
%0 Journal Article
%A Holdaway, R. N. 
%A Hawke, D. J. 
%A Causer, J. E. 
%A Ogden, S. 
%T Soil indicators of pre-European seabird breeding in New Zealand at sites identified by predator deposits
%J Soil Research
%D 1998/12/23
%V 37
%N 1
%P 103-114
%K phosphorus, nitrogen, nitrogen-15, carbon-13, cadmium, procellariid.
%R https://doi.org/10.1071/S98050
%U https://www.publish.csiro.au/paper/S98050 
%X Soil samples (0&#8211;15 cm) from 2 sites identified by palaeontological methods as pre-European seabird breeding sites (Annandale, Ardenest) were compared with a control site (Ngarua; no seabird breeding). All sites had moderately calcareous soils developed on limestone or marble. Breeding site Kjeldahl nitrogen (range, 0&#183;41&#8211;1&#183;4% N) and total phosphorus (range, 1780&#8211;5285 mg/kg P) were comparable to present-day breeding sites and higher than the control (mean, 0&#183;20% N, 520 mg/kg P). Total cadmium (Cd) results followed the same pattern, with results from Ardenest (mean, 0&#183;49 mg/kg) and Annandale (0&#183;47 mg/kg) being similar to fertilised New Zealand pastoral soils. Contributions from extensive pre-European seabird breeding may therefore match superphosphate fertiliser as a Cd source. Results for &#948;15N and C: N were consistent with seabird breeding at both sites (Ardenest, &#948;15N = 8&#183;4 , C:N = 10&#183;6 g C/g N; Annandale, &#948;15N = 6&#183;9 , C: N = 10&#183;6). Results for &#948;13C were consistent with seabird breeding at Ardenest (&#948;13C = &#8211;22&#8211;8 ) but not at Annandale (&#948;13C = &#8211;27&#183;0 ), indicating dilution by organic matter derived from C3 plants at Annandale. The Cd : P ratio was significantly lower (P = 0&#183;05) at each of the seabird breeding sites (Annandale, 6&#183;5 &#177; 1&#183;5 x 10-5 mol Cd/mol P; Ardenest, 2&#183;5 &#177; 0&#183;7 x 10-5) than the control (mean 10&#183;0 &#177; 1&#183;6 x 10-5). This ratio has the potential to complement &#948;15N, &#948;13C, and C: N in identifying and mapping pre-European seabird breeding sites, although more study is required. 
