GIS Coop

The GIS Coop is a French scientific public body group called the "Cooperative of data on forest stand growth", whose purpose is to collect and share scientific data on forest stand growth for the development of growth models and management tools. This objective requires installing, monitoring and measuring multiple local networks of permanent plots according to standardised protocols to best cover the full range of variability in growing conditions (climate, site conditions, silviculture, genetic levels). Since the creation of the GIS Coop in 1994, 6 partners (AgroParisTech, CNPF-IDF, CPFA, FCBA, INRAE, ONF) have received support from the Ministry in Charge of Forestry to develop and manage these networks. Seven silvicultural systems for important commercial species in France (even-aged stands of Douglas fir, sessile and pedunculate oak, corsican and maritime pines; mixed stands of sessile oak and Silver fir) are being studied. Each network is composed of experimental sites set up in such a way as to explore the full diversity of ecological contexts (climate, site conditions) of current production areas, and to anticipate their evolution. The strategy of the experimental sites has recently been revised in order to include stratified sampling designs with environmental gradients and to adapt the networks to the new problems posed by global changes. One main focus is mandatory at each site: changes in stand density over time. A wide range of situations are considered, from maximum competition between trees (self-thinning) to free growth without competition. Highly contrasting scenarios of changes in competition are described quantitatively and this requires long-term monitoring. This first main factor is crossed with secondary factors related to silvicultural treatments in the individual sub-networks: the level of genetic improvement and crop intensification (maritime pine), thinning (Laricio pine), and composition/structure (heterogeneous forests). Each site therefore includes at least three plots subjected to these different silvicultural treatments. At each site, diversity of silvicultural treatment is favoured over repetition of treatments (which occurs among sites). A special focus is placed on the earliest establishment stages (planting, first release or thinning). New plots are planted regularly to stagger installation dates and thus decorrelate the effects of age and date on growth, to gradually complete the networks and to renew harvested or destroyed sites. A total of 185 sites (22 oaks, 31 Douglas fir, 14 pine, 114 maritime pine and 4 mixed stands) for 1206 plots have been installed over the past 20 years. The GIS Coop networks provide support for multidisciplinary work in various fields (ecology, ecophysiology, soil sciences, etc.).