Diversidad fitoplanctónica en los cuencos principal y norte de la laguna Don Tomás (La Pampa. Argentina)

El presente trabajo analiza la composición, diversidad y riqueza específica de las especies fitoplanctónicas de la Laguna Don Tomás, un lago somero natural que pertenece a la región fisiográfica oriental de la provincia de La Pampa, durante un ciclo anual (2002-2003). La laguna posee una superfície aproximada de 200 ha, con una profundidad de 2,5-3 m y en esta oportunidad se consideran dos áreas de muestreo, los cuencos Principal y Norte. No se hallaron diferencias en los valores de temperaturas de ambos cuerpos de agua (p > 0.5) y el rango de variación entre invierno y verano fue entre 11 ◦ y 26 ◦C. Con respecto al pH se hallaron diferencias significativas (p 0.5) and the variation range between winter and summer was between 11 ◦ and 26 ◦C. Significant differences were found between basins regarding pH ( p < 0.01) Phytoplankton was characterized by an extensive variety of taxa qualitatively dominated by green algae. The specific richness of the Main Basin was larger than for the North Basin. The Main Basin showed a sharp decline in the specific richness in November associated with a blooming of Cyanophyceae. This blooming occurred again between March and April 2003 with a dominance of Planktothrix agardhil (Gom.) Anag. Kom., species that produced a high fish mortality

Biodiversidad fitoplanctónica en tres lagunas someras de la provincia de La Pampa, Argentina

The shallow lake system, Luan Lauquen of semi-permanent regime, it’s located in the eastern physiographic region, biogeographical Chaco domain, in La Pampa province. The aim of this contribution is to amplify the knowledge of the composition and distribution of algal species in the Pichi Luan, Ea. Ansin and Lonco-Che shallow lakes. The samples were collected in spring season 2010 and autumn 2011. The biological samples collected were set in formaldehyde at 4%. A total of 99 taxa were identified for the three shallow lakes of which 52% were Chlorophyta, 11 % Charophyta, 18% Cyanobacteria, 8% Ochrophyta and 11% remaining Euglenozoa. In autumn the algae species richness in the three shallow lakes, was higher in relation to the spring, where Chlorophyta of the Chlorococcales Order was found widely represented, corresponding the maximum number of species to the Pichi Luan shallow lake. In autumn for Lonco-Che, the Cyanobacteria species richness is stands out, while for the same date the Euglenozoa prevails in the Pichi Luan. The diatom species are equally distributed in spring at all sampling sites. Oscillatoria subbrevis, Pediastrum boryanum var. boryanum, Scenedesmus bijuga and Cyclotella meneghiniana taxa, were common in the three shallow lakes. The highest similarity S= 37%, according to Bray Curtis, was in spring between Pichi Luan and Lonco-Che shallow lakes.Facultad de Ciencias Naturales y Muse

Biodiversidad fitoplanctónica en tres lagunas someras de la provincia de La Pampa, Argentina

The shallow lake system, Luan Lauquen of semi-permanent regime, it’s located in the eastern physiographic region, biogeographical Chaco domain, in La Pampa province. The aim of this contribution is to amplify the knowledge of the composition and distribution of algal species in the Pichi Luan, Ea. Ansin and Lonco-Che shallow lakes. The samples were collected in spring season 2010 and autumn 2011. The biological samples collected were set in formaldehyde at 4%. A total of 99 taxa were identified for the three shallow lakes of which 52% were Chlorophyta, 11 % Charophyta, 18% Cyanobacteria, 8% Ochrophyta and 11% remaining Euglenozoa. In autumn the algae species richness in the three shallow lakes, was higher in relation to the spring, where Chlorophyta of the Chlorococcales Order was found widely represented, corresponding the maximum number of species to the Pichi Luan shallow lake. In autumn for Lonco-Che, the Cyanobacteria species richness is stands out, while for the same date the Euglenozoa prevails in the Pichi Luan. The diatom species are equally distributed in spring at all sampling sites. Oscillatoria subbrevis, Pediastrum boryanum var. boryanum, Scenedesmus bijuga and Cyclotella meneghiniana taxa, were common in the three shallow lakes. The highest similarity S= 37%, according to Bray Curtis, was in spring between Pichi Luan and Lonco-Che shallow lakes.Facultad de Ciencias Naturales y Muse

Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares.The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares.The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Biodiversidad fitoplactónica en tres lagunas someras de la provincia de La Pampa

El sistema de lagunas, Luan Lauquen, de régimen semipermanente, está ubicado en la región fisiográfica oriental, dominio biogeográfico del Chaco, en la provincia de La Pampa. El objetivo de esta contribución es ampliar el conocimiento de la composición y distribución de las especies de algas en Pichi Luan, Ea. Ansin y Lonco-Che. Las muestras se colectaron en la temporada de primavera 2010 y otoño de 2011. Las muestras biológicas colectadas se fijaron en formaldehído al 4%. Se identificaron un total de 99 taxas para las tres lagunas, de los cuales 52% fueron Chlorophyta, 11% Charophyta, 18% Cyanobacteria, 8% Ochrophyta y 11% restante Euglenozoa. En otoño, la riqueza de especies de algas en las tres lagunas fue mayor en relación con la primavera, donde se encontró que las Chlorophyta del orden Chlorococcales estaba ampliamente&nbsp; representada, correspondiendo el número máximo de especies a la laguna Pichi Luan. En otoño, para Lonco-Che, se destaca la riqueza de especies de Cyanobacteria, mientras que en la misma fecha prevalece el Euglenozoa en el Pichi Luan. Las especies de diatomeas se distribuyen por igual en primavera en todos los sitios de muestreo. Oscillatoria subbrevis, Pediastrum boryanum var. boryanum, Scenedesmus bijuga y Cyclotella meneghiniana, fueron comunes en las tres lagunas. La mayor similitud S = 37%, según Bray Curtis, fue en primavera entre Pichi Luan y Lonco-Che.The shallow lake system, Luan Lauquen of semi-permanent regime, it’s located in the eastern physiographic region, biogeographical Chaco domain, in La Pampa province. The aim of this contribution is to amplify the knowledge of the composition and distribution of algal species in the Pichi Luan, Ea. Ansin and Lonco-Che shallow lakes. The samples were collected in spring season 2010 and autumn 2011. The biological samples collected were set in formaldehyde at 4%. A total of 99 taxa were identified for the three shallow lakes of which 52% were Chlorophyta, 11 % Charophyta, 18% Cyanobacteria, 8% Ochrophyta and 11% remaining Euglenozoa. In autumn the algae species richness in the three shallow lakes, was higher in relation to the spring, where Chlorophyta of the Chlorococcales Order was found widely represented, corresponding the maximum number of species to the Pichi Luan shallow lake. In autumn for Lonco-Che, the Cyanobacteria species richness is stands out, while for the same date the Euglenozoa prevails in the Pichi Luan. The diatom species are equally distributed in spring at all sampling sites. Oscillatoria subbrevis, Pediastrum boryanum var. boryanum, Scenedesmus bijuga and Cyclotella meneghiniana taxa, were common in the three shallow lakes. The highest similarity S= 37%, according to Bray Curtis, was in spring between Pichi Luan and Lonco-Che shallow lakes

Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares.The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Producción primaria fitoplanctónica de un lago somero turbio orgánico en relación con el zooplancton (La Pampa, Argentina)

Primary production (PPr) is the energy fixed by autotrophic organisms. In aquatic ecosystems, it is mostly produced by photosynthetic processes performed by planktonic or benthic algae and macrophytes. In La Pampa, the ecology of shallow lakes has recently begun to be studied, but there is no reference inade to the algal PPr and how it is influenced by zooplankton. Since shallow lakes in La Pampa are different from those widely studied in Buenos Aires province, the objective of this contribution was to determine the phytoplanktonic PPr of an organic turbid shallow lake of the northeast La Pampa, and the influence of zooplankton in its valué. PPr was estimated 6 times along the day with the dissolved oxygen technique, using clear and dark bottles. To test the ef- fect of zooplankton on PPr estimates, we compared PPr with and without zooplankton, which was removed with a 40-micron mesh net. A higher concentration of nutrients was recorded than the typical pampasic shallow lakes of Buenos Aires province, Phytoplank- ton was dominated by Chlorophyta and the zooplankton assemblage was typical of low salinity environments. Zooplankton densities were reduced during noon-afternoon hours, what might indícate an important zooplankton migration process. Net PPr was similar to the detected in lakes at similar latitudinal location, but the máximum PPr per unít chlorophyll was higher than the recorded in organic turbid lakes of Buenos Aires Province. Zooplankton had a weak influence on PPr. Determinations from the two treat- ments did not show significant differences, except at 8 PM when the net PPr without zooplankton was three times higher than the treaíment with zooplankton.Instituto de Limnología "Raúl A. Ringuelet

