Surface soil chemistry at an alpine procellariid breeding colony in New Zealand, and comparison with a lowland site

Abstract

Procellariid seabirds occupied colonies on the pre-human New Zealand mainland from the lowlands to alpine areas, but the effect of geographic environment on soil nutrient cycling has not been investigated. To facilitate qualitative predictions of seabird breeding effects on terrestrial ecology and biogeochemistry, we compared surface soil (0-15 cm) results from a Hutton's shearwater colony at 1230 m with a Westland petrel colony in lowland forest. Soil acidity, total C, total N, total Cd, and Cd excess (the soil Cd which cannot be accounted for by parent material weathering) concentrations were all lower at the Hutton's shearwater colony despite higher burrow occupancy and density. Lower δ 15 N values and higher pH imply that guano was less nitrified in the soil before being lost. At both colonies, parent material contributed a large portion of total P and total Cd. Correlations between total N, P excess and Cd excess with total C suggested that guano nutrient retention is driven by soil organic matter. We conclude that seabird colony location affected the cycling of seabird-derived nutrients in pre-human New Zealand.

Stable isotopic (δ15N, δ13C) analysis of wood in trees growing in past and present colonies of burrow‐nesting seabirds in New Zealand. I. δ15N in two species of conifer (Podocarpaceae) from a mainland colony of Westland petrels (Procellaria westlandica), Punakaiki, South Island

“…The difference between temperate and tropical forests unaffected by seabirds has been attributed to the development of a more open N cycle in tropical forests (Martinelli et al 1999). Soil (Harrow et al 2006) and other ecosystem components at (Hawke & Holdaway 2005) or near (Harding et al 2004) the Westland petrel colony site also have high δ 15 N, consistent with enhanced loss rates and incorporation of marine N into the terrestrial ecosystem.…”

“…N concentrations are 0.4-0.9%, with soil δ 15 N values of c. 14‰ (Harrow et al 2006). Although the soil N concentrations are not unduly high, the δ 15 N values are much higher than in nearby non-petrel soils (Hawke 2004), and are typical of soils in petrel colonies elsewhere (Yoneyama 1996).…”

“…An aerial photograph of the study area is given in Hawke (2004). The colony has a maximum possible age of 740-960 calendar years (Hawke 2004), and was the location of our previous studies on soil chemistry (Hawke 2005;Harrow et al 2006) and isotopic enrichment of the forest community (Hawke & Holdaway 2005). The vegetation included tree ferns (Cyathea spp.…”

Using137Cs and210Pb to characterise soil mixing by burrowing petrels: an exploratory study

“…While estimating by mass is appropriate if mixing is dominated by ion exchange processes (He & Walling 1997), petrels and other soil fauna process soil volumes (Harrow et al 2006). However, evaluating soil mixing by simply considering mixing depth is also instructive.…”

Soil under dead or live organic matter systems: Effect of European shag (Phalacrocorax aristotelis L.) nesting on soil nematodes and nutrient mineralization

“…Islands have a significant value in the study of ecology and evolution and their particular characteristics (small isolated areas, simple biological communities, defined boundaries with surrounding ecosystems) make them suitable places for scientific research (Denslow, 2001). However, to our knowl-edge the effect of seabirds on island soils has been investigated mainly for burrowing seabirds (Mulder and Keall, 2001;Bancroft et al, 2005;Fukami et al, 2006;Harrow et al, 2006), but there are no reports of work on the effect of above-ground nesting birds.…”