Suitability of close-to-nature silviculture for adapting temperate European forests to climate change

In many parts of Europe, close-to-nature silviculture (CNS) has been widely advocated as being the best approach for managing forests to cope with future climate change. In this review, we identify and evaluate six principles for enhancing the adaptive capacity of European temperate forests in a changing climate: (1) increase tree species richness, (2) increase structural diversity, (3) maintain and increase genetic variation within tree species, (4) increase resistance of individual trees to biotic and abiotic stress, (5) replace high-risk stands and (6) keep average growing stocks low. We use these principles to examine how three CNS systems (single-tree selection, group selection and shelterwood) serve adaptation strategies. Many attributes of CNS can increase the adaptive capacity of European temperate forests to a changing climate. CNS promotes structural diversity and tree resistance to stressors, and growing stocks can be kept at low levels. However, some deficiencies exist in relation to the adaptation principles of increasing tree species richness, maintaining and increasing genetic variation, and replacing high-risk stands. To address these shortcomings, CNS should make increased use of a range of regeneration methods, in order to promote light-demanding tree species, non-native species and non-local provenances.