Living near Fissure 8 has given me a unique opportunity to watch and observe the volcanoes impact on plants and plant communities. Now that the mandatory evacuation zone has been lifted in Leilani Estates, I am able to go around and gather more information closer to the vent. Some of this description will be without photos as I do not want to share photos of others private property during this time of vulnerability.
The plants that thrived through and even produced while the volcano was spewing lava and emissions at my personal residence (1 mile Northwest of the vent) were: avocados, lilikoi, papaya, pineapple, banana and citrus (specifically oranges as that’s the only citrus variety old enough to produce on the property). Plants that seemed to be minimally affected are coconuts, other palms, mango, breadfruit, monstera, soursop and Brazilian cherry.
As you move closer to the vent, coconut palms, avocados, mangos, breadfruit, and citrus seem to be some of the main species holding onto their leaves. These plants are already starting to bounce back with two months of low emissions. Remember it is mostly the emissions that have effects on the plants, the lava itself, will only spare plants it goes around.
Now this is where things get really interesting, the native species. The first plants I noticed dying back were ferns and mosses. The non-native ferns have perished and still have not returned to the property. However, native ferns, specifically the hāpu’u (Cibotium sp.), kupukupu (Nephrolepis cordifolia), uluhe (Dicranopteris linearis) and ‘ama’u (Sadleria spp.) were almost non-effected from the emissions. Mosses still have not regained color and not sure how they are doing just yet. But the tree species never dropped their leaves, and are flourishing with vigor I had never noticed before. Meaning some native plants are more vigorous now than pre-eruption. These species include ‘ohi’a lehua (Metrosideros polymorpha), kōpiko (Psychotria hawaiiensis), māmaki (Pipturus albidus), hala (Pandanus tectorius), ‘ākia (Wikstroemia sandwicensis), and lama (Diospyros sandwicensis). Of the other native species that I’ve planted, who are not 100% part of our young native forest in this part of lower Puna who still thrived are: hame (Antidesma platyphyllum), hō’awa (Pittosporum sp.), loulu (Pritchardia beccariana), koki’o (Hibiscus kokio), naio (Myoporum sandwicense), and ko’oko’olau (Bidens hawaiiensis).
The composition of my under story has changed drastically. Grasses, whom I am not a fan of, have mostly diminished and replaced with honohono (Commelina diffusa) grass. Here in Hawaii, there are two kinds of gardeners, those who like and those who dislike honohono grass!! At any rate, I am enthralled that honohono has filled in. It’s fairly easy to maintain in those more wild parts of the garden, which is in my food forest. Just go around and smash plant material to the ground around your trees and come back later to do it again. I’ve been battling Arthrostemma ciliatum and Melastoma malabathricum who are now weakened or fully eradicated from the property. The most interesting part to me is the defoliation of some highly invasive species, mostly the waiawi (Psidium cattleianum), gunpowder (Trema orientalis), Cecropia (Cecropia obtusifolia) and albizia (Falcataria moluccana). Now all of these species are growing again, however, this opportunity has given all the under story species a chance to obtain much higher levels of light. This means that the native species that have been displaced and hiding in the shade of these dominant invasive plants now have an opportunity to thrive and jump up. This has also given the other trees I’ve planted in the forest an opportunity to jump up too. This defoliation is acting as a pruning, and now that the emissions have slowed, it has invigorated new growth into the forest, sending out growth hormones to all plants in the area. This makes for quite an interesting opportunity to look at our forests for what they should be, more open and airy.
Here is my theory; due to a multitude of plants being defoliated and some plants dying completely, this acted as a pruning and mulching, leaving organic material debris on the ground. The acidity of the rain broke down logs, dead branches, leaves and other things on the forest floor, more rapidly than ever, deteriorating and turning into fertilizer and soils. I can literally go into an area and clear it in an hour, when it would have taken me 4-6 hours pre-eruption to clear. I can go and just smash everything to the ground including large dead ‘Ohi’a trunks. This in turn mixed with the above ground abuse from the emissions putting a temporary hold on the plants growth, somewhat like a winter, and now its ‘early spring’ and everything is growing trying to catch up for lost time. Trees are flushing out leaves and new growth with such abundance that it looks like they’ve been heavily fertilized and pruned to promote new growth! This forest has been in decline due to Rapid ‘Ohi’a Death for years now, but I’m seeing trees re-sprouting from their entire trunks and looking really green and healthy. I’m thinking that the forest needed this kind of abuse to restart and revitalize and become vigorous once again. There is so much mulch, light and airflow entering the forest due to defoliage, making the native trees able to photosynthesis at lower parts of their trunks, also allowing keiki to gather light and grow at speeds they never have before. This, mixed with all the rains we had, lack of pests, nutrients from ash and volcanic behaviors has put most plants in extreme grow mode! We could say that Pele selective weeded, pruned and mulched for us while we were away.
I have planted over 100 different tree species on the property in the past three years. I didn’t lose any trees over 6 inches tall, and plants that were completely defoliated and I thought would perish have come back and put out vigorous new growth. I didn’t even have time to fertilize in the spring and was planning on doing so in May. But the plants are a deep green and looking like they were recently fertilized. I believe the resiliency of my plantings in part has to do with layers, as the older stronger trees were able to hold off some of the effects of the emissions and the younger plants in the lower strata of the forest were able to hide in the shade or coverage of the weedy/taller plants.
My sweet potatoes, Okinawan spinach, Sissoo spinach, edible hibiscus, kalo, turmeric, air potato, kava, cassava, and perennial peanut are flourishing because they were under other species. Now that the light levels have increased these hardy plants are able to send out new shoots or runners to occupy niches that have been left open from the emissions. My lawn is turning into a sweet potato patch. How lovely.
In conclusion, I recommend heavy plantings of native species, coconuts, bananas, pineapples, citrus, breadfruit and avocados, as most of these plants were minimally effected from the lava activity. This follows my ideology of multi-diverse perennial and multi-strata plantings to occupy all layers of the system to allow shelter for younger more vulnerable plants to stay protected from prolonged exposure of emissions. I recommend to all nearby residents to reclaim their yards, pull out the weakened invasives, cut out the dead put on the ground to decompose and give space and time to your plantings, this rainforest is extremely resilient, and will bounce back in time.
Love the forest! Happy Gardening!