Search

Prevailing social, economic and political ideas and paradigms constitute the lens through which scientists observe, assess, and understand the world. This affects how we interpret and understand the mechanisms governing the interaction between organisms and has led, in most cases, to dominant explanations and paradigms that are difficult to overthrow. This is the case of ecological theory, whose perspectives have followed the rationale of societal changes. From the industrial revolution to very recently, species competition for resources was regarded as one of the main drivers of species interactions. Nowadays, a new and rapidly growing way of thinking emerged, fueled by the high sequencing capacities, ultra-resolution microscopy and the slowly growing number of different social and gender perspectives participating in ecological studies: that living beings are not just single organisms interacting with other single organisms, but complex communities of macro- and microorganisms living and evolving together. The information emerging from this field is bringing new light to previously disregarded aspects of the ecological interactions that, in our opinion, will change the main paradigms in ecology. As members of a South American scientific network of Aquatic Microbial Ecology (MicroSudAqua), here we propose to explore alternative explanations for ecological observations, searching for new traits accounting for cooperation between microorganisms as a fundamental evolutionary and ecological strategy., Las ideas y paradigmas sociales, económicos y políticos prevalecientes constituyen la lente a través de la cual las científicas y los científicos observamos, evaluamos y comprendemos el mundo. A menudo, esto impregna y afecta la interpretación de los mecanismos que rigen las interacciones entre organismos, y llega a generar paradigmas difíciles de poner en discusión. Un ejemplo es el caso de la teoría ecológica, cuyas perspectivas han seguido la lógica de los cambios sociales. Desde la época de la Revolución Industrial hasta muy recientemente, la competencia interespecífica por los recursos se consideró como una de las formas principales en que las especies interactúan. En la actualidad, presenciamos un cambio en la forma de pensar; su crecimiento es veloz, impulsado por las capacidades de secuenciación masiva, la microscopía de ultra resolución y la cantidad cada vez mayor de diferentes perspectivas sociales y de género con la que se abordan los estudios de ecología. Esta nueva perspectiva implica que los seres vivos no son organismos solitarios que interactúan con otros organismos solitarios, sino comunidades complejas de macro y microorganismos que conviven y evolucionan juntos. La información que emerge de este campo está dando nuevos aportes a aspectos antes ignorados de las interacciones ecológicas; en nuestra opinión, estos aportes cambiarán los principales paradigmas de la ecología. Como integrantes de la Red Científica Sudamericana de Ecología Microbiana Acuática (MicroSudAqua), en este trabajo exploramos explicaciones alternativas de las observaciones ecológicas, buscando nuevos rasgos que den cuenta de la cooperación entre microorganismos como una estrategia evolutiva y ecológica fundamental.

We used multiple approaches to analyze photosynthetic picoplankton (PPP) structure and production in a wetland in the Lower Paraná Basin (Argentina). A seasonal field survey was combined with an experimental study to analyze PPP variability under different light conditions. Flow cytometry analyses showed differences in PPP structure among the aquatic environments. Three main picoplankton populations were distinguished: phycocyanin-rich picocyanobacteria (Pcy), picoeukaryote (Peuk) and anaerobic anoxygenic photosynthetic bacteria (AnAnPB). The experimental study revealed important changes in PPP structure in relation to the light conditions imposed by floating plants: enclosures exposed to light showed a higher proportion of Peuk and Pcy over AnAnPB; in mesocosms covered by plants, just as in the highly vegetated relict lakes (ROLs), AnAnPB were dominant. Total picophytoplankton abundances varied from 1.7 x 104 to 4.6 x 105 cells mL–1 in the shallow lakes, and were lower (0.69 x 104 to 2.5 x 105 cells mL–1) in the ROLs. Annual variations in temperature and hydrological conditions influenced the PPP abundances, observing maximum values during the warm dry phase. The photosynthetic rates per unit area of PPP (PAPPP) and algae >3 µm (PA>3 µm) were measured in the aquatic environments in winter and summer: PA PPP (1.5 to 100 mg C m–2h–1) was lower than PA >3 µm and was directly affected by light, which was limiting under the dense floating plant cover