Experimental plantation - Nassiet (40)

The Project

 The experimentation and natural regeneration project covers an area of 5.7 hectares in the south of the Landes region (Nouvelle-Aquitaine), in the 'Collines de l'Adour' sylvo-ecoregion, with the aim of testing the adaptation of Sequoia sempervirens to climate change and its sociability when mixed with other species.

Led by a doctoral student as part of his thesis, who also the plots, it is part of a research consortium for the adaptation of forests in the Landes massif and the Adour piedmont area.

An experimental agreement signed between the project leader at the University of Pau and Pays de l'Adour (UPPA) governs this collaboration, which is based on the scientific expertise of the UPPA and the practical experience of the forester.

The main objective is to evaluate different planting methods (single-species, mixed and enrichment planting in deciduous forests) in order to gain knowledge about the growth, ecological adaptation, disease resistance and impact on biodiversity of Sequoia sempervirens.

Diversification species from natural regeneration and added in enrichment planting are also planned to complete the study:

Block 1: Afforestation of fallow land near the Luy de France river with Sequoia sempervirens, combined with pear trees, Virginia tulip trees and alders. Block 2: Old unmanaged coppice, thinned and cleared, then enriched with Sequoia sempervirens while promoting the natural regeneration of oak, beech and chestnut trees. Block 3: Old pine forest destroyed (1999 storm, 2023 felling), transformed into a mosaic forest: strips of pine, Sequoia sempervirens (natural barriers), and regenerating deciduous trees (pedunculate oak, chestnut).

 

Landes Department

The Collines de l'Adour region is a predominantly agricultural area (80%) of plains and hills, with cool, acidic sedimentary soils. It is characterised by its mixed farming landscapes, fragmented woodlands and dense network of Adour tributaries, which shape floodplains and nagtural environments.

The project is located in an ecological corridor of the wooded sub-network, where ageing and diverse forests represent a conservation challenge. Faced with the degradation of riparian forests and the disruption of biological continuity, it aims to restore the green and blue network in order to maintain the connectivity of habitats and the survival of species.