Implementing genetic indicator metrics in a monitoring study of five woody perennial angiosperms and conifers

The conservation of biodiversity ultimately depends on the conservation of its cornerstone, genetic diversity. The central dogma of conservation genetics postulates that genetic variability is beneficial, hence worth preserving to the greatest extent, while the increase of genetic variance enhances the probability of population survival. The genetic indicators proposed by the Post-2020 Kunming-Montreal Global Biodiversity Framework need complementary approaches for a full assessment of adaptive potential. Comprehensive genetic monitoring assesses the state of the maintenance of genetic variation in natural populations and the success of gene conservation actions. Genetic monitoring, the quantification of temporal changes in population genetic variation and structure, elucidates processes that maintain genetic variation and adaptive potential in natural populations, introduces prognosis and helps define tools for the management of genetic resources. Herein, we present genetic monitoring results focusing on south-eastern marginal populations of three perennial woody angiosperms and two conifers, namely chestnut (Castanea sativa), sessile oak (Quercus petraea), pedunculate oak (Quercus robur), as well as hybrid fir (Abies borisii regis) and umbrella pine (Pinus pinea), that are expected to face particular challenges in the future due to climatic change and anticipated changes in their future climatic envelop. These species have been evaluated in a time interval of 15-17 years (baseline and contemporary genetic data). The genetic diversity parameters employed for genetic monitoring were effective number of alleles (A_e), allelic richness (AR), Shannon’s information index (I), observed heterozygosity (H_o), gene diversity (H_s), latent genetic potential (LGP), and effective population size (N_e), In the majority of comparisons, extant genetic diversity was found reduced, however the differences were not statistically significant. In the genetically depauperate Pinus pinea the already very low genetic diversity did not recover. Moreover, fructification and natural regeneration were strong and abundant respectively in the former four species, while being weak and scattered in the latter. Results overall depict dynamic and idiosyncratic species outcomes and call for the maintenance and intensification of genetic monitoring assessments in the future.