Hawke & Newman—Isotopic enrichment in forest foliage

New Zealand Journal of Botany abstracts

Carbon-13 and nitrogen-15 enrichment in coastal forest foliage from nutrient-poor and seabird-enriched sites in southern New Zealand

D. J. Hawke

School of Applied Science
Christchurch Polytechnic Institute of Technology
PO Box 540
Christchurch 8015, New Zealand
hawked@cpit.ac.nz

J. Newman

Department of Zoology
University of Otago
PO Box 56
Dunedin 9054, New Zealand

Abstract To assess the effect of nutrient inputs from breeding seabirds on forest foliage δ¹³C and δ¹⁵N, we collected foliage samples from two contrasting locations. Olearia lyallii forest on North East Island at The Snares hosts large numbers of (in particular) breeding sooty shearwaters (Puffinus griseus). At Mason Bay (Rakiura/Stewart Island), samples of Brachyglottis rotundifolia, Griselinia littoralis, and Dracophyllum longifolium were collected from two strata within diverse dune forest and one stratum from the open dunes. The δ¹³C results were typical of C₃ plants and did not differ significantly between Mason Bay and North East Island. In contrast, the δ¹⁵N results from Mason Bay (mean ± standard deviation, -6.1 ± 1.7‰) were significantly lower than expected for temperate forest (95% confidence interval of difference, 2.7—3.9‰), and dramatically lower (19.1—21.5‰) than North East Island where enrichments (+14.2 ± 3.1‰) were among the highest ever reported for vegetation.

Keywords Brachyglottis; Dracophyllum; Griselinia; Olearia; Snares; sooty shearwater; Stewart Island

B06043; Online publication date 24 April 2007; Received 25 October 2006; accepted 5 March 2007

PDF file of entire paper: Print-quality (318K) | screen-quality (368K)

This year's abstracts | Journal home page | All abstracts | Publishing home page