Alexander Galán

Universidad Católica del Maule | UCM · Centro de Investigación de Estudios Avanzados del Maule - CIEAM. Vicerrectoría de Investigación y Postgrado

Concepción Bay is a socio-economic and ecologically important embayment, whose hydrographic variability has been historically regulated by wind-modulated seasonal upwelling events during spring-summer and by freshwater from precipitation and river discharges during fall-winter. This system is subject to several anthropogenic and environmental strai...

Coastal upwelling ecosystems support some of the most productive fisheries of the planet together with a large shellfish aquaculture sector that depends on oceanographic processes to deliver planktonic larvae to replenish and feed the farmed stock. Coastal shellfish aquaculture operations in Chile and Perú have experienced large interannual fluctua...

Using 19 years of remotely sensed Enhanced Vegetation Index (EVI), we examined the effects of climatic variability on terrestrial vegetation of six protected areas along southwestern South America, from the semiarid edge of the Atacama desert to southern Patagonia (30°S-51°S). The relationship between satellite phenology and climate indices, namely...

The coastal region off Chilean Patagonia has been poorly studied due to the lack of available observations. Here we analyzed, by the very first time, biogeochemical (BGC) data to elucidate the role that biological and physical processes play on nitrate, oxygen, pH and hydrographic variables, along a salinity gradient off central Patagonia. Argo flo...

Geochemical and stable isotope measurements in the anoxic marine zone (AMZ) off northern Chile during periods of contrasting oceanographic conditions indicate that microbial processes mediating sulfur and nitrogen cycling exert a significant control on the carbonate chemistry (pH, A T , DIC and p CO 2 ) of this region. Here we show that in 2015, a...

Plant-fungi interactions have been identified as fundamental drivers of the plant host performance, particularly in cold environments where organic matter degradation rates are slow, precisely for the capacity of the fungal symbiont to enhance the availability of labile nitrogen (N) in the plant rhizosphere. Nevertheless, these positive effects app...

The strong seasonal variability in physical-chemical conditions of the Eastern South Pacific Ocean creates an ideal setting to study spatiotemporal distribution of key marine microbial communities. We herein report a nearly 4-year-long time series of the variability in amoA gene counts of ammonia oxidizing archaea (AOA) and bacteria (betaproteobact...

Coastal upwelling regions represent less than 2% of the marine biosphere's volume. Nonetheless, local biogeochemical processes have a considerable impact on the structure and functioning of the global oceans. In this study we characterize the evolution of biogeochemical properties during the upwelling seasons of 2009 and 2010 in the coastal ecosyst...

The upwelling system off central Chile (36.5∘ S) is seasonally subjected to oxygen (O2)-deficient waters, with a strong vertical gradient in O2 (from oxic to anoxic conditions) that spans a few metres (30–50 m interval) over the shelf. This condition inhibits and/or stimulates processes involved in nitrogen (N) removal (e.g. anammox, denitrificatio...

The upwelling system off central Chile (36.5&degree: S) is seasonally subjected to oxygen (O2) deficient waters, with a strong vertical gradient in O2 varying from oxic to anoxic conditions on a scale of a few meters (30–50 m interval) over the shelf. This condition inhibits and/or stimulates processes involved in nitrogen (N) removal (e.g., anammo...

Spatial environmental heterogeneity influences diversity of organisms at different scales. Environmental filtering suggests that local environmental conditions provide habitat-specific scenarios for niche requirements, ultimately determining the composition of local communities. In this work, we analyze the spatial variation of microbial communitie...

Coastal upwelling areas are highly productive marine systems in which the development of oxygen-depleted conditions and the availability of diverse electron donors (e.g., organic matter, , H2S) favor the processes involved in nitrogen (N) loss. We characterize the temporal and vertical variability of anammox and denitrification over the continental...

Conventional denitrification and anaerobic ammonium oxidation (anammox) contributes to nitrogen loss in oxygen-deficient systems, thereby influencing many aspects of ecosystem function and global biogeochemistry. Mejillones Bay, northern Chile, presents ideal conditions to study nitrogen removal processes, because it is inserted in a coastal upwell...

Conventional denitrification and anaerobic ammonium oxidation (anammox) contributes to nitrogen loss in oxygen-deficient systems, thereby influencing many aspects of ecosystem function and global biogeochemistry. Mejillones Bay, northern Chile, presents ideal conditions to study nitrogen removal processes, because it is inserted in a coastal upwell...

Anammox is the anaerobic oxidation of ammonium by nitrite or nitrate to yield N2. This process, along with conventional denitrification, contributes to nitrogen loss in oxygen-deficient systems. Anammox is performed by a special group of bacteria belonging to the Planctomycetes phylum. However, information about the distribution, activity, and cont...

In recent years, our group has been studying the microbial communities of the water column associated with the oxygen minimum zone (OMZ) off northern Chile and Peru, trying to understand who the main players are in the OMZ biogeochemical cycles and which metabolic strategies they are using. For that, we are combining flow cytometry, molecular techn...