Premium
Natural 15 N abundance of vegetation and soil in the Kapalga savanna, Australia
Author(s) -
MORDELET PATRICK,
COOK GARRY,
ABBADIE LUC,
GRABLY MICHELINE,
MARIOTTP ANDRÉ
Publication year - 1996
Publication title -
australian journal of ecology
Language(s) - English
Resource type - Journals
eISSN - 1442-9993
pISSN - 0307-692X
DOI - 10.1111/j.1442-9993.1996.tb00617.x
Subject(s) - perennial plant , mineralization (soil science) , herbaceous plant , organic matter , legume , soil organic matter , soil water , agronomy , plant litter , vegetation (pathology) , grassland , environmental science , ecology , biology , nutrient , medicine , pathology
The natural abundance of the stable isotope 15 N was measured in different vegetation components and in the soil of a northern Australian savanna. Most of the vegetation was found to be 15 N‐depleted compared to atmospheric N 2 . Herbaceous legumes, perennial grasses, tree legumes, non‐legume trees and annual grasses exhibited mean δ 15 N of − 1.7, − 0.8, − 0.7, 0.0 and + 0.3‰, respectively. These results are in good agreement with previous studies. Legumes exhibit slightly negative values, indicating that they are likely to be nitrogen‐fixing plants. Non‐legume plants have a δ 15 N close to zero, which could equally result from non‐symbiotic fixation, soil organic matter mineralization, or fresh root litter mineralization. In contrast, soil organic matter was 15 N‐enriched. Values of δ 15 N increased with depth and were + 2.5, + 5.2 and +6.1‰ in the 0–10, 10–20 and 20–40cm layers, respectively. Soil organic matter δ 15 N shows a typical profile of mature soils.