Block neutral models to predict the response of Biodiversity in dendromicrohabitats to Forest Management – BloBiForM

The BloBiForM project aims at developping an array of tools for assessing forest management effects on biodiversity.

We focus on organisms that depend on tree-related microhabitats (TreMs), i.e. small parts of trees with a specific structure that makes them habitat for some species like hollows, cracks etc. We assume that the spatiotemporal availability of TreMs is a key driver for the persistence of associated saproxylic species. Indeed, species living in TreMs must constantly colonize new microhabitats, as the one they already occupy inevitably vanish due to decay or tree harvest. How management take place in space and time could therefore deeply affect those species.

To assess this latter point, BloBiForM proposes to combine two modeling framework: (i) a model of the spatial dynamics of one type of TreM in a managed forest and (ii) a model of the community dynamics within TreMs, based on the metacommunity framework. We will make use of a running example throughout the project: the public forest of Grésigne in the Tarn department, France. There we will consider basal cavities, which are typical TreMs in this area, and associated beetles and fungi.

The core scientific contribution of BloBiForM will be to develop cutting-edge metacommunity models, called block neutral models. This new generation of models will borrow from both the Neutral Theory of Biodiversity and the Niche Theory, and will search for an intermediate way combining the quality of these two classic theoretical frameworks: parsimony and realism, respectively. We will combine these conceptual developments with data acquisition through innovative application of environmental DNA methods on cavity wood mould, which will lead to a realistic calibration of our metacommunity models.

Calibrated models developed in BloBiForM will contribute to assessing how local management practices affect the biodiversity associated to basal cavities, using simulation approaches. We will explore various scenarios about the evolution of the national strategy for public forest management, and various ways of implementing these scenarios locally in Grésigne. The project will shed light on the relative importance of these two levels for the conservation of biodiversity.

Although BloBiForM focuses the Grésigne forest as a case study, the outcome of the project will be a general and transferrable methodology, which can be used to unravel conservation implications of management strategies at forest scale in a broad range of contexts. It will thus contribute to the development of ecologically grounded approaches for studying trade-offs between wood production and biodiversity conservation in managed forests.