Valeria Casa- PhD Biology
- researcher at National University of General San Martín
Valeria Casa
- PhD Biology
- researcher at National University of General San Martín
Early-career scientist studying diatom ecology and taxonomy in wetlands to assess human impact through bioindicators.
About
34
Publications
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Introduction
I am a biologist interested in the ecology, limnology, and taxonomy of diatoms (and other protists). My research focuses mainly on the use of diatom communities as indicators of environmental changes (natural and anthropogenic) in wetlands, especially peat bogs in Tierra del Fuego, Antarctic ecosystems and urban nature reserves.
Current institution
Additional affiliations
January 2012 - present
Position
- PhD student in Biology (UBA)
Description
- Evaluación de la comunidad de diatomeas como indicadoras ambientales en turberas de Tierra del Fuego.
Publications
Publications (34)
Nuestro proyecto fue aprobado en la Convocatoria de Extensión Universitaria "UNIVERSIDAD, CULTURA y TERRITORIO 2022" buscando apoyar el desarrollo de la Reserva Natural Urbana de La Defensa, recientemente creada en El Palomar (Morón). Actualmente, se observa una drástica disminución de diversidad nativa y de espacios verdes limitando el acceso que...
El 14 de agosto de 2023 se desató un incendio de origen
desconocido en el sector núcleo de la reserva, un área
representativa del pastizal pampeano, quemando aproximadamente
1,22 ha. El incendio inicial duró cerca de cinco horas y, aunque fue
controlado, se reavivó intermitentemente durante los dos días
siguientes hasta su extinción total. El 17 de...
Wetlands are ecosystems characterised by standing water or waterlogged soils, with properties distinct from aquatic and terrestrial ecosystems. Despite their significant contributions to society, they have historically been viewed as wastelands, leading to rapid global loss and degradation. In response, the Ramsar Convention promotes policies for t...
Wetlands are valued for their biodiversity, water reservoir function, and contributions to human welfare, they provide 40% of Nature’s benefits to humanity but face threats from land use changes, pollution, and overexploitation. Peatlands, a distinct wetland type that covers 3% of the global land surface, host a remarkable
diversity of diatom speci...
Los estudios sobre el cambio climático prevén el incremento de eventos climáticos extremos y el aumento de la presión antrópica sobre los
ecosistemas dado el aumento poblacional y la disminución de áreas
naturales inmersas en la matriz urbana. En este contexto, las reservas
naturales urbanas cumplen un rol fundamental como refugio de flora y
fauna...
El Bajo Delta del Paraná es uno de los ambientes más vulnerables debido a la presión antrópica por el avance agrícola, urbano, la contaminación y la fragmentación del hábitat. Todo esto lleva a una gran pérdida en la biodiversidad. En el partido de Tigre está en evaluación la creación de una Reserva Natural Municipal. Su ubicación es estratégica pa...
Peat bogs have an important role in the carbon cycle, as they may be sinks or sources of carbon dioxide and methane, depending on the environmental conditions. These wetlands represent large reservoirs of freshwater capable of mitigating drought-flood events, with important implications for water quality and hydrological balance. The key nature con...
La cuenca del Río Turbio (RT) es un sistema expuesto a diversas actividades urbanas, rurales y minero-industriales. A fin de conocer la calidad del agua de la cuenca previamente a la puesta en marcha de la Central Termoeléctrica Río Turbio (CTRT), en diciembre de 2019 se muestrearon 12 sitios, 9 en el Rio Turbio (RT1-9), y otros 3 en sus tributario...
Las diatomeas son los protistas más diversos en la tierra. Anteriormente se creía que la mayoría de la especies de diatomeas poseían una distribución global. Sin embargo, cada vez más estudios comprueban que existe un alto grado de endemismo en las distintas regiones estudiadas. Las turberas son humedales de climas fríos que albergan una biodiversi...
As functional traits are conserved at different phylogenetic depths, the ability to detect community assembly processes can be conditional on the phylogenetic resolution; yet most previous work quantifying their influence has focused on a single level of phylogenetic resolution. Here, we have studied the ecological assembly of bacterial communities...
Todos los autores contribuyeron igualmente a este trabajo La pandemia de Covid-19 ha generado profundos cambios en las actividades cotidianas de la sociedad. En particular, las medidas de distanciamiento plantearon el desafío de pasar de la educación presencial a los entornos virtuales. Un importante objetivo de la materia Biología II es que el alu...
By the end of the exceptionally warm and stormy autumn of 2018, a fish kill occurred in a small hypertrophic pond located in a recreative green area in Buenos Aires (BA, Argentina). As there were no visible signs of an algal bloom, the causes for the die-off were investigated. On 1st June, the pond was sampled while fish, mostly Bryconamericus iher...
The metacommunity theory proposes that local habitats are connected by dispersal, and species within each local habitat respond to biotic and abiotic interactions, influencing community assembly. These ecological processes could operate at different space, time and phylogenetic scales.
