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El agua habla sin cesar
y nunca se repite
Octavio Paz
General description
Las Madres Lake is an artificial small lake where thermal stratification occurs from April-May and where some interesting meromictic processes are present. Its origin is recent, due to the extraction of gravel and sand from the alluvial plain, whose hole is occupied by the water of the underlying aquifer. The age of the lake is a bit older than 30 years. The gravel exploitation was abandoned in the middle of the 80s. Afterwards, Arganda del Rey (Madrid) Town Council arranged the lake sides and slopes, established a perimeter path and built some facilities for different recreational uses (fishing, rowing, horse riding, etc.), equipping it with a wood pier and some rowing boats. From the middle of the next decade, the Cooperativa de Mujeres COPUMA is responsible for its maintenance and its recreational management.
Actually, it is a complex of lakes, constituted by four pails located along a E-W axis, but the connexion between them is mainly underground. The work that will be described here is developed in the most eastern pail, which is also the biggest one.
Las Madres is located in an area protected from the wind, in its south, south-west and west sides mainly. It lacks of superficial water supply, being the main contribution of underground origin. It is therefore a seepage lake which atmospheric deposition is also very limited. The lake level changes depend on the underlying aquifer oscillations which flows from NNE to SSE in Las Madres environment (Álvarez, 2006). But this level is affected by the exploitation of the near gravel lands: as the open air gravel land surface increases, the water level decreases because the aquifer water (and the close lake water) fills the pail recently created. In Las Madres case, this fact is specially clear due to the opening of a new extensive gravel land in the northern surroundings, which has resulted in an average decline of about 1 meter in the lake level during the last decade.
Fig.1. Batimetric map of the most eastern pail Las Madres lake, where this study is carried out. The deepest zone is located towards the east because the last mineral matter extraction was there. Depths are in metres. The asterisk shows the permanent sampling station. |
Fig.2. Materials inputs in a gravel land that contributes to its eutrophication. There are two types: “external charge”, from outside of the lake, and “internal charge” generated within the ecosystem. Among the external charges there are: from the superficial runoff for the erosion of the close terrestrial ecosystems (CE), from the underground water (CS), from the river by infiltration (CR, it doesn’t exist in Las Madres case) and from the atmosphere (CA). Within the internal charges: nutrients generated by living creatures decomposition, mainly the plankton (CP) and the littoral macrophites (CM), the communities that can get the most biomass.
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Site history
“Since I started working in research, I considered indispensable the existence of long data series regarding the study ecosystems In ecology, I always thought that the existence of experimental stations which systematically record data from their environment, as the Rothamstead Experimental Station (Harpenden, near London, the Freshwater Biological Association (Ambleside in Lake District and East Stoke in Dorset) in England, the Hubbard Brook Experimental Forest (North Woodstock, New Hampshire), the Coweeta Hydrologic Laboratory (Otto, North Carolina) in USA and the Max Planck Institut für Limnologie (Plön in Schleswig-Holstein, Germany) is one of the best means to obtain the necessary information to detect trends in their functioning which the conventional research projects don’t provide. So, when I got a stable research position, one of the goals I established was trying to obtain long-term data about a concrete ecosystem as far as possible. Because of my previous experience in gravel land lakes close to the laboratory, which it made possible – among several things – a quick and comfortable study, I chose the small Las Madres lake and I started the limnological studies in there in 1991, carrying out a monthly monitoring from September 1991 upon now. The study was initially reinforced by the concession, from the Autonomous Community of Madrid, of a quite complete meteorological station that initially was going to be installed on the bank of the lake, but that finally was installed in CSIC lands, 2 km NE from the lake. After that it has not had any other direct funding sources to carry out the monitoring.
(Miguel Álvarez Cobelas, responsible researcher of the station)
Geographical information
LOCATION: Jarama basin, Arganda del Rey Municipality; it is located around the right part of the M-3020 road, km 1,800. At present, it is called “Las Lagunas: Enclave Natural”.
ALTITUDE: 530 m.a.s.l.
