The two youngest chronosequence sites, Thurston and Olaa, have soils that were formed from tephra associated with the shield-building phase of the volcano Kilauea.
The next site on the soil chronosequence is located in the southwest corner of the Olaa Forest, which is also associated with Kilauea volcano within the boundaries of Hawaii Volcanoes National Park.
The pubescent varieties make up [approximately equal to]95% of the Metrosideros at the Thurston site, 30% at Olaa, 40% at Kohala (hairs caducous), and 5% at Kolekole.
The two youngest sites, Thurston and Olaa, are situated on the gentle-sloping, undissected shield of Kilauea.
While the Thurston and Olaa soils were clearly developed on recently formed landscapes, the four older soils of the chronosequence developed partially or entirely on erosional surfaces; the implication is that although the parent material of the Kokee site may be 4.1 x [10.sup.6] yr old, development of at least part of the present soil was initiated more recently.
We established 2-4 study plots within a 1-ha area at each of the field sites except for Olaa; several of the measurements took place in these study plots, while others were carried out in the 1-ha area surrounding them.
Duplicate samples of 0.50.6 g of soil (triplicates for Olaa) were weighed out at field moisture into 50 mL polypropylene centrifuge tubes.
The Olaa soil fractionations, which were carried out at a later time than for the other soils, involved the same procedure except that we excluded the sonicated NaOH and hot HCl steps.
Since the Olaa fractionation did not include sonic NaOH or hot HCl fractions, all residual [P.sub.o] and [P.sub.i] was measured in the final [H.sub.2]S[O.sub.4]/[H.sub.2][O.sub.2] digest.