Best adapted chestnut trees to new environmental scenario for timber production at the Montseny Natural Park

Castanea sativa Mill., one of Europe’s most durable forest tree species, was intensively managed for timber in north-eastern Catalonia, Spain (Montseny Natural Park and Guilleries) in the 1950s. This production was mainly focused on poles, stakes and barrels. However, these uses were replaced by cheaper new products, causing a species decline in the area with the resulting of forest abandonment and the increase of damage caused by the chestnut blight fungus (Cryphonectria parasitica). Currently, the use of chestnut wood for structures is presented as a revulsive for this sector. Nevertheless, considering the current climatic scenario it is necessary to develop forest reproductive materials (FRM) from trees that are adapted to this potential type of production. The expected environment will be highly stressful from abiotic conditions (long and hot summer droughts with extreme temperatures) and biotic agents, in particular chestnut blight canker. In 2013, we located 9 outstanding chestnut coppice stands in different edaphoclimatic areas of Montseny, and seeds were collected from ‘plus trees’ identified in those plots. In 2014 a field progeny test (243 trees) was planted in a representative area of the Montseny called ‘Fontmartina’. Data of vegetative development, annual growth, leaf phenology, damage caused by biotic agents, canker and gall wasp were recorded during eight consecutive years, 2014-2022. In addition, the susceptibility to the canker was evaluated for each genotype under controlled conditions. At age nine, tree-ring traits (tree-ring, early wood and late wood width, number, size and distribution of the vessels) were analysed to capture environmental adaptation during wood formation in 2022, a dry and hot year. All this information will lead to installing a clonal seed orchard in 2023 with 34 genotypes to get potentially better FRM related to growth habit for wood production and better adaptation to the future environmental scenario of Montseny.