Reforesting Mauna Kea

Last week I took the opportunity for a new experience: helping plant trees with the Mauna Kea Forest Restoration Project. For background, much of the high-elevation slopes of Mauna Kea was originally upland forest. A lot of that forest was later cleared for grazing cattle or as a result of grazing by invasive ungulate species; I don't know the exact details, but the point is that a lot of former upland forests is now upland grasslands. Montane prairie? (It does tend to remind me of the prairies of Nebraska when I'm up there, and a co-worker mentioned it reminded him of Scotland.) I'm sure there's a term for it.

Anyway, the location this time was the Kaʻohe Restoration Area on the west side of Mauna Kea about 6,000 feet (~1,800 meters) up. The area is part of the habitat range of the endangered palila, of which only a few hundred individuals remain (mostly in the wild, though there's also a captive breeding program). The hope is that, by restoring the forests that originally blanketed the mountain slopes, palila and other various endangered native birds will have more habitat available and able to expand their ranges. The area we were planting in was directly along the highway running between Saddle Road and Waimea, so it'll be easy to spot the trees growing in future while driving by.

Drone view from above Puʻu Ahumoa, a cinder cone up mauka (uphill) of where we were planting.

This time we were planting koa seedlings, a tree in the Acacia genus endemic to Hawaii famed as a hardwood for making canoes, surfboards, and other things (and unusual for being a thornless Acacia). The seedlings were either one or two years old (I think the latter), and already a few feet tall. We started with 800 seedlings, and despite having only about half the number of people who'd signed up we managed to plant 765 of them over the course of about five hours. (And only stopped because we ran out of gas for the portable hole drillers and didn't have a means to manually dig holes!)

My first tree planted!

Interestingly, I learned that koa have “baby” and “mature” leaves, though the mature type are not true leaves, but actually phyllodes – enlarged and flattened petioles (the leaf “stalk”) which take on the function of leaves. The photo below shows one of a few koa that had been planted in the same location last year to test how well they would grow, and shows both types of leaves on the same plant.

A ~3 year-old sapling showing different leaf types.

The weather was also interesting, being clear and sunny throughout the morning before a cloud rolled in over lunch turning everything misty and foggy (which was pretty typical, I learned from people who'd been there for a lot of plantings). Last year's archaeology experience gave me a good idea of how to prepare, though being well above rather than below sea level meant the sun was completely unforgiving. (I missed a patch of sunscreen just below one eye, with the resulting sunburn Wednesday morning looking humorously like I had a black eye.)

Me with seedlings after lunch, to get an idea of the scale.

All in all it was a fun experience, though my knees are still sore a week later from all the up-down-up-down involved. I'd definitely like to go again (after some time to recuperate), though probably not very often as the days it happens are unfortunately mostly during the week (though this occasion was on Prince Kuhio Day, a holiday, so I'll keep an eye out for opportunities). It feels nice to be part of regrowing forests, and knowing that the trees I planted could potentially be seen by people driving by for decades or even centuries to come. We'll see what comes of it in future! A hui hou!