Integrated Monitoring (ICP IM)

The International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM).

About us

Integrated Monitoring (ICP IM) is an effect-oriented multi-disciplinary environmental monitoring programme to assess effects on ecosystems from air pollution, under the Convention on Long-range Transboundary Air Pollution (CLRTAP). The programme conducts long-term simultaneous measurements of physical, chemical, and biological properties at permanent monitoring sites with catchment budgets and fluxes as one main aim. The ICP IM sites are mainly forested catchments located in natural or semi-natural areas.

The programme belongs to a group of six specialist ICPs which have been set up under the CLRTAP Working Group on Effects (WGE) to examine relevant receptors and environmental issues.

From 2022, ICP IM is extending the programme to include less intensive long-term monitoring at a greater number of sites, in a wider variety of ecosystems. We are inviting new and existing sites to become part of the IM programme, utilise our monitoring protocols and contribute to the international database.

The overall aim of integrated monitoring is to establish consistent time series of environmental variables at a number of well-studied sites. Implementation of the Programme provides a major contribution to the international data requirements for examining the ecosystem impacts of climatic change, changes in biodiversity and depletion of stratospheric ozone. A primary concern is the provision of scientific and statistically reliable data that can be used in modelling and decision making rather than establishing representative surveys across the UNECE region.

ICP IM was originally to determine and predict the state and change of terrestrial and freshwater ecosystems in a long-term perspective with respect to the impact of air pollutants, especially nitrogen and sulphur. This was to provide a basis for decisions on emission controls and assessment of the ecological impact of such controls within the UNECE CLRTAP. Full implementation of the IM Programme allows the ecological effects of inter alia tropospheric ozone, heavy metals and persistent organic substances to be determined.

The aims are fulfilled by:

monitoring both biogeochemical trends and biological responses in small (10 - 1000 ha) clearly defined catchments,
seeking to separate the noise of natural variation, including succession, from the signal of anthropogenic disturbance by monitoring natural or semi-natural ecosystems,
developing and applying tools, e.g. models, for regional assessment and prediction of long-term effects.

Implementation of the IM Programme by individual countries will fulfil many of the obligations of those countries to undertake impact studies. Not only under the Convention on Long-range Transboundary Air Pollution, but for example also under the Convention on Climate Change and the Convention on Biological Diversity, and the EU National Emission Ceiling Directive.

We are welcoming new and existing parties to join the extended ICP IM monitoring programme.

ICP Integrated Monitoring has decided to develop its monitoring strategy to include other ecosystem types than forests. The new ICP IM monitoring strategy aims at understanding the effects of air pollution on biodiversity in ecosystem types that are underrepresented in the Air Convention. The new monitoring strategy has also been simplified with different levels of monitoring intensity.

The extended monitoring strategy aims at monitoring current and future effects of air pollution on ecosystems across the UNECE area. The extended ICP IM monitoring programme is developed to facilitate multiple purposes of ecosystem reporting such as the EU – NECD and habitat directive.

The extended monitoring program has been developed with three levels of monitoring in ecosystem types other than forests such as grasslands, heathlands, wetlands, or coastal habitats:

Level 1: Full ICP IM site (monthly measurements, catchment as stated in the ICP IM Manual)
Level 2: Plot scale with element budgets on other ecosystem types (monthly measurements)
Level 3: Plot scale without element budgets (aiming for annual measurements, but accepting other temporal resolution) of soil and vegetation (plant list and abundance, soil and foliage chemistry)

The extended ICP IM monitoring programme will ensure that other ecosystems that are not part of the monitoring of the Air Convention today are monitored with proper methods that provide consistent monitoring within the UNECE area. The extended ICP IM monitoring programme is designed in a way that allows parties to be part of the ICP IM monitoring programme based on their own prerequisites with less intensive monitoring campaigns compared with the current ICP IM monitoring.