COORDINATES: 40º 18’ 10’’ N, 3º 31’ 10’’ W
EXTENSION: Vertical profiles taken in a central buoy in the lake (see Fig.1.)
Maximum length (m) |
355 |
Dissolved oxygen (mg/L) |
0,0-19,5 |
Maximum effective length (m) |
345 |
Conductivity (μS/cm) |
1480-3890 |
Maximum width (m) |
128 |
pH |
4,06-8,41 |
Average width (m) |
100 |
Alkalinity (meq/L) |
3,36-7,95 |
Effective width (m) |
128 |
Dissolved inorganic carbon (mg C/L) |
3,11-24,93 |
Maximum depth (m) |
19 |
Total matter (mg/L) |
1750-4214 |
Average depth (m) |
7,9 |
Matter in suspension (mg/L) |
0,5-84 |
Zave:Zmax |
0,42 |
Silicates (mg Si/L) |
0,09-13,11 |
Relative depth (%) |
88 |
Sulphates (meq/L) |
2,2-45,8 |
Orientation |
SWW-NEE |
Chlorides (meq/L) |
6,7-7,9 |
Perimeter (m) |
1030 |
Calcium (meq/L) |
8,0-13,1 |
Volume (m3) |
283480 |
Magnesium (meq/L) |
8,0-8,3 |
Area (Ha) |
3,58 |
Sodium (meq/L) |
9,2-11,3 |
Volume development |
1,25 |
Potassium (meq/L) |
0,4-0,6 |
Perimeter development |
1,53 |
Nitrates (mg/L) |
0,00-27,40 |
Islands (m2) |
760 |
Nitrites (mg/L) |
0,000-1,267 |
Wind exposition (m) |
146 |
Ammonium (mg/L) |
0,000-2,868 |
Gravity centre (m) |
4,94 |
Total nitrogen (mg N/L) |
0,12-8,46 |
Water temperature (ºC) |
6,4-28,2 |
Ortophosphate (mg/L) |
0,000-0,218 |
Transparency (m) |
0,4-7,2 |
Total phosphorus (mg P/L) |
0,000-1,300 |
Light extinction (m-1) |
0,3-4,6 |
Chlorophyll “a” (μg/L) |
0,1-37,2 |
Table.1. Morphometric characteristics and ranges of the main limnological variables in Las Madres lake for the period 1991-2005. The morphometric parameters follow the definitions of G.E. Hutchinson (1957); the wind exposition has been estimated for the zone of the buoy where the sampling is carried out.
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Contact information
CONTACT PERSON:
Miguel Álvarez Cobelas
INSTITUTION:
Instituto de Recursos Naturales – Centro de Ciencias Medioambientales (CSIC)
ADDRESS:
C/Serrano 115 dpdo.
28006 - Madrid
PHONE: (+34) 91-7452500
E-MAIL: malvarez@ccma.csic.es
WEB: www.humedalesibericos.com
Main biotic community
All of a conventional lake, including plankton and bentos; the work pays mainly attention to plankton, although some studies have been carried out in bentos.
Current research topics
Long-term monitoring.
