Logo Repositorio Institucional

Por favor, use este identificador para citar o enlazar este ítem: http://dspace.ucuenca.edu.ec/handle/123456789/29070
Título : Limnology and trophic status of glacial lakes in the tropical Andes (Cajas National Park, Ecuador)
Autor: Van Colen, Willem
Mosquera, Pablo
Vanderstukken, Maarten
Goiris, Koen
Carrasco, María Cecilia
Decaestecker, Ellen
Alonso, Miguel
Leon Tamariz, Fabian
Muylaert, Koenraad
Correspondencia: Van Colen, Willem, willem.vancolen@kuleuven-kulak.be
Palabras clave : High-Elevation Tropical Lakes
Nutrient Limitation
Primary Production
Páramo
Area de conocimiento FRASCATI amplio: 1. Ciencias Naturales y Exactas
Area de conocimiento FRASCATI detallado: 1.5.8 Ciencias del Medioambiente
Area de conocimiento FRASCATI específico: 1.5 Ciencias de la Tierra y el Ambiente
Area de conocimiento UNESCO amplio: 05 - Ciencias Físicas, Ciencias Naturales, Matemáticas y Estadísticas
Area de conocimiento UNESCO detallado: 0521 - Ciencias Ambientales
Area de conocimiento UNESCO específico: 052 - Medio Ambiente
Fecha de publicación : 2017
Volumen: volumen 62, número 3
Fuente: Freshwater biology
metadata.dc.identifier.doi: 10.1111/fwb.12890
Tipo: ARTÍCULO
Abstract: 
The tropical Andes has a high density of glacial lakes that are situated in the high-altitude páramo (3500–4500 m). Ecological information about such lakes is scant despite the fact that these lakes are an important source of water for drinking, irrigation and electricity generation and feed several major tributaries of the Amazon. In this study, we provide data on a survey of 31 lakes in Cajas National Park (Ecuador). Two of the lakes were monitored monthly during one year. In situ nutrient addition experiments were carried out in three of the lakes. Seasonal monitoring in two lakes revealed a thermal stratification of the water column between October and June, with a small temperature difference between epi- and hypolimnion (2–3 °C). Oxygen depletion of the hypolimnion towards the end of the stratification period indicated that no complete mixing of the water column occurred during stratification. There was no evidence of depletion of nutrients in the epilimnion or accumulation in the hypolimnion during stratification. There were also no clear seasonal changes in chlorophyll-a (Chl-a) concentration nor in phytoplankton community composition in the two lakes. Inputs of dissolved organic carbon (DOC) from the vegetated catchment resulted in high DOC concentrations (median 2.9 mg L−1) compared to temperate mountain lakes. Water transparency was relatively low, with a median extinction coefficient for photosynthetic active radiation of 0.50 m−1 and for UV-B radiation of 10.13 m−1. Although the thermocline was deep and water transparency was low, estimates of the critical depth for photosynthesis were deeper than the mean water depth in all lakes, suggesting that phytoplankton was not light limited. The phytoplankton community was dominated by chlorophytes (e.g. Oocystis), diatoms (small Cyclotella spp.) or small colonial cyanobacteria (Aphanocapsa, Merismopedia). The zooplankton community was either dominated by large cladocerans and cyclopoid copepods, or by the calanoid copepod Boeckella occidentalis. Total concentrations of phosphorus (P) and nitrogen (N) were comparable to those in temperate mountain lakes (4–35 μg P L−1 and 162–758 μg N L−1) while Chl-a concentrations were in the lower range (<1 μg L−1). A large part of the total nutrient pool consists of dissolved organic N and P that appeared to have a low bioavailability to phytoplankton. The median seston N:P ratio of 44, a positive correlation between Chl-a and total P concentration, as well as nutrient addition assays carried out in three lakes all pointed to P limitation of phytoplankton. © 2016 John Wiley & Sons Ltd
Resumen : 
The tropical Andes has a high density of glacial lakes that are situated in the high-altitude páramo (3500–4500 m). Ecological information about such lakes is scant despite the fact that these lakes are an important source of water for drinking, irrigation and electricity generation and feed several major tributaries of the Amazon. In this study, we provide data on a survey of 31 lakes in Cajas National Park (Ecuador). Two of the lakes were monitored monthly during one year. In situ nutrient addition experiments were carried out in three of the lakes. Seasonal monitoring in two lakes revealed a thermal stratification of the water column between October and June, with a small temperature difference between epi- and hypolimnion (2–3 °C). Oxygen depletion of the hypolimnion towards the end of the stratification period indicated that no complete mixing of the water column occurred during stratification. There was no evidence of depletion of nutrients in the epilimnion or accumulation in the hypolimnion during stratification. There were also no clear seasonal changes in chlorophyll-a (Chl-a) concentration nor in phytoplankton community composition in the two lakes. Inputs of dissolved organic carbon (DOC) from the vegetated catchment resulted in high DOC concentrations (median 2.9 mg L−1) compared to temperate mountain lakes. Water transparency was relatively low, with a median extinction coefficient for photosynthetic active radiation of 0.50 m−1 and for UV-B radiation of 10.13 m−1. Although the thermocline was deep and water transparency was low, estimates of the critical depth for photosynthesis were deeper than the mean water depth in all lakes, suggesting that phytoplankton was not light limited. The phytoplankton community was dominated by chlorophytes (e.g. Oocystis), diatoms (small Cyclotella spp.) or small colonial cyanobacteria (Aphanocapsa, Merismopedia). The zooplankton community was either dominated by large cladocerans and cyclopoid copepods, or by the calanoid copepod Boeckella occidentalis. Total concentrations of phosphorus (P) and nitrogen (N) were comparable to those in temperate mountain lakes (4–35 μg P L−1 and 162–758 μg N L−1) while Chl-a concentrations were in the lower range (<1 μg L−1). A large part of the total nutrient pool consists of dissolved organic N and P that appeared to have a low bioavailability to phytoplankton. The median seston N:P ratio of 44, a positive correlation between Chl-a and total P concentration, as well as nutrient addition assays carried out in three lakes all pointed to P limitation of phytoplankton. © 2016 John Wiley & Sons Ltd
URI : https://onlinelibrary.wiley.com/doi/abs/10.1111/fwb.12878
URI Fuente: https://onlinelibrary.wiley.com/journal/13652427
ISSN : 0046-5070
Aparece en las colecciones: Artículos

Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
documento.pdfdocument793.38 kBAdobe PDFVista previa
Visualizar/Abrir


Este ítem está protegido por copyright original



Los ítems de DSpace están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.

 

Centro de Documentacion Regional "Juan Bautista Vázquez"

Biblioteca Campus Central Biblioteca Campus Salud Biblioteca Campus Yanuncay
Av. 12 de Abril y Calle Agustín Cueva, Telf: 4051000 Ext. 1311, 1312, 1313, 1314. Horario de atención: Lunes-Viernes: 07H00-21H00. Sábados: 08H00-12H00 Av. El Paraíso 3-52, detrás del Hospital Regional "Vicente Corral Moscoso", Telf: 4051000 Ext. 3144. Horario de atención: Lunes-Viernes: 07H00-19H00 Av. 12 de Octubre y Diego de Tapia, antiguo Colegio Orientalista, Telf: 4051000 Ext. 3535 2810706 Ext. 116. Horario de atención: Lunes-Viernes: 07H30-19H00