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\section{Case Studies}  The data of different lakes models used in this section was obtained using The Aquatic Ecosystem Simulator (Randerson and Bowker, 2008). The model used is deterministic, so there is no variation in different simulation runs. All variables and daily data we obtained from Artick, North1, North2 and Tropical lakes are shown in Anex 1.  \subsection{Artic Lake}  In general, Arctic lake systems are classified as oligotrophic due to their low primary production, represented in chlorophyll values of 0.8-2.1 mg/m3. The lake’s water column, or limnetic zone, is well-mixed; this means that there are no stratifications (layers with different temperatures). During winter (October to March), the surface of the lake is ice covered. During summer (April to September), ice melts and the water flow and evaporation increase, as shown in Figure **. Consequently, the two climatic periods (winter and summer) in the Arctic region cause a typical hydrologic behavior in lakes as the one shown in Figure **.  This hydrologic behavior influences the physiochemical subsystem of the lake.  Table ** and Figure ** show the variables and daily data we obtained from the Arctic lake simulation.  \subsection{North1 Lake}  North1 lake is a lowland eutrophic lake, located in a warm North-Temperate climate (mean Tº of 14ºC). Their primary production expressed in mg/m3 of chlorophyll is around 6.3-19.2. There are four seasons in a year, winter, spring, summer and autumn. In summer, the flow variations (Inflow and outflow fall to 3.5 from 25.2 and retention time increases to 100 days), the lack are lack or absence of seasonal wind and high temperatures (24ºC), causes the water column thermostratification. Stratification is expressed in generation of two layers. At the border of these layers, temperature changes dramatically (24ºC Surface to 20.6 in Planktonic layer, to 17.3 in Benthic layer). Water above and below of thermocline do not mix. The warmer water is near the surface and denser water is near the bottom. In winter, there is no ice covering in the surface. Opposite to the summer when the flow is minimum, in spring and autumn the water column overturns (Retention Time of 14 days and Zone Mixing of 100%), causing increases in conductivity.  In summer, depletions of oxygen at the three layers are more drastic than Artic lakes (below 8.7 mg/lt). Oxygen is directly correlated with the zone mixing, inflow and outflow, and inverse correlated with the others parameters (fig. **), especially with pH and retention time.  Limiting Nutrients in the form of nitrates, silicates and carbon dioxide are above of 90 percent available for phytoplankton in all layers. According with this availability, phytoplankton and periphyton biomass composition is dominated by planktonic (47) and benthic (34.3) diatoms. This way, 100% 100 percent  of zooplankton composition is reached by herbivorous zooplankton and fish community is dominated by benthic fish (67.6). \subsection{North2 Lake} 
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Variables correlations are more seasonal than the N1. It means the period of summer is related with high retention time, higher pH and winter season with the higher levels of oxygen, inflow and outflow and oxygen. However, there is a more strong correlation of benthic and sediment Oxygen.  Limiting Nutrients like nitrates and carbon dioxide are around of 95 percent available for phytoplankton. Phosphates and Silicates show variations and minor percentage of availability. The former around of 80 percent and the second one around 95 all year. Biomass composition is dominated by planktonic (46.7) and benthic (41) diatoms. Zooplankton composition is almost of herbivorous zooplankton (91.4%), (91.4),  but carnivorous zooplankton reaches a little percentage of 8.6. The group of benthic invertebrates appears with the dominance of the detritivores (87.5). Fish community is dominated by benthic fish again but in a high proportion (88.9). \subsection{Tropical Lake}  The Tropical Lake is a  Hyper-eutrophic ecosystem (Chlorophyll > 19.2 mg/lt) located in a moist Tropical climate (North of the equator, near to the tropic of cancer). This has one wet season and one dry season. Higher irradiance conducts to higher temperatures (Mean) and smaller thermal differences between layers. For that reason,  the water column is permanently warm and stratified. As stratification is due to the heat exchange, but is less stable than at higher latitudes, the wind could have great incidence in the mixing of the water column. Thus, intraseasonal variations have an effect in thickness of the mixed layer than other morphometrically similar temperate lakes  (AES, Lewis). The maximum flow of water is in the wet season, and minimum flow is in the dry season. Episodes of heat and mixing, affects the nutrient cycling and plankton dynamics. It is highlighted that primary production in tropical lakes is about twice than higher latitudes. Also, it is known that Nitrogen is the more limiting nutrient.  In this case, there are more equilibrium among species inside phyto and periphyton communities (around 33% 33 percent  for diatoms, green algae and cyanobacteria). Zooplankton populations are dominated by herbivorous (90%), (90),  benthos by detritivores invertebrates (84.4%) (84.4)  and fishes (87%). (87).