Invasive Species

To Get a Feel for the Invasive Species Zone

Examples of forests dominated by invasive species can be seen along the Hāna Highway. Notice the huge patches of bamboo, the thick strawberry guava stands, and the bright orange flowers of the African tulip tree reaching far up the mountain. These species have replaced the native plants and trees that once flourished here.

Here is a perspective on invasive species written in April 1986 by Sam ‘Ohu Gon III, senior scientist / cultural advisor to The Nature Conservancy:

A World of Weeds

When we go hiking, we are some times lucky enough to see a portion of trail that has almost no weeds on it: almost purely native plants, a canopy of ‘ōhi‘a in red bloom above. At our feet the roots meander across the trail, packed with wet mosses and small ferns, dozens of different kinds of them in a small space between two trees. An ‘ōlapa trembles in the wind, flashing sunlight off of glossy, oscillating leaves, and a tall hāpu‘u, with purple-red bristles, sends large fronds above our heads, dappling the sunlight below, where orange-berried makole sends its offshoots among the liverworts. The cool smell of growing plants and spongy leaf litter combines and moves on a ko‘olau breeze…

Most of all, we get a feeling of balance. What a diversity of living things, and not too much of any one of them. Sometimes I envision just a couple of square meters of it, that’s all, not too much to ask…placed in a small corner of the yard, there to be the model for any gardener, and almost impossible to duplicate or maintain because of the narrow requirements of temperature and moisture. And because of weeds. In a month, even if all of the mosses could persist, the dandelions, Spanish needles, three-leafed clovers, and beggar’s ticks would be in there. Weeds.

But what’s a weed? Something that’s growing where it is not wanted. The rarest prairie wildflower, introduced to the native subalpine grasslands of Haleakalā, might be a weed there. We can all appreciate what trouble weeds can be. Maybe we are already aware of banana poka, a passion-fruit relative, climbing like a blight over the tops of koa-‘ōhi‘a forests on Hawai‘i Island. It hogs the light, so that under its green net are sun-starved native plants, skeletons of trees, open soil. Or perhaps we have walked through an unexpected blackberry patch on Ka‘ala, or in Kōke‘e, and recalled adjectives and dark thoughts while nursing thorn-shredded arms and legs. Or we’ve seen the sad spread of Clidemia on O‘ahu, Moloka‘i, Maui, and Hawai‘i: gulches full of nothing but purple berries and crinkled leaves, where we once breathed in the scent of native mints in full bloom. Aloha ‘ino!

Why is it that weeds always grow so fast? Taste so bad? Prickle and poke? It is their strategy. They are colonizers, adapted to establish a foothold and hold it in a disturbed situation: a landslide scar, or scoured flood plain. And we are great disturbers, too, aren’t we? Road builders, sub-dividers, and yes, trail builders too. Is it any accident that Clidemia followed O‘ahu hikers and hunters on their trips to Wailau and Waimanu?

We are the keepers of the land. We need to make a choice. For me, I have made a judgment that a native plant, no matter how plain-flowered, how small, how unremarkable, is inherently more valuable than any ornamental. Oh, there are beautiful introductions to be sure! But so many of them are splashes of color, spectacular to experience, and striving to out-do. But there is much to say about subtle beauty too. A concert of diversity in a native forest is a hum of quiet harmony and delicate shades.

Well, we can make a choice. I can envision a horrid world, where the only things that have been able to survive with humans are those things that we couldn’t weed out: the thorniest things, the most poisonous, the things that crowd other things out, the cockroaches and flies, the things that thrive under our streets and on our waste. It is a world that comes if we don’t care. Because when we don’t watch the garden, the weeds come in.

Or, there is a world in which we value and care for native diversity because it makes us richer. We can listen to clear waters drip from mosses into a cold mountain pool, watch ‘ōpae sweep the rocks for algae, see a kanawao with tiny white flowers at its roots pollinated by diminutive beetles that work the soil. We can all stand to learn what is really valuable in our islands: a diversity of things found nowhere else in our wide world, and a beauty that is the antithesis of neon-emblazoned ideas of what is visually appealing.

And the best thing is that these riches are not gotten via corporate maneuvering, labor unions, or business degrees. We can all enjoy these riches without kicking someone else off a ladder. Mai e loa‘a i ka waiwai o ka ‘āina – Come partake of the riches of the land.