Initially, the promoters of the Paracou experimental site sought to answer two main questions.
- What are the possibilities of recovering the commercial standing volume in logged forests of the coastal part of French Guiana?
- Is it possible to stimulate this recovery with appropriate silvicultural techniques and rules, easy to apply on a wide scale, in order to achieve sustainable production in these forests?
These two questions influenced the design of the disturbance operations, which were set up as a silvicultural experiment testing three levels of intensity of logging and thinning, associated with a control modality. More than 125 hectares of trees ≥ 10 cm diameter at breast height (DBH) were spatialised and monitored inside 16 large plots, of which 75 ha have been followed yearly since 1984 and 50 ha since 1991. The first results were used directly by the Office National des Forêts (the French Forest Service) to establish management rules in the permanent forest estate and to orient further silvicultural trials in managed forests.
Although the initial objectives were not forgotten, additional research projects were initiated at the Paracou site as the experiment progressed, widening the scientific scope to include issues of ecological modeling, functional ecology, biodiversity and ecosystem sciences in the global change context. This was due mainly to the advantages of the Paracou research site for forest ecologists. The experimental design, consisting of different disturbances of very-well known intensity and fully documented, provides potential for a large range of ecological research on ecosystem resilience. The long-term spatialised data set collected on the stands offers an excellent background for developing targeted studies. The plots are geo-referenced, which allows superposition of ground measurements with remote sensing data. Finally, the facilities at the site contribute to good working conditions for researchers: local shelters, easy access, proximity of the town of Kourou and its forest research centre, and permanent staff with a sound knowledge of the site. In 2004, a CO2 flux tower Guyaflux was set up by INRA to determine the ecosystem carbon source or sink strengths. The eddy covariance system allows continued monitoring to analyze the impact of changing climate to ecosystem carbon balance.
All together, these conditions gave rise to an opportunistic development of multidisciplinary research at the site, and led its managers to reformulate its scientific outlook towards the study of the effects of global changes (climate as well as land-use changes) on the functioning and long-term dynamics of tropical forest ecosystems.
A few numbers on the exceptional data sets collected in Paracou
- 125 ha of tropical forests
- 16 permanent forest plots with 9 on a disturbance gradient
- more than 70 000 trees
- more than 1 800 000 DBH measures
- more than 700 tree species
- 32 full forest censuses from 1984 up today
- over 100 scientific publications per year