A Mid-Elevation Woodland and Succession on the 1974 Flow

Eruptions from Southwest Rift in 1974 occurred at about the 4,000 ft. elevation.  You can see this flow from near the top of the Chain of Craters Road.  This recent flow cut through a mid-elevation woodland. 

This site combines an examination of this forest and the lava flow.

Succession is the process of change in a plant community.  There are a number of types of succession; here you'll see primary succession.  This refers to the process of species colonizing a new (i.e., previously not vegetated) substrate.

Pioneer species are those that typically invade new substrates.  You'll see several of these pioneers.

Getting There

Travel on the Crater Rim Drive to the Chain of Craters Road. 

Go down the Chain of Craters Road.  You'll only go a short distance, so proceed slowly. 

About 200 yards down the road you'll see a trail (the Crater Rim Trail) that cuts across the road and enters the forest.  This is marked with a sign. 

About 100 yards farther down the road you'll see the lava flow ahead. 

Find parking on the right side of the road just before the lava flow

If you go too far, you'll see the sign marking the lava flow.

You will start by walking through the forest, so walk back up the road toward the Crater Rim Road. 

You'll return to your vehicle along the lava flow.  The total distance is less than a mile. 

Parking along the Chain of Craters Highway
Sign marking the 1974 lava flow The Chain of Craters Highway heading back toward the Crater Rim Road

Warnings


This site is organized by dividing it on three web pages.


The Woodland Along the Highway Roadside

The short walk along the highway provides an opportunity to look at some of the plants that are characteristic of this mid-elevation woodland.  Some are seen here that won't be seen once you start the trail through the woodland, so this can be a productive time if you are alert.

The knotweed (Polygonum capitatum) is found alongside the road.  Like a lot of other plants found along highways, this one is generally restricted to this habitat.  It is likely that the extra water provided by runoff from the paved roadway contributes to this distribution limitation in this area.

There are a number of grasses, for example, that share this roadside habitat.

Polygonium capitatum
The forest on that you are passing through is dominated by Metrosideros polymorpha (Hawaiian: `ohi`a).

The trees along the road are tall and closely spaced, making this a closed-canopy forest.

The picture on the right is a view to the left of the highway.

Metrosideros polymorpha in the woodland
You will notice Acacia koa (Hawaiian: koa) trees in this forest, too. 

In some areas Metrosideros polymorpha (Hawaiian: `ohi`a) and Acacia koa are a co-dominant species.  The height of the two species is similar and they are mixed together through the woodland.

You can recognize the Acacia koa by the lighter green, sickle-shaped phyllodes.

Acacia koa and Metrosideros polymorpha in the woodland
Look for the pedestrian crossing sign on the right side of the highway.  When you turn and face this sign, you'll see several large faya trees (Myrica faya). The leaves are a lighter color and, if you cross the road to examine it up close), and if you sort it out from the surrounding canopy, you'll see its pyramid-shaped life-form.  The abundance of this species increases rapidly as you drive further down the Chain of Craters road.
Pedestrian crossing sign Myrica faya
Near this site, on the right side of the highway, you might be able to find a patch of the alien strawberry (Fragaria vesca).  There is another patch on the left side of the road near the entrance to the woodland trail.

There is a native strawberry subspecies (F. chiloensis ssp sandwichensis; Hawaiian: `ohelo papa).  The alien plants have their flowers and fruits above the leaves (Lamoureux 1996: 28).

The litter shows a mixture of Metrosideros polymorpha (Hawaiian: `ohi`a) and Acacia koa (Hawaiian: koa) debris.

Fragaria vesca
Fragaria vesca Fragaria vesca
Another alien invader, fortunately not abundant in this area, is the kahili ginger (Hedychium gardnerianum).  It is also found in this area of the forest on the right side of the road.
Hedychium gardnerianum Hedychium gardnerianum
Proceed to the trail that crosses the road.  You'll recognize that you're at proper place when you see this sign.

We'll be following the trail to the left side of the highway.

Trail sign

Continuing Links

Field-Trip Questions

References

 


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Last Updated: 07/31/02

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