Home > Research > Publications & Outputs > Turnover of labile and recalcitrant soil carbon...
View graph of relations

Turnover of labile and recalcitrant soil carbon differ in response to nitrate and ammonium deposition in an ombrotrophic peatland

Research output: Contribution to Journal/MagazineJournal articlepeer-review

Published
  • Pauline M. Currey
  • David Johnson
  • Lucy J. Sheppard
  • Ian D. Leith
  • Hannah Toberman
  • Rene van der Wal
  • Lorna A. Dawson
  • Rebekka R. E. Artz
Close
<mark>Journal publication date</mark>31/08/2010
<mark>Journal</mark>Global Change Biology
Issue number8
Volume16
Number of pages15
Pages (from-to)2307-2321
Publication StatusPublished
Early online date1/07/10
<mark>Original language</mark>English

Abstract

The effects of 4 years of simulated nitrogen deposition, as nitrate (NO3−) and ammonium (NH4+), on microbial carbon turnover were studied in an ombrotrophic peatland. We investigated the mineralization of simple forms of carbon using MicroResp™ measurements (a multiple substrate induced respiration technique) and the activities of four soil enzymes involved in the decomposition of more complex forms of carbon or in nutrient acquisition: N-acetyl-glucosaminidase (NAG), cellobiohydrolase (CBH), acid phosphatase (AP), and phenol oxidase (PO). The potential mineralization of labile forms of carbon was significantly enhanced at the higher N additions, especially with NH4+ amendments, while potential enzyme activities involved in breakdown of more complex forms of carbon or nutrient acquisition decreased slightly (NAG and CBH) or remained unchanged (AP and PO) with N amendments. This study also showed the importance of distinguishing between NO3− and NH4+ amendments, as their impact often differed. It is possible that the limited response on potential extracellular enzyme activity is due to other factors, such as limited exposure to the added N in the deeper soil or continued suboptimal functioning of the enzymes due to the low pH, possibly via the inhibitory effect of low phenol oxidase activity.