Dendroecology of Nothofagus on flooded lakeshores caused by Perito Moreno Glacier, Patagonia, Argentina.

AMOROSO, M.; GUERRIDO, C.; RICARDO VILLALBA; MILAGROS RODRIGUEZ CATÓN

Mendoza

Conferencia; AMERIDENDRO 2016; 2016

IANIGLA - CONICET

Perito Moreno Glacier obstructed the Canal de Los Témpanoscausing flooding of Lago Argentino since 1936. These floodscould be considered large-scale events, according to standdynamic theory, removing vegetation and periodically alteringforest succession. While forest recruitment is well documentedfor avalanches, landslides, fires, etc. it is not the same in the caseof floods. The aim of this study was to document throughdendrochronology and spatial statistics, forest recolonization ofthe flooded shores of Lago Argentino. A total of 780 seedlingswere sampled in 10 plots. Species and individual position weremarked in each plot. Height and diameter in the base (DAB) weremeasured. Samples were taken from seedlings with > 5 cm DABusing increment borer. Smaller samples were removed and cuttransversely between root and stem. Samples were processedusing conventional techniques in dendrochronology. Dates werevisually established. Three years after the flood of 1988,Embothrium coccineum, and three Nothofagus were present.Maximum age of saplings recruited was 17 years (average 5-10years), considering 2004 as unified sampling date for all plots.Seedlings were detected with a clustered spatial pattern in 100%of the plots, using univariate L function. Applying the samefunction per species, 100%-clustered patterns were alsodetected. Using L cross bivariate function, significant interactionbetween species occurred in 100% of the plots, where at leasttwo species were present. In conclusion, the age of recruitmentcoincided with the last large-scale flooding of 1988. There are 6species of trees in the area, 4 of them colonized the shore.Clustering patterns could be determined by soil and siteconditions.