Tribute to Sylvie Gourlet-Fleury

Sylvie was seconded to CIRAD by the French Ministry of Agriculture and Food in 1989. Through her research, she made an exceptional contribution to the understanding of the functioning of tropical rainforests, particularly in French Guiana and in the forests of Central Africa. She has thus greatly contributed to the development of the concept of sustainable management of these ecosystems, which are reservoirs of biodiversity and are now at the heart of multiple issues in the face of the climate emergency. Tropical forests were alive in her: even if she knew that their use by human societies was inevitable, it was always the protection and survival of these forests that were close to her heart.

After completing her training as a rural engineering, water and forestry engineer (ENGREF) in 1986 with a final internship in Burundi (mapping the forest vegetation of the Zaire-Nile ridge), Sylvie joined the ENGREF centre in Montpellier (now AgroParisTech) as assistant to the director of higher forestry training for hot regions. In this capacity, she trained and supervised numerous students from the North and South during field modules in France and Cameroon. She also carried out a first expertise on the forest vegetation of Mount Oku and the Dja reserve in Cameroon.

In 1988, Sylvie took up a position as a forestry expert in the BDPA-SCETAGRI research office. She was responsible for mapping and typology of forest vegetation in France, Guinea Conakry, Burundi and Rwanda. This was an opportunity for her to perfect her photo-interpretation skills and to learn how to process satellite images (SPOT). Moving from characterising forest communities to understanding how they function quickly became a priority for her, and the position in French Guiana offered to her by the Centre Technique Forestier Tropical (CTFT) in 1989 was an opportunity to make the leap from expertise to research. Since then, she has never left CIRAD.

In French Guiana, Sylvie initially fulfilled a dual role as manager of the Forestry Department's IT equipment and as co-manager of the recent experimental forestry scheme at Paracou. Faced with the need to analyse large data sets, Sylvie decided to undertake a research career: she enrolled at the University of Lyon, first in a DEA (1992-1993, Analysis and Modelling of Biological Systems, directed by J-M Legay) and then in a thesis, under the direction of François Houllier (1994-1997). His DEA and thesis work focused largely on the study and understanding of the determinants of tree growth in natural forests and the reaction of these trees to silvicultural interventions. They lead to the recommendation of new silviculture rules and the revision of the duration of rotation cycles in Guyanese forests. Her work led to the construction of a forest dynamics simulator, SELVA, based on a distance-dependent tree model. Sylvie was undoubtedly one of the pioneers in the modelling of tropical forest dynamics.

In June 1996, Sylvie was posted to Montpellier and attached to the Natural Forests Programme in order to finish writing her thesis, which she defended in 1997. From 1996 to 2002, she continued to manage the system, the teams and the work in Paracou from a distance. In the meantime, from 1998 onwards, she was involved in setting up a research team focused on modelling the dynamics of natural forests and on improving our knowledge of forest regeneration processes, which was at the time a stumbling block in attempts to predict the medium- and long-term effects of forest exploitation. In 1999, she took charge of the "Study and modelling of forest dynamics" team within the CIRAD-Forest Natural Forest Programme. From 1999 to 2004, in parallel with various project set-up and management activities, student supervision and article writing, she was involved in the development of a unit scientific project. The unit that was created was the second CIRAD unit to successfully take part in the international external evaluation set up by the management in 2004. This led to the creation of the Natural Forest Dynamics Unit, which was headed until 2010 by Sylvie, one of CIRAD's first female UR directors. In 2009, a new restructuring of CIRAD's units prompted Sylvie, in collaboration with Alain Billand, then head of UR 36 'Forest Resources and Public Policies', to merge the two units with the 'Forests and Biodiversity' UR in Madagascar to create the BSEF unit (Tropical Forest Ecosystem Goods and Services), which became Forests and Societies in 2015. Sylvie will ensure a transition period by remaining co-leader of one of the areas of the new unit.

From 2011 onwards, Sylvie has been involved in setting up and coordinating several large-scale research projects in the Congo Basin (Coforchange, DynafFor, Dynafac, P3FAC). She is constantly working to find funding to perpetuate the MBaiki system in CAR and to ensure regular inventory measurements, sometimes even risking her life. Without her determination and strength of conviction, this system would not be one of the oldest systems still active in the tropics today, along with Paracou. All his projects have the same objective of guaranteeing the sustainability of forest stands. In Central Africa, these projects will lead to the emergence of one of the largest networks of forest dynamics monitoring systems in Central Africa based on an original concept, and to the creation of an irreplaceable database on the composition and structure of dense rainforests. These data will feed numerous research projects, including most recently an international study on the composition and vulnerability of Central African forests, which she coordinated in partnership with the IRD and which will be published in the journal Nature in 2021. This study mapped the composition of the tropical forests of Central Africa and their vulnerability to the increased climatic and human pressures expected in the coming decades.

A tireless worker, full of communicative energy, straightforward and direct in both her thinking and her life, Sylvie has divided her time between difficult fieldwork in the forests of Guyana and the Congo Basin and in-depth analyses of tree population dynamics. Her work is rightly considered fundamental to understanding the ecological mechanisms that determine the very nature of tropical forests. Highly regarded and respected by the scientific community, Sylvie was a tireless promoter of new projects to better understand the interactions between forest ecology, forest management and the impacts of climate change. In addition to her great professional skills, her human qualities, her helpfulness, her friendliness, her inquisitiveness, her ability to listen and her great tenacity in the face of difficulties of all kinds made her an exceptional colleague appreciated by all. Each and every one of her colleagues will remember her as a lucid person who, right up to her last days, never gave up, never gave in to despondency, was sometimes sorry about the course of the world and human improvidence, but kept within herself an invincible strength of hope, which was evident in her eyes. An exceptional woman, she will remain a model for all young women researchers at CIRAD who may sometimes doubt their real possibility of making progress and asserting their point of view.

Her dynamism was contagious and Sylvie knew how to involve and motivate her colleagues as well as numerous students from the North and South who have now become essential partners in scientific work in Central Africa.
Her publications (more than 200 articles, book chapters and technical papers) and conferences demonstrate the importance of her contribution to the ecology and management of Central African tropical forests. Sylvie leaves a huge gap in the scientific community of tropical forest ecologists and, in her memory, all her colleagues interested in tropical forests will continue her fight for more than 30 years for the conservation of the tropical forests of Central Africa and the world in general.

The funeral will take place on Friday 27 January, at the Pompes funèbres Aliaga, 111 route de Prades, in Saint Gely du Fesc, at 11.00 am. Sylvie did not want flowers or wreaths. A book of memories is available at Forêts et Sociétés, in which anyone wishing to leave a last message or testimony can do so. For expatriate colleagues and our international partners, it is possible to send an e-mail message or a photo to Plinio Sist, which will be inserted in the booklet.