Constraints on the Ability of Peatland Ecosystems to Buffer Increasing Nitrogen Deposition

Authors:
Chris Field, Simon Caporn, Lucy Shepperd

Book:
Proceedings of the 14th International Peat Congress

Venue:
Stockholm

Keywords:
deposition, leaching, mineralisation, nitrogen, sequestration

Documentfile:
Field et al 2012: Constraints on the Ability of Peatland Ecosystems to Buffer Increasing Nitrogen Deposition

Summary:

Theme I.  Inventory, stratigraphy and conservation of mires and peatlands

SUMMARY

Over recent years much attention has been given to the carbon balance of peatland and heathland ecosystems and their role as important global carbon stores, yet they are also important for other ecosystem services including as sinks for atmospheric nitrogen pollution . This study contrasted soil exchangeable N and nitrogen losses in leachate at three ericaceous-dominated ecosystems. Leachate N increased below threshold soil C:N values which were highest in the raised bog and lowest in the upland heath, whilst extractable N was greatest in the upland heath compared to the lowland heath and the raised bog. We therefore conclude that, in addition to soil C:N and the size of C pool, the type of organic matter was an important determinant of N leaching through carbon limitation of the microbial community. Sites with a deeper, microbially active Calluna litter layer, such as upland heaths, leach less nitrogen than Sphagnum rich ombrotrophic bogs.