Premium
Declining foliar and litter δ 15 N diverge from soil, epiphyte and input δ 15 N along a 120 000 yr temperate rainforest chronosequence
Author(s) -
Menge Duncan N. L.,
Troy Baisden W.,
Richardson Sarah J.,
Peltzer Duane A.,
Barbour Margaret M.
Publication year - 2011
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2010.03640.x
Subject(s) - chronosequence , litter , ecosystem , plant litter , soil water , bulk soil , agronomy , abundance (ecology) , soil organic matter , epiphyte , botany , environmental science , biology , ecology
Summary• Patterns in the natural abundance of nitrogen (N) isotopes ( 15 N and 14 N) can help in the understanding of ecosystem processes along environmental gradients, because some processes fractionate against the heavier isotope. We measured δ 15 N in many components of the Franz Josef soil chronosequence in New Zealand to see how each component varied along the sequence and within sites, and to see what this variation can tell us about how ecosystem processes such as N losses change with soil age. • We analyzed δ 15 N in foliage from 18 woody species, abscised leaves from seven woody species, three soil horizons, bryophytes, lichens, bulk deposition, and nodules from the N‐fixing tree Coriaria arborea (Coriariaceae). • Foliar δ 15 N varied significantly across plant species. Foliage and bulk litter became 15 N‐depleted as soil age increased. Soil N from organic and mineral horizons was significantly more 15 N‐enriched than bulk litter N at each site. Increasing precipitation also decreased foliar and soil δ 15 N. • Comparing input and whole ecosystem δ 15 N revealed limited evidence for net fractionation during N losses. These trends are consistent with some combination of increasing fractionation during plant N uptake, mycorrhizal transfer, within‐plant processing, and soil decomposition as soils age.