lightning strike can set the dry hills ablaze at any time, but we can stop fires before they reach our homes, neighborhoods and farms by using some proven strategies and planting wisely. Fires start readily in dry grass, then spread to harder to ignite shrubs (like Haole Koa) and then ladder up to trees with enough heat and flame to ignite the trees (or homes). This is why we remove invasive shrubs and “raise the skirts” on trees so the fire cannot build on the huge amount of fuel the trees (or homes) provide. But there are other synergistic strategies that can defeat fire.
Fire breaks – are corridors that have been deliberately stripped of fuels like tall grasses, flammable shrubs and dead trees or limbs, and these are implemented as both a preventative fuel management measure and in active suppression efforts to provide a break in fuel, which both slows the fire spread and allows crews to access the fire edge more easily.
Windbreaks – help slow fire’s advance especially in high wind areas like we have in Hawaii. Wind breaks must be tall enough and contiguous enough to actually slow or redirect the wind. Tall, thick and less flammable trees work well for this and can slow a fire’s advance significantly.
Green Firebreaks – (the subject of this article) planted strips of fire resistant vegetation that are strategically placed in the landscape to reduce or stop fire spread. They should be placed as perimeters to valued property or as strips in the line of an anticipated fire’s path (like, in our case, uphill or mauka, since down-mountain wind-driven fire is usually the most dangerous). It is also important to position them along perimeters of property that border wildland invasive grasses and shrubs such as Buffelgrass and Haole Koa. These Green Firebreaks should be continuous enough and wide enough (typically 30 feet or more) to impede the fire’s progression. Green-break plantings can stop a fire’s advance by depriving them of fuels as well as providing a cooler, wetter environment that can snuff out a fire or slow it down enough to fight. They foster a cooler, more humid fungal system that is quite unfriendly to fire. The aim of this approach is also to increase ecosystem resilience within fire prone landscapes.
In choosing vegetation to plant along these perimeters It’s not just the water content, drought tolerance, and fire resistance of the plant that is important, but also the lack of dropping debris. Therefore, for these Green-breaks avoid woody shrubs that drop a lot of flammable litter (such as bouganvilla), but also palms and resinous trees like conifers or pines.
Here are some of the best plants to consider for a property’s or neighborhood’s defensive band (some of the very best are underlined):
Ground Cover (natives)
- Myoporum Parvifolium
- Ihi
- Naupaka
- Pohinahina (Vitex Rotundifolia)
Ground Cover (non-native)
- All varieties of Ice plant and succulents
- Aptenia Cordifolia (Hearts and Flowers)
- Sweet potato vines
- All Agaves
- All Aloe
- Creeping Lantana
- Myoporum
- Wadillia
Native Shrubs
- ʻĀweoweo (Chenopodium Oahuensis)
- Naio (Myoporum Sandwicense)
- Akia
- Ohia Lehua (Metrosideros Polymorpha)
- Uluhe Fern (Dicranopteris Linearis)
- Naio (Myoporum Sandwicense)
- Mamane (Sophora Chrysophylla)
- Aalii (Dodonaea Viscosa)
Trees and Windbreaks
- Bananas ( best fire resistance)
- Podocarpus (best windbreak)
- Citrus
- Olive
- Koa (True Koa
Of course there is no way to guarantee that wildfire will not claim life and property, but every step we take gives us better odds that our neighborhoods will be spared, damage will be limited, or in the event of fire, recovery will be quick.
Let’s all do everything we can to protect each other…
Dr. Dominic Pistillo
mauimistgardens.wordpress.com 