Alapai soils
are less rocky with 0–10% rock fragments by volume in the first
150 cm and no important lava rock component in the first 18 cm.
The Kulalio soils typically have 50–90% a’a lava rock fragments to
the same depth and are characterized as having 5% a’a stones at
the surface, 10% a’a stones in the first 0–8 cm, and 30% a’a fragments
from 8 to 18 cm depth. They also differ in mean annual soil
temperature: the Alapai series has a mean of 16–20 C and the
Kulalio, 12–18 C.