Book Excerpt: 'Intelligent Tinkering' By Robert Cabin
Hawaii is home to one of the world’s last dry tropical forests. In their prime, these magnificent ecosystems were bastions of biodiversity. Now, only 10 percent of the state’s original dry forests survive. In Intelligent Tinkering, Robin Cabin, an associate professor of ecology and environmental science at Brevard College and a former restoration ecologist for the U.S. Forest Service, draws on his own experience in doing restoration work in the few remaining Hawai'ian dry forests.
Below is the excerpted first chapter from Intelligent Tinkering, by Robert Cabin. August 2011, Island Press.
I could see the charred remains of the ghost forest from the highway. One mile below me, the dead trees rose from the lava like giant skeletons. There were many reasons not to walk down there: the steep slope, the intense heat, the dark and foreboding lava, the dense swath of neck-high African fountain grass I would have to fight my way through to reach the 200-year-old lava flow that ran down to the ruined trees. More than all of this, I didn't want to go because I'd been in Hawaii long enough to visualize the ecological devastation I would see when I got there. But something I could no longer ignore compelled me to go.
I swung my legs over the guardrail, stepped off the highway, and plunged into a sea of dead grass. A prolonged drought on this side of the island had reduced tens of thousands of acres of formerly lush fountain grass (Pennisetum setaceum) to a brown wasteland. Head down, I trudged toward the lava as if walking against a strong, waist-deep current. Inside the tunnel of grass, the air felt heavy and smelled like rotten hay. The brittle stems scratched at my bare arms and legs; after ten minutes I felt the familiar sting of sweat trickling into my blood.
When I reached the flow, I could feel the heat radiating from the black rock through the thin soles of my shoes and into my blistered feet. I paused to brush the fountain grass debris off my face, gulp down some water, and look around. My eyes followed the meandering route of the lava flow past the burned forest and all the way down to the sparkling ocean some six miles and 2,000 feet below me. Across the channel, seventy miles northwest from where I stood on the island of Hawai'i (the "Big Island"), East Maui's 10,000-foot Haleakal Volcano rose majestically out of the sea, and I could just make out the faint outlines of the islands of Kaho'olawe, L na'i, and Moloka'i floating on the horizon west of Maui.
I shouldered my pack and set off across the lava for the forest. There are two main kinds of lava in Hawai'i: when relatively fluid magma cools, it forms smooth, solid, ropy p hoehoe, while relatively viscous magma forms rough, rubbly, clinker-type 'a'. Even though this was a somewhat treacherous 'a' flow (falling on this type of lava often results in nasty cuts and gashes), the walking here was much easier and faster than within the fountain grass. When I first began working here as a restoration ecologist for the National Tropical Botanical Garden in 1996, I wore expensive, sturdy hiking boots, but after the 'a' destroyed my second pair I gave up on the concept of ankle support and switched to cheap, low-cut sneakers. Eventually I acquired my "'a' legs" and rarely fell except when I let my eyes and mind wander too far from my feet. Fifteen minutes into this hike, when I tripped over a loose piece of lava and nearly stumbled into a jagged ravine, I realized with a jolt that I had been looking at the coast and daydreaming about the ocean. It had been far too long since I'd swum and surfed and snorkeled in those waters.
The lowland, dry, leeward sides of all the main Hawaiian islands were once covered by magnificent forests teeming with strange and beautiful species found nowhere else on Earth. Tens of thousands of brightly colored, fungi-eating snails slithered through the trees and inched their way through the dark underlying leaf litter. Vast flocks of giant flightless geese squawked across the forest understories; dozens of species of finchlike honeycreepers sipped nectar, gobbled insects, and sought shelter from the heat and hungry eagles, hawks, and owls.
Paradoxically, the diversity of Hawai'i's primeval dry forests was probably created and maintained by rivers of red-hot molten lava that destroyed everything in their path as they wound their way down the slopes of the volcanoes and into the sea. Before alien species such as fountain grass reached these islands, the native plant communities apparently did not produce enough understory biomass to carry fires much beyond the lava rivers, so the forests on either side of the flows remained more or less intact. Thus, as each wave of new lava cooled and weathered, it was slowly colonized by the species in the adjacent forests. The result of thousands of years of this dynamic cycle was a mosaic of different-aged forests, with different species assemblages growing sometimes literally side by side.