Producción primaria fitoplanctónica de un lago somero turbio orgánico en relación con el zooplancton (La Pampa, Argentina)

Primary production (PPr) is the energy fixed by autotrophic organisms. In aquatic ecosystems, it is mostly produced by photosynthetic processes performed by planktonic or benthic algae and macrophytes. In La Pampa, the ecology of shallow lakes has recently begun to be studied, but there is no reference inade to the algal PPr and how it is influenced by zooplankton. Since shallow lakes in La Pampa are different from those widely studied in Buenos Aires province, the objective of this contribution was to determine the phytoplanktonic PPr of an organic turbid shallow lake of the northeast La Pampa, and the influence of zooplankton in its valué. PPr was estimated 6 times along the day with the dissolved oxygen technique, using clear and dark bottles. To test the ef- fect of zooplankton on PPr estimates, we compared PPr with and without zooplankton, which was removed with a 40-micron mesh net. A higher concentration of nutrients was recorded than the typical pampasic shallow lakes of Buenos Aires province, Phytoplank- ton was dominated by Chlorophyta and the zooplankton assemblage was typical of low salinity environments. Zooplankton densities were reduced during noon-afternoon hours, what might indícate an important zooplankton migration process. Net PPr was similar to the detected in lakes at similar latitudinal location, but the máximum PPr per unít chlorophyll was higher than the recorded in organic turbid lakes of Buenos Aires Province. Zooplankton had a weak influence on PPr. Determinations from the two treat- ments did not show significant differences, except at 8 PM when the net PPr without zooplankton was three times higher than the treaíment with zooplankton.Instituto de Limnología "Raúl A. Ringuelet

Ficoflora de la laguna Don Tomás (La Pampa, Argentina)

The work deals with the analyze composition and seasonal distribution of phytoplantonic species of Don Tomas Shallow lake during an annual cycle. Six monthly samples were collected (August 2002 to July 2003) and they were qualitatively studied. The physical and chemical parameters were registered in the same time. The index of similarity of Sorensen was made In order to determine the degree of similarity of the seasonal distribution of the taxa. The phytoplanctonic taxocenosis community richness specific of the was of 159 taxa. Groups with a noticeable seasonal distribution were showed with cluster analyzed. Four seasonal groups were identified. September, October and November correspond to the spring; the second group, summer, was integrated for December, January and February, and the third group was constituted for March, April, May, June and July. Different environmental conditions during the winter of 2002 had isolated the results of August.El objetivo del presente trabajo es analizar la composición y la distribución estacional de las especies fitoplanctónicas de la Laguna Don Tomás durante un ciclo anual. Se colectaron muestras mensuales (agosto 2002 a julio 2003), los que se estudiaron cualitativamente. Asimismo, se analizaron parámetros fisicoquímicos. Se realizó un análisis de clusters en base al índice de similitud de Sorensen, para determinar la distribución de los taxa. La riqueza específica de la taxocenosis fitoplanctónica fue de 159 taxa. Los cluster mostraron agrupamientos con una marcada distribución estacional. Se identificaron cuatro grupos. El primero compuesto por los meses de septiembre, octubre y noviembre corresponden a la primavera, el segundo grupo, verano, integrado por diciembre, enero y febrero y el tercer grupo está constituido por marzo, abril, mayo, junio y julio. Los resultados correspondientes al mes de Agosto se aíslan del resto del año por condiciones ambientales particulares