Current data
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Starting date |
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Abiotic parameters |
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Climate |
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AIR TEMPERATURE |
From 9/1991 |
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WIND SPEED |
From 09/1991 |
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WIND DIRECTION |
From 09/1991 |
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TOTAL INCIDENTAL RADIATION |
From 09/1991 |
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RELATIVE HUMIDITY |
From 09/1991 |
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Hydrology |
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WATER TEMPERATURE |
From 09/1991 |
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TRANSPARENCY |
From 09/1991 |
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PHOTOSYNTHETICALLY ACTIVE RADIATION |
From 09/1991 |
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CONDUCTIVITY |
From 09/1991 |
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DISSOLVED OXYGEN |
From 09/1991 |
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pH |
From 09/1991 |
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TOTAL SOLIDS |
1991-1999 |
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SÓLIDS IN SUSPENSION |
1991-1999 |
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ALKALINITY |
1991-1997 |
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DISSOLVED ORGANIC CARBON |
From
12/1999 |
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SÍLICATES |
1991-1997 |
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SULPHATES |
1991-1997 |
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NITRATES |
From 09/1991 |
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NITRITES |
From 09/1991 |
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AMMONIUM |
From 09/1991 |
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TOTAL NITROGEN |
From 09/1991 |
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ORTOPHOSPHATE |
From 09/1991 |
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TOTAL PHOSPORUS |
From 09/1991 |
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PHYTOPLANKTONIC CHLOROPHYLL “a” |
From 09/1991 |
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Biotic parameters |
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Structural |
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BACTERIAL BIOMASS |
From 09/1991 |
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PHYTOPLANKTON COMPOSITION, DENSITY AND BIOMASS |
From 09/1991 |
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ZOOPLANKTON COMPOSITION, DENSITY AND BIOMASS |
From 08/2002 |
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The samples have been always taken in the same place, one buoy located in the centre of the lake pail, whose depth is about 12 meters, depending on the oscillations of the water level. The frequency of the limnological sampling is monthly. The meteorological records are the average of ten minutes measurements collected in continuous by the sensors.
DATA GUARANTEED ON A LONG-TERM PERSPECTIVE:
Meteorological variables, water transparency, water temperature, conductivity, dissolved oxygen, pH, main compounds of nitrogen and phosphorus and phytoplankton chlorophyll “a”.
DATA FORMAT::
Text files (.txt)
Data access
Data files provided here can be used freely, mentioning and thanking their origin. As a polite gesture, the responsible researcher would be pleased to receive a copy of the publications that make use of this data. For the other variables that not are available in the web (see Current Data Table), people interested in them have to contact Miguel Álvarez Cobelas, with who the use conditions will be accorded.
Facilities
There are some buoys in the lake where it is possible to anchor to take the samples. Moreover, there are some rowing boats which can be used for the sampling. About 2 km NE it is located the Estación Experimental de Energía Solar, belonging to the Instituto de Ciencias de la Construcción (CSIC), where it is located the meteorological station.
Research projects and funding institutions
None.
Main references
Alvarez, M., J.L. Velasco, M. Valladolid, A. Baltanás & C. Rojo. 2005. Daily patterns of mixing and nutrient concentrations during early autumn circulation in a small sheltered lake. Freshwater Biology 50: 813-829.
Alvarez, M. 2006. Groundwater-mediated limnology in Spain. Limnetica 25: 107-122.
Alvarez, M., C. Rojo, J.L. Velasco & A. Baltanás. 2006a. Factors controlling planktonic size spectral responses to autumnal circulation in a Mediterranean lake. Freshwater Biology 51: 131-143.
Alvarez, M., A. Baltanás, J.L. Velasco & C. Rojo. 2006b. Zooplankton dynamics during autumn circulation in a small, wind-sheltered, Mediterranean lake. Marine and Freshwater Research 57: 441-452.
García-Avilés, J. 2002a. Biodiversidad de los humedales del Parque Regional del Sureste. II. Libélulas. Serie Documentos nº 36. Centro de Investigaciones Ambientales de la Comunidad de Madrid “Fernando González Bernáldez”. Madrid. 60 pp.
García-Avilés, J. 2002b. Biodiversidad de los humedales del Parque Regional del Sureste. III. Heterópteros acuáticos. Serie Documentos nº 37. Centro de Investigaciones Ambientales de la Comunidad de Madrid “Fernando González Bernáldez”. Madrid. 62 pp.
García-Avilés, J., N. Roblas & J. Hidalgo. 1999. Biodiversidad de los humedales del Parque Regional del Sureste. I. Vertebrados acuáticos. Serie Documentos nº 29. Consejería de Medio Ambiente. Comunidad Autónoma de Madrid. Madrid. 65 pp.
Gil, M. 1991. Notas sobre plantas acuáticas madrileñas, I. Anales del Jardín Botánico de Madrid 49: 292-293.
