Forest management has not impact on short local dispersal potential of two Nothofagus species

GALLO, LA; SOLA G; VENDRAMIN GG; EL MUJTAR, V.; MARCHELLI P

Bariloche

Conferencia; International Conference ?Adapting forests ecosystems and wood products to biotic and abiotic stress?; 2019

INTA - INRA

Understanding the impact of management on the dispersal potential of forest tree species is key in the context of global change due to gene flow implications on species evolution. We aim to determine logging impact on temperate Patagonian forests considering the ecological relevance and high quality wood of Nothofagus species. Comparison of historical (based on fine-scale spatial genetic structure (FSGS)) and contemporary (based on spatially explicit mating models) gene dispersal estimates were used. A total of 778 individuals (mature trees and saplings) of N. alpina and N. obliqua, from a managed plot (2.85 ha), were mapped and genotyped at nuclear microsatellites. Our work reveal significant FSGS and congruent historical and contemporary estimates of gene dispersal indicating that logging has not a significant impact on it. Contemporary estimates reveal local restricted seed (≤ 28 m) and pollen dispersal (≤ 48 m), no selfing and important seed and pollen immigration (up to 57%) from close surrounding area. Diameter at breast height and height of trees were associated with female and/or male fertility. Therefore, vigorous trees should be preserved homogeneously distributed to increase fecundity and dispersion maintaining forest genetic diversity. Results also support previous definition of Nothofagus genetic zones despite their narrow distribution range in Argentina. We will further discuss other implications for management, restoration and conservation of these forests.