After fire, first things first: stabilize health, safety, property, infrastructure & soil.
The urge to help after fire is a powerful force that can be harnessed into positive action by and for affected communities. Swift private and public support for the physical, financial, emotional and economic well-being of our affected communities is paramount. In the aftermath of evacuation and recovery, communities and responders are often dealing with hazardous environmental conditions which call for vigillant public safety and environmental stabilization. Specifically, communities must avoid contact with contaminated water, soil and hazardous materials in and around affected areas. Learn how to protect yourself from wildfire smoke and clean up safely after a disaster.
For long-term wildfire risk mitigation planning, supporting agriculture and reducing fuels around your home and community are key.
Stabilizing soil to prevent wind and water erosion is the most important environmental consideration in addition to remediating existing hazardous materials after fires. (see the next section) However, the role that farms and ranches play in land care is critical across fire prone landscapes. Ranches and farms keep fire-prone weeds at bay to maintain pastures and crops. For example, if cattle pastures during the August 2023 Kula fires on Maui had been abandoned, natural resource managers tell us they would have become dominated by multistoried seeding grasses, as well as invasive Lion's ear (Leonotis nepetifolia), gorse (Ulex europeaus) and various fire-prone wattle and eucalyptus trees. Increased wildfire fuels (grasses, shrubs and trees) on unmanaged landscapes dramatically increases fire intensity. For example, burning koa haole trees (Leucaena leucocephala) can throw embers and create spot fires, especially during high wind events. Learn how to protect your home and community by visiting the Hawai`i Wildfire Management Organization.
What is your emergency soil stabilization plan? This can be done in various high-tech and low-tech ways.
After human health and safety, the first priority is to protect the soils from rain and run-off. According to U.S. Forest Service research, mulching with wood chips is an effective, short-term solution but may be difficult to apply over large areas. Fallen plant debris can also be spread across burned areas to provide some protection. In sections that burned very hot, a water repellent layer may form on the top of the soil. This can be tested easily by pouring water onto burned soils: if the water pools on the surface, then it is considered hydrophobic (water will not penetrate). In these areas, nutrient availability (like phosphorus) for the successful growing of plants may also be affected after fire.
In severely burned areas and steeper zones, contour felling of dead trees or using fiber rolls and straw wattles can help slow down water movement and downslope soil loss. Steep slopes can also be stabilized with check dams, jute bags, hydromulch, erosion control mats and silt fences. More detailed info on applying these methods can be found here for burned landscapes and here for protecting your home from post-fire erosion and debris flows. Wherever possible, use local materials and best management practices (see below) to minimize the potential of moving invasive pests.
Consider re-vegetating burned areas in a way that makes sense for your community's unique ecology with the understanding that resources (time, money, long-term stewardship) may vary.
Re-planting is an important, long-term strategy for soil stabilization. Keep in mind, the site will likely be colonized by many short-lived weeds either present in the soil seed bank, or dispersed into the site afterwards. These may be a benefit in the short-term, but may not be desirable. Plant material availability is the biggest limiting factor for post-fire re-vegetation, especially for native plants. For example, many post-fire plans recommend re-seeding with non-invasive grasses. However, the availability of native Hawaiian grasses such as pili (Heteropogon contortus) or kawelu (Eragrostis variabilis) are limited and would likely need to be collected yourself. Another option is seedless, non-invasive vetiver grass, which is highly effective at erosion control, but must be planted as ‘plugs.’
When re-planting, limit the spread of invasive pests. If you are growing plants, it is important to ensure your pots and soils are sanitized, as there is also high potential for transporting pests. The following guidelines are important:
1. Prevent the spread of Little Fire Ant (LFA) , coqui frogs, Coconut Rhinoceros Beetles (CRB), and others by:
- Ensuring that any contract work requires equipment cleaning and materials inspection prior to work and site inspections to assess compliance efficacy prior to job completion/payment.
- Ask if the contractor or vendor follows BMPs for invasive species, and ask for a copy to review.
- Ask about a contractor or vendor’s previous job location/s and the known invasive species in that area. Coqui, Little Fire Ants, Coconut Rhinoceros Beetles, and weeds have all been moved to new locations on heavy equipment and materials from infested job sites.
