Experimental set-ups
Guyafor network
Guyafor is a network of permanent forestry plots installed in French Guiana. It is dedicated to the long-term study of forest dynamics and biodiversity.
Objectives
This network, co-managed by research organizations (CIRAD and CNRS) and by the manager of French Guiana’s forests (ONF), is a research platform available to scientists. They benefit both from the data acquired on these forests and from the facilities on site, enabling them to develop their own research themes.
Its main objectives are to understand:
- The structural and floristic organization along environmental gradients
- The long-term forest dynamics of natural and exploited forests by focusing on :
- the roles of demographic processes (regeneration, growth and mortality)
- the carbon cycle of the living above-ground biomass
- the effects of climate change
This observatory of the French Guiana’s forests is a long-term monitoring tool for tropical rainforests. In addition to acquiring knowledge about how these forests function, it can provide the scientific basis for defining sustainable management rules for French Guiana’s forests, and play a role in land-use planning and local sustainable development initiatives.
The study sites
The plots were preferentially installed in the coastline fores but are gradually integrating the forests of the interior of the territory.
The Guyafor network is built from pre-existing permanent sites installed since the 1970s (Bafog, Paracou) and the establishment of new sites since 2000.
Guyafor currently covers 300 hectares of forest in 17 sites.
Paracou and Nouragues are full-fledged research stations with their own functioning. These stations have been hosting scientists since the early 1980s on research topics that go far beyond the scientific framework of Guyafor. Among all the research tools present on these stations, only the forest plots are integrated into the Guyafor network.
The data collected
- Trees census
On each plot, the trees are labelled and numbered, mapped and botanically determined (at least with a vernacular name) and their diameter at breast height is measured at regular intervals (approximately 2 250 000 measurements for more than 240 000 trees (2024)). The tree measurement protocols have been homogenized and standardized between the 3 network partners.
- Botanical identifications
Botanical identifications are made thanks to the IRD Herbarium platform of French Guiana (CAY), as well as by reference to the botanical inventories of the Guyadiv network of the AMAP lab gathered in the checklist published in 2022 by Molino et al. A herbarium collection is also housed on EcoFoG's premises to keep the samples used for botanical determinations. In 2024, this collection consisted of 3270 samples representing some 900 taxa.
- Environment
Climatic, pedological and topographical data are collected to provide a detailed description of the environment at each site. Rain gauges were installed on most of the sites. Soils were described on each site according to the WRB classification and topographical surveys were carried out. This work was carried out under the supervision of V. Freycon (CIRAD) and B. Ferry (AgroParisTech). Ferry (AgroParisTech).
Data Management
All measurements are centralized in a secure database that stores all data, before and after corrections. The data are checked, documented and enriched, and as census campaigns are carried out, they are published in a dedicated Guyafor data repository, along with a data dictionary to ensure that they are used appropriately.
Data management and data availability are covered by a tripartite agreement (CIRAD, CNRS, ONF) and are ensured by EcoFoG. Analysis routines developed with the open-source software R are available to calculate the most common forest structure and dynamics parameters from data in the Guyafor database.