Rojo, C. & M. Álvarez. 2001. Phytoplankton structure and dynamics at daily temporal scale: response to the thermal overturn. Archiv für Hydrobiologie 151: 549-569.
Velasco, J.L., M. Alvarez & A. Rubio. 1996. Influencia de la ruptura de la termoclina sobre la comunidad de rotíferos planctónicos de una laguna meromíctica (Las Madres, Madrid). Ecología 10: 523-532.
Acknowledgements
Marcelo Izquierdo and Emilio Martín (Instituto de Ciencias de la Construcción, CSIC, Madrid) have been in charge of the meteorological station maintenance. COMUPA cooperative (located in Arganda del Rey, www.comupa.com), specially Elena Bascuñana and Manuel Ángel Rodríguez Caballero, has facilitated the lake sampling, which is carried out with the Ayuntamiento de Arganda del Rey authorization. Throughout the years, many people have participated in our samplings and analysis: Ángel Rubio, José Luis Velasco, María Valladolid, Oscar Soriano, Ángel Baltanás, Mercedes Arauzo, Julián Vicioso, María Verdugo, Julio Camargo, Salvador Sánchez Carrillo, David Angeler, Palmira Riolobos, Javier García-Avilés, Juana Hidalgo, Youssef Himi, José María Alonso, Eva López Delgado and María José Ortiz.
Some Preliminary analysis
The two first figures above represent the average temperature of water and phytoplanktonic chlorophyll “a” in the mixed layer of Las Madres lake from 1991 to 2005. In principle, it would be expected the climate change to help the phytoplanktonic biomass increase because of the average temperature air increase and, consequently, the water one (it would accelerate the phytoplanctonic metabolism), but any significant relationship between water temperature and chlorophyll has been found (p > 0,05). Moreover, a bigger temperature variability –characteristic that some people consider associated to climate change- doesn’t help neither the chlorophyll increase, as the third figure demonstrates for the study period 1991-2005 (p < 0,05), but the opposite. “Everything is very complicated”, as some football players usually affirm. We will continue informing.
Data available for downloading
The station has available continuous data from 1991 (*except for some punctual moments when the sampling was not possible or when there was any problem with the samples themselves).
| Downloadable files |
Meteorological data: Data is stored in files per years. Each file has a name as “01021223.txt”, that indicates the station number (“01”, it is actually the only one), the year (“02”), the month (“12” December) and the day of the month (“23”).
Data starts to be recorded at 00:00 h and the station calculates averages, maximums and minimums at intervals of 10 minutes. |
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Meteorological data 1991 |
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Meteorological data 1992 |
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Meteorological data 1993 |
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Meteorological data 1994 |
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Meteorological data 1995 |
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Meteorological data 1996 |
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Meteorological data 1997 |
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Meteorological data 1998 |
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Meteorological data 1999 |
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Meteorological data 2000 |
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Meteorological data 2001 |
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Meteorological data 2002 |
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Meteorological data 2003 |
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Meteorological data 2004 |
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Meteorological data 2005 |
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Temperature (1991-2005) |
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Dissolved oxygen (1991-2005) |
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Transparency (1991-2005) |
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ph + Conductivity (1991-2005) |
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Inorganic nitrogen (1991-2005) |
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Ortophosphate (1991-2005) |
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Nitrogen + Total phosphates (1991-2005) |
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Chlorophyll “a” (1991-2005) |
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Temperature” and “Dissolved oxygen” variables have been measured metre by metre deepth every year. Exceptionally, the initial measurement (surface or 0 metres) and the deepest one (-12 metres) can be missing due to oscillations in the lake water level. Almost all the other variables started to be measured metre by metre since the beginning, but in most of the cases from 1994, they have been measured just in the representative depths of the epilimnion (indicated by “E”), the thermocline (in case there was, indicated by “T”) and the monimolimnion (Indicated by “H”). Nitrogen and total phosphates were measured just in these representative depths from the beginning of the monitoring. |
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