An overview of the 2017 report of the French academy of Sciences on biodiversity

In the present context of concerns for biodiversity, the French Academy of Sciences produced in 2017 a report entitled “Mechanisms of adaptation of biodiversity to climate change and their limits”. We briefly review here the production process and structure of the report, and summarize its conclusions and recommendations. The conclusions emphasize the role of habitat fragmentation in the expected impact of climate change on biodiversity, in particular for organisms with limited dispersal abilities, and the disparities in species responses which must be taken to understand the future of species assemblages (“communities”) under different scenarios of climate change. The recommendations cover the organization of biodiversity research and monitoring (development of observatories, key role of embedded time scales and modeling, integration of Human and Social Sciences), as well as critical domains such as Human, animal and plant health, agriculture and forestry policies, and management of the environment.


INTRODUCTION
In the present context of concerns for biodiversity, the French Academy of Sciences produced in 2017 a report entitled "Mechanisms of adaptation of biodiversity to climate change and their limits". The purpose of this paper is to briefly review the production process and structure of the report, and to summarize its conclusions and recommendations, as presented by one of the authors (JDl) at the Brazil-French Symposium on biodiversity held in Manaus (Amazonas, Brazil) from June 2 to 5 2018. The full version of the report is available (in French) at http://www.academie-sciences.fr/fr/ Rapports-ouvrages-avis-et-recommandations-del-Academie/mecanismes-adaptation-biodiversiteaux-changements-climatiques.html.
The decision of producing this report obviously stemmed from the current concerns for environmental change. Current environmental issues are dominated by two major phenomena, both resulting from human activities: the ongoing and forecasted climate change (IPCC 2014) and the worldwide erosion and homogenization of biodiversity (Cardinale et al. 2012). The two phenomena have been analyzed for decades (Diaz et al. 2006, Stern, 2007 and have been now recognized as strongly linked (e.g., Bellard et al. 2012, Bálint et al. 2011, Oliver and Morcroft 2014. The adaptability of the living world to environmental changes raise a number of questions. The need of anticipating as much as possible the consequences on human societies of global change as a whole lead the Academy to develop this report to gather information and provide a point of view complementary to most available reports on global change. This is why this report is primarily focused on the adaptability of biodiversity to climate change. While much is known, as the report shows, the list of open questions (e.g., role of extreme climatic events, degree of resilience of a variety of ecological processes, complex interactions, predictability of ecological systems…) is large, and a special attention was put on the uncertainties of the various mechanisms and issues reviewed.

PRODUCTION OF THE REPORT
The production of the report was coordinated by Sandra lavorel, Jean-Dominique lebreton and Yvon le Maho, members of the French Academy of Sciences.
A preliminary draft was first assembled and revised in a series of meetings of the environment Committee, a permanent committee of the Academy, which gathers in a strongly pluridisciplinary way a variety of scientists and scientific fields implied in environmental science: ecology, Climatology, Biology, earth sciences, Chemistry, Paleontology, Physics, Hydrology, etc.
This first draft was then polished by a subcommittee, who met on January 17, 2017, and submitted for approbation to the environment Committee.
The resulting version was amended and approved by vote by the whole Academy on June 27, 2017, and made available online in September 2017.

STRUCTURe OF THe RePORT
The report consists of 15 pages covering a general overview of the subject, conclusions, and recommendations, reviewed below, accompanied by 26 thematic sheets on specific topics.
These 26 thematic sheets review mechanisms underlying the degree of adaptability of biodiversity to climate change. They were prepared by 33 leading French experts. The 17 first sheets deal with mechanisms of adaptability at various levels of organization: individuals (6), populations (4), ecosystems (7). The 9 other sheets cover the interface between biodiversity and human societies: mitigation (2), exploitation and management (5) and social adaptation (2). They were prepared under a common format (3-7 pages, 1 or 2 figures, 1 example) and layout (Description of the mechanism of topic, limits and solutions, uncertainties). Based on such expertise, these thematic sheets constitute a rich and homogeneous source of information on biodiversity in face of climate change, to be used in the future. Their full list is given in Box 1.

SUMMARY OF THe RePORT CONClUSIONS
The main conclusions of the report are based on the fact that, among ecological mechanisms, "the dominant phenomenon induced by an increase in temperature is the shift towards the poles or higher elevations of the area occupied by each animal of plant species". From this basic statement, stem the following conclusions: • It is important to consider the capacities of adaptation of living organisms when they cannot move, in particular under the effect of landscape fragmentation. • The individual adaptability through plasticity (…) and genetic adaptation (…) strongly vary among organisms. • The expected diversity of the response of species to the various parameters of climate change induces disparities in the response of communities (species assemblages). • Such disparities are already well documented, and taking them into account is absolutely needed to understand the future of species assemblages under different scenarios of climate change

RECOMMENDATIONS
The recommendations in the report were organized under 7 headings, ranging from issues dealing with the acquisition and dissemination of scientific knowledge on the effects of climate change through its consequences for biodiversity (the first 4 recommendations), to broader issues dealing with the consequences for human societies and priorities for adaptation to climate change and potential mitigation. While these recommendations were developed with specific reference to the French context, they are of general interest, would it be only for the responsibility of France towards intertropical biodiversity in overseas departments and territories (see rec. 7), among which what deals with biodiversity in French guyana is obviously of special interest to Brazil. What follows is an abridged literal translation of the report recommendations.