Effects of Changing Rainfall on the Limnology of a Mediterranean, Flowthrough‐Seepage Chain of Lakes

Abstract

Relationships between groundwater and lake ecology are often overlooked, but they may be strong, particularly in seepage lakes. As a result, the nature and degree of groundwater effects on lakes are usually neglected. In this study interactions among rainfall, groundwater and surface water and their limnological effects were traced seasonally for two years of changing rainfall in a Spanish flowthrough, seepage lake complex. Cumulative rainfall dictated recharge of groundwater with delays of nine months. Groundwater discharge, in turn, increased surface discharge downstream. Mediated by the geographical setting of lakes, both fluxes impinged on lake water renewal time, but effects of the latter on limnological variables were much stronger at the district scale than at the single lake scale. These waterrenewal effects included the following: decreasing salinity, total phosphorus concentration and phytoplankton biomass and increasing water transparency and total nitrogen concentration as water renewal shortened, the nitrogen effect arising because of nitrate-rich water entering the lakes as groundwater levels rose. This complex response of a Mediterranean lake district to water availability may also be expected in cold temperate lakes as climate change effects become stronger.

Morphological description and ecology of some rare macroalgae in south-central Spanish rivers (Castilla-La Mancha Region)

“…Margalef, 1983;Bellinger & Sigee, 2010) even though its presence has been detected worldwide: Switzerland (Nägeli, 1849) the United States of America (Prescott, 1981), Austria (Sanders & Rott, 2009), United Kingdom (West, 1904;Pentecost, 1991), Ireland (Carter, 1923), Belgium (van Oye & Hubert, 1937), France (Kouwets, 1999), Slovenia (Vrhovsek & al., 2006). Particularly in Spain, O. stratum has been previously reported in Barcelona (Margalef, 1955), Murcia (Aboal, 1991) and in Castilla-La Mancha (Ruidera Lakes) (Álvarez-Cobelas & al., 2007), although we think that it could be a common species in calcareous mountains and springs.…”

“…The rest of region is scarcely studied (e.g. Aboal, 1996;Álvarez & al., 2007) although a species list of Charophytes in Castilla-La Mancha focusing mainly on wetland areas has been published by Cirujano & Medina (2002). Additionally, a recent review on the status of river aquatic plants in this region (Moreno & al., 2011) provides an up to date regional catalogue of aquatic bryophyte species as well as a list of macroalgae genera.…”

Intraspecific variation in sensitivity to food availability and temperature-induced phenotypic plasticity in the rotiferKeratella cochlearis

“…Ruidera National Park is a karst landscape formed by 15 chain-connected lakes with SE-NW flow-through and fed by groundwater. Their mixing dynamics are very rapid because of their small size (Alvarez-Cobelas et al, 2006). When groundwater levels are high, the lakes are fed by surface drainage from upper to lower lakes.…”

Dynamics of the planktonic food web in Colgada Lake (Lagunas de Ruidera Natural Park)

“…Of the 15 interconnected lakes, Colgada Lake, is the most studied. The lake is fed mainly by subterranean waters with a high nitrogen level ( Álvarez-Cobelas et al, 2006b). This lake, together with many other small La Mancha lakes from La Mancha, was previously studied by Armengol et al (1975).…”