Inland aquatic ecosystems reproduce on a small scale the terrestrial ones in each of their droplets.
A microscope, curiosity and just a drop of water are enough to enter a captivating and beautiful world from which so many life lessons can be learned.
Among the producing organisms that form part of all these enclaves such as rivers, ponds, lagoons or peat bogs, cyanobacteria, diatoms and chlorophyceae are among the most common and abundant, and within the latter group, désmids are particularly well represented, especially in acidic environments such as peat bogs. Many of them are excellent bioindicators, and their presence alone allows us to know the conditions of the environment in which they live.
The opportunity given to us by Chile to direct the first international course on peatland microscopy promoted by the Universidad de La Frontera, thanks to the efforts of Professor Rubén Carrillo, Head of the Department of Environmental Sciences and the Dean's Office of this Faculty, has allowed us to have a first contact and study some unique aquatic ecosystems such as the most austal peatlands in this country and in America, and the mountain lagoons in the volcanic area of the Conguillío National Park.
Peatlands with Sphagnum magellanicum and Donatia fascicularis are less acidic than others in Chile at more southerly latitudes and richer in microbial biodiversity. The image shows in detail the floristic composition of a Donatia peatland with Sphagnum located in the National Protected Site "Las Araucarias" in the Araucanía region (Chile).
In these ecosystems, the environmental conditions are very different in terms of location, altitude, climate and substrate characteristics, butdespite this, their microbial biocenoses have common characteristics. Producing organisms belong to the same groups, as do primary consumers and predators, although their abundance and representation are obviously different.
As a brief outline, we show here some of the most common producer micro-organisms in the lakes of the Conguillío Natural Park and the circumpolar peat bogs around Quillaipe.
Sampling of a Donatia peatland with Sphagnum located in the National Protected Site "Las Araucarias" by participants in the first international course on peatland microscopy, held in Chile.
The peatlands of Chile are characterised by their extreme acidity and it is difficult to find the great diversity of désmids or diatoms that are present in these wetlands in other regions. Only organisms adapted to these extreme conditions are able to survive, as is the case with some species of Pinnularia or Cylindrocystis, such as those shown here.
In contrast, in less acidic environments, such as the lakes around Conguillío, the diversity of diatoms is very notable and their forms are often free and sometimes form colonial aggregates that facilitate their flotation and survival, as is the case with Fragilaria.
The use of different microscopic illumination techniques: brightfield, darkfield, phase contrast, polarisation and epifluorescence, with the equipment provided by Motic Europa, makes it possible to obtain complementary views of the same organism and even to know its vital activity.
Working laboratory at the Faculty of Environmental Sciences at the Universidad de la Frontera (UFRO) in Temuco with microscopic equipment for the observations and photographs of the sampled material referred to in this article.
This is especially useful when the aim is to assess the trophic state of a given aquatic environment and in this particular case, epifluorescence techniques allow us to know the photosynthetic activity and morphology of chloroplasts and to assess damage or possible dysfunctions with just one observation.
Motic Panthera C2 trinocular equipped with the FLED epi-fluorescence module and provided with a condenser and objectives for phase contrast and darkfield observation.
The microscope equipment that Motic Europe has generously loaned us temporarily, a trinocular Motic Panthera CC equipped with the FLED module for epifluorescence and equipped with a condenser and objectives for phase contrast and darkfield observation, is proving to be an invaluable tool for us, is proving to be an invaluable working tool, with which we have taken the microscopic images that accompany this article, made possible thanks to the collaboration agreement of the Universidad de la Frontera with the Duero-Douro International Biological Station (EBI) and Motic Europe.
Some of the most common producer micro-organisms in Chilean Sphagnum peat bogs:
Pinnularia cardinalis is one of the few diatoms that can survive under high acidic conditions in Chilean peat bogs, with pH values slightly above 4. Observation at 400x magnification with phase contrast in trinocular Motic Panthera C2, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 objective.
Neidium productum is a free-living diatom with characteristic sinuous contours. It is not a very common species, but it is present in the lakes of the Conguillío National Park and its surroundings, where it does not tolerate excessive acidity of the medium. Observation at 400x magnification with phase contrast in trinocular Motic Panthera C2, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 objective.
Cymbella cistula is a free-living diatom relatively common in many freshwater ecosystems. Conguillío National Park. Observation at 400x magnification with phase contrast in trinocular Motic Panthera C2, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 objective.
Epithemia sorex. This is a small, free-living diatom that in pleural view shows a marked ornamentation of striae. It is present in the lakes of the Conguillío National Park, without being abundant. Observation at 400x magnification with phase contrast in trinocular Motic Panthera C2, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 objective.
Fragilaria crotonensis. Colonial diatom that tends to form long, ribbon-like structures in many aquatic environments, and is fairly tolerant of the physical and chemical conditions of the environment in which it lives. It is found in the lakes of the Conguillío National Park without becoming abundant. Observation at 400x magnification with phase contrast in trinocular Motic Panthera C2, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 objective.
Cylindrocystis brebiisonii. This is a small green alga related to the désmids and able to withstand extremely dry environments. It comes from the Quillaipe peat bogs and has been photographed to observe the structure and activity of the chloroplasts using UV epi-illumination with the Motic FLED module at 400x magnification in the Motic Panthera C2 trinocular unit, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 Motic objective 40X/0.65/Ph2.
Cylindrocystis brebiisonii. This is a small green alga related to the désmids and able to withstand extremely dry environments. It comes from the Quillaipe peat bogs and has been photographed to observe the structure and activity of the chloroplasts using a Motic Panthera C2 trinocular equipment, with epifluorescence FLED module. Motic Plan UC 40X/0.65/Ph2 Motic objective 40X/0.65/Ph2
Copyright: Antonio Guillén
Proyecto Agua - By Antonio Guillén