Kilauea’s 2018 eruption buried 13.7 square miles of Hawaii’s Big Island under molten rock that could melt copper. The lava cooled into a lifeless black crust that looked about as hospitable as the surface of Mars.
Here’s the thing: that wasteland is now carpeted with ferns.
When Rock Decides It Wants to Host a Party After All
The first colonizers aren’t plants at all—they’re cyanobacteria, those microscopic overachievers that have been terraforming Earth since 3.5 billion years ago. They show up on fresh lava flows within months, sometimes weeks, forming biological crusts thinner than a coat of paint. These photosynthetic squatters don’t need soil. They make their own food from sunlight and pull nitrogen straight from the air like tiny atmospheric miners.
Wait—maybe that sounds too simple.
Because the real alchemy happens in the cracks. Lava doesn’t cool uniformly; it fractures into a million tiny fissures where moisture collects and temperature fluctuates. Lichens—those weird fungus-algae partnerships that nobody can quite categorize—wedge themselves into these gaps and start secreting acids. Actual acids. They’re literally dissolving rock, transforming basalt into something that could charitably be called proto-soil. Scientists studying the 1959 Kilauea Iki eruption found lichen colonies established within five years, already breaking down minerals that took milenia to form.
Turns out, volcanic rock is suspiciously nutritious once you crack it open.
The Ferns That Apparently Have No Chill Whatsoever
Hawaiian ferns—particularly the native ʻamaʻu (*Sadleria cyatheoides*)—behave like they’re in some kind of race nobody else signed up for. Their spores drift on wind currents for miles, landing on year-old lava flows and somehow deciding this hellscape looks like home. They don’t wait for topsoil. They germinate directly on rock surfaces where their roots snake through cracks, following moisture deep into the volcanic substrate. On flows from Mauna Loa’s 1984 eruption, researchers documented ʻamaʻu seedlings within 18 months.
The secret? Mycorrhizal fungi.
These underground networks partner with plant roots, extending their reach and nutrient absorption by orders of magnitude. The fungi get sugars from photosynthesis; the plants get access to minerals locked in volcanic glass. It’s a transaction so ancient it predates trees—fossils show similar partnerships existed 400 million years ago. On fresh lava, this collaboration accelerates everything.
When Seeds Arrive in the Stomachs of Birds Because Evolution Is Weird
Native Hawaiian honeycreepers and ʻamakihi don’t avoid new lava flows; they patrol them, hunting for insects that colonize these barrens surprisingly fast. The birds eat native berries—ʻōhelo, pukiawe—and deposit seeds in convenient fertilizer packets across the sterile landscape. Botanists studying Hualalai’s 1801 flow found mature ʻōhelo shrubs (*Vaccinium reticulatum*) scattered across the aa lava in patterns that mapped precisely to bird perching sites.
That’s about as elegant as ecological engineering gets.
Meanwhile, wind-dispersed seeds from ʻōhiʻa trees (*Metrosideros polymorpha*) land everywhere, but only germinate where conditions hit a narrow sweet spot: enough moisture, sufficient shade from afternoon sun, protection from the salt-laden trade winds. The result? Clusters of seedlings in apparently random locations that turn out to be microhabitats with their own microclimates, their own fungal networks, their own rules.
The Timeline That Refuses to Follow Anyone’s Schedule Properly
Conventional ecological succession theory suggests this process takes centuries. The data says otherwise. Mount St. Helens’ 1980 eruption deposited sterile pumice across 230 square miles; lupines appeared within two years. Iceland’s Surtsey island emerged from the ocean in 1963 as bare volcanic rock; by 1965 it had vascular plants.
But here’s where it gets strange: older doesn’t always mean faster recovery. Hawaii’s newest flows sometimes green up quicker than thousand-year-old aa fields that remain stubbornly barren. The difference? Rainfall patterns, rock chemistry, elevation, the specific cocktail of minerals in that particular eruption. Lava from Kilauea’s east rift zone has different silicon content than summit flows, which changes how quickly it weathers, which determines what can grow and when.
Climate matters too, obviously. Wet windward slopes collect 200+ inches of rain annually, accelerating every chemical reaction, every spore germination, every fungal colonization. Dry leeward flows might take decades to accumulate enough organic matter for the same result.
The real lesson? Life doesn’t wait for permission. It shows up uninvited, breaks down doors, rewrites the rules, and turns geological debre into gardens before anyone thought to say it was impossible.