- When purchasing or selecting materials, source plants, planting materials, and similar supplies from uninfested areas and/or from vendors that implement pest BMPs, or ones that are working under official pest mitigation compliance agreements.
- Quarantine and survey all new plants and materials for pests before outplanting, e.g. listen at night for coqui, look for CRB and damage HERE, and test all new plants for LFA by clicking HERE.
2. Prevent the spread of Coconut Rhinoceros Beetle from palms, mulch, compost, etc. coming from O`ahu or Kaua`i by:
- Being aware that CRB lay their eggs and their grubs (larvae) develop in compost, mulch, greenwaste, manure, etc.). Specify in your contract or purchase agreement that the materials receive proper treatment (e.g., chipping, grinding, heat treatment, or fumigation), and also specify that the vendor/shipper must comply with all applicable laws and rules when moving these items.
- Inspecting upon receiving and while working with these materials and installation sites. Conduct regular searches/inspections (at least every 4 months) of the material for any signs of CRB grubs or pupa (in mulch, greenwaste, and soil mixes/growing media, or damage to the leaves or crowns of coconut trees or any type of palm, banana, and hala.
- If working with tree trimmers, landscapers, or similar, consider asking that all personnel be trained on what to watch for and how to report it. Adult CRB bore golfball-sized holes in coconut and other palms and the leaves may show signs of beetle damage. CRB can also bore into banana plants, hala trees, and many other trees. Text or call (808) 679-5244 or [email protected]. Click HERE for more information.
3. Avoid fire-promoting and invasive plants by checking if what you want to plant is on the Plant Pono website HERE. The website also lists nurseries on Kaua`i and Hawai`i island which are "Pono Businesses." To check if it is fire-promoting HERE.
While native Hawaiian plants are always desirable, they require a great deal of care, such as water, fencing and weeding. Keep in mind that invasive grasses and herbs will out-compete native species. Even faster growing coastal Hawaiian shrubs such as a`ali`i (Dodonaea viscosa), naupaka (Scaevola taccada), and ground cover such as `uhaloa (Waltheria indica) require vigilant weeding. It is important to understand that without fences, pigs and goats (deer on Maui and Lāna`i, sheep on Hawai`i Island and Lāna`i) may eat, root and disturb these plants, although some coastal plants like milo (Thespesia populnea), kamani (Calophyllum inophyllum) and naupaka may be less desirable to ungulates. Ecosystem preparation (soil nutrient considerations, soil stabilization, and preferably fencing) and a long-term commitment to weeding (manually or with herbicide) is required to make native species restoration a success.
What about direct seeding with native plant species?
Scattering limited amounts of native seeds only works in areas without invasive species, timed with adequate rainfall. Often times, burned areas have aggressive alien grasses, herbs and shrubs which will out-compete native seeds scattered by people. Most grasses will re-sprout from the roots, so they easily outcompete scattered seeds, only a small percentage of which will grow into plants. Many seeds will be eaten by both rats and birds. In addition, seeds scattered on steep slopes are likely to wash into gullies with the first rain. Native tree seeds which may be slower growing might not sprout right away. Until we have access to large quantities of seeds, the best use for limited quantities of native seeds is to grow them into individual plants and out-plant them with the intention of long-term protection, weeding and care.
Where can I get plant material?
If you are in need of immediate materials, you can often find common coastal species such as milo, kamani, or non-native, non-invasives like monkey pod tree (which produces hundreds of seedlings). Only a small fraction of plants in these ‘seedling banks’ will actually mature to adult trees. These can be quickly and gently harvested, potted up, and transplanted. Please use your discretion and ideally collect on private lands with landowner permission.
If you are in need of native species, calculate your need and consult with professionals. It is important to know that individual nurseries are often seed limited, so they don't usually like to sell seeds (they are trying to sell seedlings). When re-planting with natives, try to source them from your area or island.
However, some outlets sell plant materials as follows (not a complete list):
Hawai`i Island Seed Bank does sell Hawaiian dry forest seeds to Hawai`i Islanders only.
Ho'olehua Plant Materials Center, Moloka`i
Maui Nui Botanical Garden, Kahului, Maui
Maui Native Nursery, Maui (wholesale only)
Hui Kū Maoli Ola, O`ahu