Deciphering tree responses to a changing climate: A case study in Southern beeches of Patagonia.

CAGNACCI, J.; CAVIA, R.; ESTRAVIS-BARCALA, M.; MARTINEZ MEIER, A.; GONZALEZ POLO, M.; WANG, H.; MATTERA, G.; GAISCHUK, S.; WEIGEL, D.; BELLORA, N.; LIA, V.V.; ARANA, M.V.

Congreso; XXXIII Reunión Argentina de Fisiología Vegetal; 2021

. Thus, understanding how trees respond to changes in the environment becomes essential in the context of climate change. This work takes place in the Patagonian forests, the southernmost woody ecosystems of the world, where two Nothofagus species co-exist in non-overlapping thermal niches. While N. obliqua is predominant at 650-850 meters above the sea level (m), N. pumilio inhabits the higher montane environments, above 1000 m. Combining artificial germination pulses with reciprocal transplantations in the field, the regeneration -seedling survival- of these species was studied during the first year of growth, under several climatic scenarios generated across altitude and time. Furthermore, in the interest of studying species’ performance, phenotypes of two-year-old individuals planted both inside and outside their natural range were registered. The results show that early stages in life cycle –seedling emergence and survival- are disadvantaged for N. obliqua in higher and colder areas outside its range. In contrast, N. pumilio’s seedlings survived successfully outside its range in warmer environments. Interestingly, in the same areas older plants of this species presented physiological stress, whereas individuals of N. obliqua had an equal performance when studied inside and outside its natural range. This results indicate that these species present constraints in development at different stages of their life, which ultimately modulates their pattern of abundance across altitude.