PURPOSE

The aim of the Conference is to present the state of the art and to critically review the methodologies applied so far for calculating critical loads for acidification and eutrophication. The presentation and discussion of recent advances in the field of biological responses to acidification and eutrophication should strengthen the relationship between calculated exceedances and the observed biological and ecological effects in the field. The purpose is to reach beyond empirical experiences – how can we assess changes in ecosystem structure, composition and function, and how is that related to calculated exceedances.

TOPICS ADDRESSED AT THE CONFERENCE

Focus will be on the links between chemical pollution of air, water and soil, and ecological indicators of damage. These topics include the complex relationships between

• soil water chemistry
• vegetation chemistry (C/N, N/P-ratios)
• litter chemistry
• nutrient turnover
• ecosystem status.

Other topics will be the application of data from laboratory experiments, field experiments and large-scale statistical surveys of ecosystem changes in setting critical loads. A special session will be devoted to critical loads for freshwater.

SCIENTIFIC COMMITTEE

Dr. Roland Bobbink, Utrecht University, The Netherlands
Prof. Keith Bull, Institute of Terrestrial Ecology, UK
Dr. Heinz D. Gregor, Federal Environmental Agency, Germany
Dr. Peringe Grennfelt, Swedish Environmental Research Institute, Sweden
Prof. Peter Högberg, Swedish Univ. of Agricultural Sciences, Sweden
Prof. Hannu Ilvesniemi, Univ. of Helsinki, Finland
Prof. Jørgen Bo Larsen, Royal Veterinary and Agricultural University, Denmark
Dr. Hans Løkke, National Environmental Research Institute, Denmark
Prof. Egbert Matzner, Bayreuth University, Germany
Prof. Harald Sverdrup, Lund University, Sweden

PROGRAMME

CHARACTER AND OUTPUTS OF THE CONFERENCE

The Conference will have plenary sessions with keynote speaker presentations on selected topics, followed by at least five parallel workshops with a limited number of voluntary papers for oral presentation and posters. The workshops deal with selected topics. Following in depth discussions, the workshops will formulate draft conclusions and recommendations for future activities within the UN-ECE Convention. A synoptic report from the Conference will be made by the Scientific Committee and the Chairmen. The Conference report will be published by the Nordic Council of Ministers.It is proposed that the main themes for the workshops will be addressed by inter-disciplinary approaches through the following topics.

Workshop 1: CRITERIA
How to relate/select criteria to ecosystem state and change

Why basecation/aluminium ratio=1 as the only criterias used in calculation of critical loads?
Are we happy about the present choice of criteria - or are there alternatives?
Should different criteria be chosen for different species or ecosystems?

Chairman: Ursula Falkengren-Grerup

Workshop 2: METHODS
Relations between soil water chemistry, plant chemistry and ecosystem status

The present calculation of critical load deals with a steady state situation which may be reached in a few hundred years.
Do we need “short-term” critical loads with a much more narrower time-horizon (from 100 of years to decades)?
Could the base saturation or the N-status of an ecosystem be used?
On a European scale, do we have sufficient data for dynamic modelling which can cope with time-lags?

This workshop should also discuss uncertainties in the present method – both calculation uncertainties and quality of the data.
If this workshop becomes too large it could be divided into two:
1) Mapping which includes spatial variations and uncertainties in the calculation of exceedances.
2) Plot-scale including uncertainties in field methods on research and monitoring stations.

Chairman: Michael Starr

Workshop 3: ECOLOGICAL INDICATORS
Key ecosystem elements for ecosystem structure and function
(e.g. mycorrhiza associations, immobilisation, resource competition, vegetation competition, soil-fauna changes)

Do we have organisms with good causality with atmospheric deposition? If so - does it mean anything to the system we want to protect (e.g. a disappearance of a lichen/fungi in a deposition gradient may not be relevant for production of trees).
Do we have processes with good causality with atmospheric deposition? If so - does it mean anything to the system we want to protect?

Chairman: Roland Bobbink

Workshop 4: VALIDATION
Relations between statistical large-scale field data and modelled critical loads

Is there any connection between exceedances of critical loads and empirical effects in the field?

This workshop could present a status and the perspectives for the presently used dynamic models. Extrapolation of results from laboratory to the field and to critical load assessments. Where do we have sufficient knowledge/data to extrapolate from laboratory and field, and to what extend do they support each other.

Chairman: Mike Hornung

Workshop 5: FRESHWATER CRITICAL LOADS
Link between catchment characteristics and surface waters, lake sensitivity

Should the F-factor be a flux variable or a concentration variable?

Chariman: Brit Lisa Skjelkvåle

POSTERS AND PRESENTATIONS

Possibilities of publishing contributions in a special issue of a scientific paper will be considered. Further information will be made available on the Conference web site.

EXTENDED ABSTRACTS

A background document will be produced by the organizers including abstracts of presentations and posters, and discussion topics for the workshops. This information will be available at the Conference web site.

Download Abstracts in PDF-format (90 pages/1.17 Mb):      

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