Disentangling microstructure and environmental conditions in high-altitude Andean microbialite systems (Catamarca, Argentine Puna).

The study of microbialites development is a key tool to understand environmental pathways during deposition. We provide a detailed analysis of modern Central Andean microbialites from high-altitude lakes. The stratigraphic record of Turquesa Lake shows a significant short-term recolonization by microbialite-producing microorganisms during environmental stress. Far from a crisis paradigm, the coasts and paleocoasts of Turquesa lake exhibit three microbialitic buildups formed along different stages, providing a good study case of biological resilience of these systems in harsh environments. The MI and MII microbialite buildups occupied two paleocoasts. Both are composed of oncoids with micritic to microsparitic textures. Morphological, textural and mineralogical similarities between the two buildups suggest that they were formed at different times, but under very similar environmental conditions. The microorganisms that produced the microbialitic buildup MIII are currently colonizing the coast of this lake. The previous oncoid morphology change to a parallel micritic-spartic lamination. This remarkable changes in the microstructure can be explained by an important environmental change caused by the isolation of the Peinado Lake, and a subsequently microorganism adaptation. This microbialite structures can be proposed as an interesting modern analogue for environmental changes along the geological record.

Short-term microbialite resurgence as indicator of ecological resilience against crises (Catamarca, Argentine Puna).

Microbialite-producing microorganisms that inhabit the Puna lakes are traditionally considered constituents of fragile microsystems, unable to resist important environmental variations. Nevertheless, this region has experienced significant climatic fluctuations during the Holocene, raising the unsolved issue on how microbialite-forming systems have been able to resist these changes. Turquesa lake, located within Quaternary Peinado lake-basin (Puna), faces a hydric crisis in the last decades, which modified their physicochemical conditions. However, there has been a rapid re-establishment of the microbialite systems once the main parameters were stabilized, which allowed the establishment of three new microbialite levels in the coast and paleo-coastline. The aim of this contribution is to report for the first time microbialite levels in Turquesa lake, providing a multiscale analysis, besides an accurate study of the physico-chemical context of the lake. This new record provided us the opportunity to demonstrate the short-term resilience capacity of these microbialite-producing microorganisms to climatic changes, offering a key approach to understand analogue processes throughout Earth history.

Effects of pre- and post-veraison cluster thinning on Montepulciano and Cabernet Franc grape varieties in southern Brazil highlands / Raleio de cachos próximo ao véraison nas variedades Montepulciano e Cabernet Franc em região de elevada altitude do sul do Brasil

The objective of this study was to evaluate the effects of pre- and post-veraison cluster thinning on the physicochemical characteristics of Montepulciano and Cabernet Franc grape varieties grown in regions 900 m above sea level (ASL) in Santa Catarina, southern region of Brazil. The experiment was conducted in two commercial vineyards, Montepulciano vineyard located at 28º12"58""S, 50º06"45""W, 1,185 m ASL during the 2007, 2008 and 2009 vintages; and Cabernet Franc vineyard located at 2815"20"S, 4956"60"W, 1,284 m ASL, during the 2010 and 2011 vintages. Treatments consisted on cluster thinning at three distinct moments for both varieties: during veraison, about 15 days pre-veraison and 15 days post-veraison. For Montepulciano, when cluster thinning is performed post-veraison, there is a reduction in cluster mass and a slight reduction on the acidity of grapes. For Cabernet Franc, when cluster thinning is performed during veraison, there is an increase in total soluble solids of grapes. In general, cluster thinning is recommended two weeks pre- or post-veraison for Montepulciano and Cabernet Franc wine grapes produced in southern Brazilian highlands.

O presente trabalho teve como objetivo avaliar o efeito do raleio de cachos próximo ao véraison sobre as características físico-químicas das variedades Montepulciano e Cabernet Franc cultivadas em regiões acima de 900m de altitude no estado de Santa Catarina, Sul do Brasil. Os ensaios foram conduzidos em vinhedos comerciais da variedade Montepulciano coordenadas 28º12"58""S, 50º06"45""W, 1,185 m de altitude durante as safras 2007, 2008 e 2009; e da variedade Cabernet Franc coordenadas 2815"20"S, 4956"60"W, 1,284 m de altitude durante as safras 2010 e 2011. Os tratamentos consistiram no raleio de cachos realizado em três momentos para ambas as variedades: Na véraison", cerca de 15 dias antes da véraison e 15 dias após "véraison". Para Montepulciano, quando o raleio de cachos é realizado após a "véraison" há uma redução da massa do cacho, bem como uma redução na acidez das uvas. Para Cabernet Franc quando o raleio de cachos é realizado durante a "véraison" há um aumento no teor de sólidos solúveis. Em geral, o raleio de cachos pode ser indicado durante as duas semanas que antecedem ou sucedem a virada de cor das bagas para as variedades Montepulciano e Cabernet Franc produzidos nas regiões de altitude do sul do Brasil.

Effects of pre- and post-veraison cluster thinning on Montepulciano and Cabernet Franc grape varieties in southern Brazil highlands / Raleio de cachos próximo ao véraison nas variedades Montepulciano e Cabernet Franc em região de elevada altitude do sul do Brasil

The objective of this study was to evaluate the effects of pre- and post-veraison cluster thinning on the physicochemical characteristics of Montepulciano and Cabernet Franc grape varieties grown in regions 900 m above sea level (ASL) in Santa Catarina, southern region of Brazil. The experiment was conducted in two commercial vineyards, Montepulciano vineyard located at 28º12"58""S, 50º06"45""W, 1,185 m ASL during the 2007, 2008 and 2009 vintages; and Cabernet Franc vineyard located at 2815"20"S, 4956"60"W, 1,284 m ASL, during the 2010 and 2011 vintages. Treatments consisted on cluster thinning at three distinct moments for both varieties: during veraison, about 15 days pre-veraison and 15 days post-veraison. For Montepulciano, when cluster thinning is performed post-veraison, there is a reduction in cluster mass and a slight reduction on the acidity of grapes. For Cabernet Franc, when cluster thinning is performed during veraison, there is an increase in total soluble solids of grapes. In general, cluster thinning is recommended two weeks pre- or post-veraison for Montepulciano and Cabernet Franc wine grapes produced in southern Brazilian highlands.(AU)

O presente trabalho teve como objetivo avaliar o efeito do raleio de cachos próximo ao véraison sobre as características físico-químicas das variedades Montepulciano e Cabernet Franc cultivadas em regiões acima de 900m de altitude no estado de Santa Catarina, Sul do Brasil. Os ensaios foram conduzidos em vinhedos comerciais da variedade Montepulciano coordenadas 28º12"58""S, 50º06"45""W, 1,185 m de altitude durante as safras 2007, 2008 e 2009; e da variedade Cabernet Franc coordenadas 2815"20"S, 4956"60"W, 1,284 m de altitude durante as safras 2010 e 2011. Os tratamentos consistiram no raleio de cachos realizado em três momentos para ambas as variedades: Na véraison", cerca de 15 dias antes da véraison e 15 dias após "véraison". Para Montepulciano, quando o raleio de cachos é realizado após a "véraison" há uma redução da massa do cacho, bem como uma redução na acidez das uvas. Para Cabernet Franc quando o raleio de cachos é realizado durante a "véraison" há um aumento no teor de sólidos solúveis. Em geral, o raleio de cachos pode ser indicado durante as duas semanas que antecedem ou sucedem a virada de cor das bagas para as variedades Montepulciano e Cabernet Franc produzidos nas regiões de altitude do sul do Brasil.(AU)