Combined effects of tree canopy composition, landscape location, and growing season on Nothofagus forest seeding patterns in Southern Patagonia.

M TORO; A HUERTAS HERRERA; R SOLER ESTEBAN; MV LENCINAS; G MARTÍNEZ PASTUR

FOREST ECOLOGY AND MANAGEMENT

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2023 vol. 529

0378-1127

The ecological mechanisms that regulate seeding processes in temperate forests are poorly understood especiallyin the Southern Hemisphere. We studied the effect of different growing season metrics determined by theNormalized Difference Vegetation Index (NDVI) across eight annual periods between 2012 and 2020. Weanalyzed the seed production and biomass of two Nothofagus species in Tierra del Fuego (Argentina) to developnew tools for ecological forest management strategies. We focused on three forest types in coast and mountainlandscapes: (i) pure deciduous N. pumilio, (ii) pure evergreen N. betuloides, and (iii) mixed forests with a similarproportion of both species. We performed generalized linear models for each species to analyze the influence ofthe growing season metrics and regional climate patterns (temperature and rainfall) considering forest types oncoasts and mountains as main factors and analyzing seed production and biomass. Seed production and biomassannually varied with tree species growing at different landscape locations, with marked synchrony for each foresttype, but not between different species or landscape locations (e.g. deciduous and evergreen species presenteddifferent synchrony among years). Seed production and biomass were higher when NDVI-peak was high inN. pumilio and when the growing season end was late in N. betuloides. For N. pumilio, the seed production andbiomass were significantly leaded by growing season minimum temperature and growing season rainfall incoastal and mountain forests. For N. betuloides, the higher seed production and biomass were significantlyinfluenced by non-growing season maximum temperature, growing season rainfall and non-growing seasonrainfall in coastal and mountain forests. These outputs highlight the importance of considering the fluctuation ofthe growing season in the modeling of seed production and biomass. Forest management guidelines shouldforecast rainy years that may benefit seedling recruitment after stand management or conservation efforts oftarget species (e.g. simulations of population dynamics at stand-level, decisions about passive vs active restorationin degraded forests for recover of the natural ecosystem functions).