A Mid-Elevation Woodland and Succession on the 1974 Flow

This is a continuation of the hike organized as three web pages.


The Mid-Elevation Woodland

This hike continues by starting at the trail head as it enters the woodland.

The forest is dominated by the wide-ranging Metrosideros polymorpha (Hawaiian: `ohi`a).  The forest trees form a continuous canopy.

You can see the leaves of this species in the abundant litter on the trail.

Tree canopy with Metrosideros polymorpha and Acacia koa
Metrosideros polymorpha (trunk) Metrosideros polymorpha (leaf litter)
The round thickenings on the leaves, which are often dark colored, are called galls and are caused by psyllid parasitism. These psyllids are commonly known as jumping plant lice.  They are most common in this area (from 3,000 to 4,000 ft. elevation).  There are three insect species which make these galls.  These are sap-sucking insects. Metrosideros polymorpha (with psyllid galls)
There are also Acacia koa (Hawaiian: koa) trees in this forest.

The sickle-shaped phyllodes (below left) are easily spotted when you look at the forest-floor litter.

At the start of the trail, however, most of the litter is mixed (below right), indicating that both Metrosideros polymorpha and Acacia koa are in the canopy.

Acacia koa (phyllode litter) Mixed litter of Metrosideros polymorpha and Acacia koa
Look carefully near the start of the trail for Psilotum nudum (complanatum??) (Hawaiian: moa, pipi).  You'll find plants growing on the forest floor or as epiphytes in the trees. Psilotum complanatum (??)
The soils are deep at the start of the trail.  There is considerable topography to the forest floor.

The litter is abundant.

There is a patch of the alien strawberry (Fragaria vesca) in the background.

Topography of the forest floor at the start of the trail
Looking down the trail near the trail head, you can see the Metrosideros polymorpha (Hawaiian: `ohi`a) trees on either side of the trail, with a trail border of grasses and shrubs. Trail near the trail head
Dodonea viscosa (Hawaiian: `a`ali`i) is a small shrub here. You'll recognize it by its leaf shape and the presence of three-sided fruits.

The two pictures below are Vaccinium reticulatum (Hawaiian: `ohelo), another common small shrub.  New growth at the tips of the stems of often bright red.  Look for the fruits.  They are round and range in color from bright red to yellow. There are remnant of the flower at the end of the fruit; this is another identification characteristic.

Dodonea viscosa
Vaccinum reticulatum Vaccinium reticulatum
Styphelia tameiameiae (Hawaiian: pukiawe) is another shrub of about the same size. 

You'll see both of these species commonly occurring along the trail and in the forest as you walk through the woodland.

Styphelia tameiameia
Mosses grow on some of the tree trunks and fallen logs. Moss
This set of three pictures shows the view as you continue along the trail.

Notice the slow change from the closed canopy at the start of the trail to one that begins to have distinct openings (right).

Later, you will see that the general stature of the trees becomes shorter (below left).

The soils are becoming shallower as you progress, and the area is probably slightly drier, too.  There is some heterogeneity in the woodland as you will see in some patches with larger or more densely spaced trees (below right).

Along the trail
Along the trail Along the trail
Dodonea viscosa (Common name: hopseed; Hawaiian: `a`ali`i) shrubs are common in the understory at this point.

There are some dense, low growing Dodonea viscosa along the trail shown here with an abundance of leaf litter.

Dodonea viscosa shrubs in the understory Dodonea viscosa shrub with abundant litter
The trail continues with through a mixture of more scattered, short and tall, Metrosideros polymorpha (Hawaiian: `ohi`a) trees.

The understory plants remain fairly dense.

Finally, the forest canopy opens (below right) as the 1974 lava flow is approached.  The forest trees are tall, however, right up to the edge of this fairly recent flow.

Nearing the end of the trail
Understory plants remain large and abundant Forest canopy opens near the 1974 lava flow
Coprosma ernodioides (Hawaiian: `aiakanene) is found creeping over the open forest floor.  The black fruits are particularly attractive.
Coprosma ernodioides Coprosma ernodioides

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Last Updated: 07/31/02