A Forest Ecosystem Observatory

RENECOFOR is a national network for the long-term monitoring of forest ecosystems. It was created in 1992 by the National Forest Office (ONF) following France’s commitment to an international effort to monitor atmospheric pollution in forests.
RENECOFOR’s mission is to detect possible changes in forest ecosystem processes and to better understand the reasons for these changes. The Network is composed of about a hundred permanent plots where different components of the forest are monitored: trees, soil, atmosphere and plant diversity.
The components of forest ecosystems observed in RENECOFOR network
The components of forest ecosystems observed in RENECOFOR network - ©ONF


Three closely monitored phenomena:

  • Forest ecosystem reactions to a changing climate
  • The forest nutrient balance, in particular under the effect of atmospheric pollutants
  • Changes in plant species diversity.

Why observe forest ecosystems?

Acid rain, climate change, changes in biodiversity: for several decades, a variety of global disturbances have been threatening our environment.

The forest is an important ecosystem in terms of the space it occupies (around 30% of the French territory) and the many services it provides society.

However, the trees' long life cycle makes them particularly vulnerable to changes in environmental conditions (progressive acidification or eutrophication of soils, migrating insect pests...) and to extreme climatic events (droughts, storms...).

With an uncertain future ahead, long-term monitoring is a management tool which will allow us:

  • To detect possible changes in ecosystem processes
  • To better understand the effects of global changes on ecosystems and to be able to predict their outcomes and adapt accordingly.

Acid rain: the trigger

At the beginning of the 1980s, precipitation containing acidic pollutants (also known as "acid rain") was threatening the forests in industrialized countries with a massive and rapid decline. Alarming symptoms, including the yellowing or loss of foliage and even tree mortality, occurred over an unprecedented area throughout the forests of Central Europe.

However, a lack of scientific information made it impossible to evaluate the true extent of the phenomenon or to predict the outcomes of the onslaught.

In retrospect, though the forests did not all die off, the acid rain crisis left its mark on public opinion. People had become aware that human activity had an impact on the environment as a whole, and not just in urban areas. Politicians and governments were moved to sign international agreements to reduce emission levels of atmospheric pollutants and to monitor their impact on the environment.

In this context, several forest monitoring systems were put into place, one of which was RENECOFOR.

How is RENECOFOR designed?

102 sites distributed throughout mainland France

The distribution of the RENECOFOR monitoring sites was designed to include a range of varied ecological contexts. Each site covers a fixed area of two hectares. Site locations were chosen to ensure that the required measurements and sampling campaigns could be carried out while allowing normal forest management activities to be pursued.

The location of the RENECOFOR sites
The location of the RENECOFOR sites - ©Luc Croisé / ONF

A unique approach

RENECOFOR applies an original approach to complement other monitoring systems. This national Network spans the gap between:

  • Broad-scale systems which are statistically representative of the territory but where few parameters are observed
  • Experimental research sites with considerable instrumentation and equipment where ecological processes can be explored in detail, but which are few in number and, therefore, cover only a narrow range of forest contexts.

A rigorous organisation

All measurements are taken so as to ensure comparability from one site to the next over the long term. This strategy requires:

Detailed and coherent procedural protocols, defined internationally

  • Rigorously trained field agents
  • A strict calendar to ensure synchronous measurements among sites
  • Continuous assessment of procedures and their associated uncertainties to ensure improved quality.


As data are collected, they are recorded, checked and saved in a single national data base.

Regular assessments

Team members from the Coordination Centre present their report to the evaluating commission.
Team members from the Coordination Centre present their report to the evaluating commission. - ©Erwin Ulrich / ONF

Since 2006, regular assessments have been carried out to provide an overview of the Network's scientific activities and accomplishments, and to furnish our funding bodies with analyses and suggestions for future orientations.

The first assessment took place in 2006 and the second in 2013.

Following the second assessment, a Scientific Pilot Committee was created. Composed of researchers and representatives from our funding bodies, the Committee follows RENECOFOR activities from year to year and provides expertise and support for the Network's missions.

Pour en savoir plus

Why these observations? Who will benefit?

Flow chart - from data collection to final users and applications
Flow chart - from data collection to final users and applications - ©ONF
  • To inform public policy

The data collected by RENECOFOR helps produce quantitative indicators and establish precious reference points to enlighten public policy both at the national and international levels (for example, to help define European limits for atmospheric pollutants).

  • To enrich research and support education

RENECOFOR observations bring new insights to research and educational institutions to help better understand forest ecosystem processes and how these processes respond to environmental change. The Network's observations:

  • Quantify key ecological parameters and their variations at the national scale;
  • Bring to light trends and changes over time;
  • Provide reference data to test theoretical models in terms of their ability to accurately describe natural phenomena and to forecast future conditions;
  • Provide opportunities for progress in methodology, related to our actual ability to detect changes in our environment.

In addition to carrying out its primary missions, RENECOFOR allows researchers access to our sites and to our extensive collection of samples for a variety of scientific studies.

  •  To inform the public at large

RENECOFOR results are also communicated to the public at large at trade shows and conferences, during on-site visits and though oral presentations.

Pour en savoir plus