Etienne LALECHÈRE, EDYSAN, UMR CNRS 7058, Université de Picardie Jules Verne, Amiens, France, France
Jean-Matthieu MONNET, Univ. Grenoble Alpes, INRAE, LESSEM, France
Laurent BERGÈS, Univ. Grenoble Alpes, INRAE, LESSEM, France
Marc FUHR, Univ. Grenoble Alpes, INRAE, LESSEM, France
Aim
Building a network of interconnected overmature forests is crucial to provide habitat and promote dispersal of a multitude of species that depend on forest structural maturity attributes such as very large living trees and deadwood. In this study, we investigated the potential of Airborne Laser Scanning to identify overmature forests that most contribute to connectivity and that could be integrated into a network of forest protected areas.
Methods
We first characterized the structural maturity of field plots (from 15 m to 20 m) in the French northern Pre-Alps using an index of maturity (IMAT) that combines forest structural maturity attributes. We then selected topographic and LiDAR metrics and used them to calibrate a random forest model to predict the IMAT measured on field plots. Model performance was evaluated with the root mean square error of prediction and a Spearman correlation coefficient. We then used the model to predict the IMAT and overmature forest locations over an area located in the French northern Pre-Alps (652 km²). Using the probability of connectivity (PC) index, we modelled overmature forest stand connectivity considering different species dispersal distances.
Results
We obtained a not negligible RMSEP (0.6) but a high correlation (0.88) between observed and predicted IMAT values which indicates an accurate ranking of field plots. Spatial prediction of the IMAT allowed the distinction between the most and the least mature forests. The PC index indicated key overmature forests that most contribute to equivalent connectivity.
Main conclusions
An innovative modelling framework that binds remote sensing and ecological connectivity models allowed us to locate overmature forests and evaluate their contribution to the connectivity of the whole overmature forest network. This framework prioritized key overmature forest stands to protect or restore in order to maintain connectivity for species that depends on several forest maturity attributes.
Mots clés : Ecological indicators |LiDAR technology |Forest management |Biological conservation |Landscape connectivity
A103864EL