Title: The effect of elevated N deposition on nutrient cycling in raised bogs

Primary Researcher: Juul Limpens
Email address: Juul.Limpens@wur.nl
Submitted on: July 9, 2002

Start date: 01 May 1998
End date: 01 May 2002

Introduction:

Atmospheric deposition of nitrogen (N) compounds is strongly elevated in the Netherlands. For raised bogs the critical load is exceeded almost tenfold.
As peat-forming processes occur mainly in nutrient poor environments, the question is raised whether restoration and development of raised bogs is possible under the high ambient deposition levels.

Aim:

To quantify the effect of elevated N deposition on nutrient cycling in raised bogs.

Research:

The research is focused on the effect of N compounds on growth, development, and litter decomposition of ''Sphagnum'' as well as competing vascular plants (for example ''Betula'' and ''Molinia'')

Fertilisation experiments with N and/or P are carried out at 6 sites (NL&IR) which differ in ambient deposition levels and/or vegetation type. Both changes in species composition and water chemistry are followed. Rates of decay of ''Sphagnum'' material with different tissue N concentrations are followed at 3 sites (NL). Some extra attention is given to species replacement of bryophytes in fertilisation experiments and the concomitant ecosystem effects. Greenhouse experiments are carried out to clarify some interactions between vascular plants and bryophytes.

Future Research

Research topics could be separating the effects of water table fluctuations and N deposition on species composition in raised bogs and studying the effects of N deposition on phenolic compounds in ''Sphagnum''.

External Funding Sponsors

Ministry of Agriculture, Nature Management and Fisheries