Dj. Hawke et Hkj. Powell, SOIL SOLUTION CHEMISTRY AT A WESTLAND-PETREL BREEDING COLONY, NEW-ZEALAND - PALEOECOLOGICAL IMPLICATIONS, Australian Journal of Soil Research, 33(6), 1995, pp. 915-924
Surface soil samples from two sites in a breeding colony of Westland P
etrels were compared with those from a control with no seabird breedin
g. Soil solution (-0.025 mu m) analyses established significant differ
ences in Al, P and natural organic matter (NOM) chemistry. At the bree
ding colony sites, low concentrations of total Al in soil solution, co
mbined with high extractable phosphate, indicated formation of insolub
le humic-Al-(Fe)-P complexes. NOM in soil solution was estimated from
absorbances at 250 nn. NOM was at lower concentrations at the breeding
colony and had a lower percentage of Al bound in non-labile complexes
(38-86% compared with >97%). Gel filtration experiments showed that s
oil solution from the breeding area had an NOM size distribution weigh
ted toward smaller size fractions. This is consistent with NOM having
different properties at the two sites and could contribute to differen
t processes in pedogenesis. The results reported in this paper support
a hypothesis that localized extinction of breeding seabirds following
Polynesian settlement has affected soil chemistry in the well leached
soils on the West Coast of New Zealand's South Island.