The convention is a framework that brings together science and policy to deal with air pollution, launched in 1979. It is a successful example of what can be achieved through intergovernmental cooperation.

When air pollutants from thousands of kilometres away were found to damage entire ecosystems, international cooperation was needed to mitigate the effects. The United Nations Economic Commission for Europe (UNECE) gathered European countries to cooperate to reduce air pollution. It resulted in the Convention on Long-range Transboundary Air Pollution (CLTRAP) in 1979. This treaty was the first of its kind and has laid the foundation of a very successful framework. Over the years, the number of substances covered by the Convention and its protocols has been gradually extended. Today it also covers ground-level ozone, persistent organic pollutants, heavy metals, and particulate matter.

The Convention has substantially contributed to the development of international environmental law. It has created a much-needed framework for controlling and reducing the damage to human health and the environment caused by transboundary air pollution.

Links

United Nations Economic Commission for Europe website on LTRAP and its achievements

United Nations Economic Commission for Europe website on Environment Policy about Air

The ICP IM holds annual Task Force meetings, usually together with ICP Waters. The meetings cover recent findings, plans for the future, and formal desicions. The meetings are for invited persons only, but the meeting minutes are available here on this web page in a pdf-format.

Previous meetings

List of meetings and minutes and presentations from the most recent ones.

For presentations and minutes of the joint meeting with ICP Waters please see the ICP Waters site.

Task Force meetings

Meeting minutes for the ICP Integrated Monitoring Task Force meetings 2017-2026 are availalble here (click on the zip file).

The 34th ICP IM Task Force Meeting was held 5-7 May 2026 in Windemere, U.K.
The 33rd ICP IM Task Force Meeting was held 23-25 April 2024 in Dessau, Germany.
The 32nd ICP IM Task Force Meeting was held 28-30 May 2024 in Prague, The Czech Republic.
The 31st ICP IM Task Force meeting was held on 9-11th May in Lunz, Austria.
The 30th ICP IM Task Force Meeting was held held on 10-12th May in Miraflores de la Sierra, Spain.
The 29th ICP IM Task Force meeting was organised as an online meeting, 13-14 April 2021.
The 28th ICP IM Task Force meeting was organised as an online meeting, 13-14 May 2020.
The 27th ICP IM Task Force meeting was held together with ICP Waters in Helsinki, Finland 4-6 June 2019.
The 26th ICP IM Task Force meeting jointly with ICP Waters was held in Warsaw, Poland, 7-9 May 2018.
The 25th ICP IM Task Force meeting together with ICP Waters was held in Uppsala, Sweden, 9-11 May 2017.

The ICP IM publications are presented here. The page contains a list of recent scientific publications, ICP IM Annual Reports, and a pdf with information on all other, older ICP IM publications.

Recent publications

Weldon, J., Aas, W., Albiniak, B. et al. (2026). A long-term ecosystem monitoring dataset from the ICP Integrated Monitoring network: biogeochemical data from 1977–2020 across 14 European countries. Sci Data 13, 589. https://doi.org/10.1038/s41597-026-07181-8

Lu, Y., Eisenhauer, N., Patoine, G. et al. (2026). Landscape effects on global soil pathogenic fungal diversity across spatial scales. Nat Commun 17, 1164 (2026). https://doi.org/10.1038/s41467-025-67929-5

Weldon, J. (2024).  Modelling forest biodiversity and recovery from acidification.  (Rapport, Institutionen för vatten och miljö:2). Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences.

Futter, M.N., Dirnböck, T., Forsius, M. et al. (2023). Leveraging research infrastructure co-location to evaluate constraints on terrestrial carbon cycling in northern European forests. Ambio 52, 1819–1831. https://doi.org/10.1007/s13280-023-01930-4

Weldon, J., Merder, J., Ferretti, M. et al. (2022). Nitrogen deposition causes eutrophication in bryophyte communities in central and northern European forests. Annals of Forest Science 79, 24. https://doi.org/10.1186/s13595-022-01148-6