Dynafor au colloque ESP-Europe (Ecosystem services partnership) de Tartu

Participation à distance au colloque européen qui rassemblait près de 250 participants, avec une communication et un poster:

Forest for biomass or for biodiversity: scenarii for solving conflicts in the french context

Deconchat, M 1; Malafosse, F 2; Clément-Kumar, F 1

1 Dynafor, INRAE, Université de Toulouse, Toulouse, France

2 Solagro, Voie du Toec, Toulouse, France

Forests are at the center of many of the issues involved in coping with global changes. On the one hand it seems necessary to exploit them more intensively to produce biomass to replace products with a strong impact on the climate, on the other hand it seems necessary to preserve them much more in order to protect the large part of biodiversity they host as well as their role as carbon sinks. The tension between these two seemingly contradictory expectations is the subject of intense debates, which is particularly lively at present in France. Based on the same data, but with different hypotheses, several scenarios have attempted to assess the consequences of the two orientations. Their results are not clearly enough contrasted to favour one scenario in particular. To overcome this difficulty, we believe that 3 new dimensions should be introduced into the analyses. 1) the territorial dimension to better consider local specificities (resources, demands and constraints); 2) the risk dimension to consider the impacts of global changes and the weight of risks in investment options, especially in the very long term; 3) the social dimension to promote better shared collective decision-making conducive to better environmental justice inclusive of a diversity of actors. The presentation defines these 3 dimensions and what they imply in prospective approaches

Edge paradox : forest edges as a threat and an opportunity for biodiversity and ecosystem services

Deconchat, M ; Barbaro, L ; Andrieu, E

Forest edges are sometimes presented in the scientific literature as one of the causes of the degradation of biodiversity, linked to the fragmentation of forest areas, and sometimes presented as species-rich habitats. This apparent paradox makes it difficult to define land management strategies that are favourable to the preservation of biodiversity and the associated ecosystem services. An analysis of the literature on the subject shows that this paradox is the result of confusion between several ecological effects improperly grouped together under the same expression "edge effect". Fragmentation-related edge effects concern the level of habitat fragments and their species composition, whereas local edge effects concern portions of edges at a much finer spatial scale. Moreover, these effects are not expressed at the same moments in the spatial dynamics of edges. Fragmentation edge effects concern the consequences of a change in the characteristics of forest areas, and thus the appearance of edges, whereas local edge effects concern edges that are already in place. This analysis therefore shows that the creation of new edges through fragmentation is often the cause of a degradation of biodiversity at the level of woodland fragments, whereas existing edges, after a certain period of time, may harbour a locally rich biodiversity. This analysis should lead to a more precise definition of edge effects in order to reduce confusion.