Here, we studied bacterial assembly processes at one specific s...
By the end of the exceptionally warm and stormy autumn of 2018, a fish kill occurred in a small hypertrophic pond located in a recreative green area in Buenos Aires (BA, Argentina). As there were no visible signs of an algal bloom, the causes for the die-off were investigated. On 1st June, the pond was sampled while fish, mostly Bryconamericus iher...
Antarctic biodiversity is threatened by climate change, biological invasions, contamination and increasing human footprint. In particular, and despite their high relevance, Antarctic wetlands are poorly surveyed and understood. Cierva Point is a wetland landscape nominated as Antarctic Specially Protected Area No. 134 on account of its exceptional...
Questions
Responses of wetland systems to grazing can be highly variable with both positive or negative responses. However, the sustainable use of wetlands for grazing will depend on the management implemented and the resilience of each type of them. In this context, we addressed the question: will the vegetation in the studied wetland be able to r...
Background and aims – A few years ago, a new survey started of the freshwater diatom flora from peatbogs of Tierra del Fuego (southern Argentina). During this survey, an unknown fragilarioid diatom belonging to the genus Distrionella that could not be identified using the currently available literature was discovered. Methods – Using both Light Mic...
Nuestro objetivo fue estudiar la variación del ensamble de diatomeas en relación a los sustratos en donde se desarrollan dentro un cuerpo de agua.
Se extrajeron muestras de las diatomeas asociadas a los sedimentos y a 3 especies de musgos en 3 lagunas (A, B y C) de la turbera Rancho Hambre, Tierra del Fuego. A partir de ellas, se realizaron prepar...
The main goal of this study was to examine the nutritional condition of Engraulis anchoita larvae during the austral spring-summer seasons of 2010/2011 and 2012/2013 in highly productive waters in the southwestern Atlantic Ocean called El Rincón. RNA/DNA (RDs) index and derived index of Growth performance (Gpf) were used. Significant differences we...
The Riacho Formosa is one of many autochtonous watercourses running along the subtropical region of the Wet Chaco Plains and draining into Paraguay River. Their typical hydrological cycle is characterized by a late winter low phase and a high phase throughout the warm season. As part of a baseline characterization, the composition and structure of...
During a survey of the freshwater aquatic diatom flora of two peat bog areas in Tierra del Fuego, southern Argentina, six taxa belonging to the genus Frustulia that could not be identified were observed. Comparison with the type material of Frustulia (Navicula) crassinervia separated the Tierra del Fuego populations showing some resemblance as a ne...
A new centric diatom belonging to the genus Aulacoseira was found during a survey of the diatom community from peatbogs of Tierra del Fuego (southern Argentina). The present paper describes Aulacoseira frenguelliana sp. nov. based on detailed light and scanning electron microscopy and compares its morphological features with similar species. Aulaco...
Los humedales son ambientes ampliamente representados en toda Latinoamérica y cuna de gran diversidad biológica. Las turberas son un tipo de humedal principalmente de climas fríos y húmedos, caracterizadas por acumular materia orgánica en condiciones de anegamiento y acidez. La mayoría de turberas de Argentina se encuentran en la isla Tierra del Fu...
During a survey of the freshwater aquatic diatom flora of two peat bog areas in Tierra del Fuego, southern Argentina, a new taxon belonging to the genus Stauroneis that could not be identified was observed. Based on detailed light and scanning electron microscopy observations and comparison with similar larger-celled Stauroneis species worldwide, t...
Peat bogs are regarded as extreme environments due to their low pH and low nutrient concentration, and thus hold a unique biota adapted to these particular conditions. The island of Tierra del Fuego encompasses the southernmost extensive peat bog area in the world, and is therefore particularly interesting from a biogeographical viewpoint. Within t...
En las últimas décadas hubo un desplazamiento de la ganadería a zonas isleñas del Delta del Paraná. Allí se realizó un estudio preliminar para evaluar comparativamente el efecto del ganado sobre variables del suelo y la biota en 3 ambientes (Albardón, Media Loma y Carrizal). Dado que las comunidades de algas del suelo funcionan como indicadoras de...
Las turberas son humedales típicos de Tierra del Fuego. Muchas de ellas albergan pequeños cuerpos de agua en una matriz formada por el musgo Sphagnum magellanicum. Como parte de un estudio multidisciplinario sobre la biodiversidad de estos sistemas, se realizó una caracterización ambiental comparativa de dos turberas fueguinas pertenecientes a cuen...
La anchoíta Argentina Engraulis anchoita constituye un recurso poco explotado en la actualidad, pero de gran potencialidad pesquera. Debido a la situación pesquera mundial y local, podría ser explotada más intensamente en el futuro. Además cumple un papel central como soporte en la cadena trófica de diversas especies de interés comercial. La activi...
