Special Issue "Effect of Extreme Climate Events on Lake Ecosystems"

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Water Quality and Contamination".

Deadline for manuscript submissions: closed (31 August 2020) | Viewed by 32527

Special Issue Editors

Prof. Dr. Erik Jeppesen
E-Mail Website
Guest Editor
1. Department of Bioscience, Aarhus University, 8600 Silkeborg, Denmark
2. Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, 06800 Ankara, Turkey
Interests: aquatic ecology; biological structure and interactions with the nutrient dynamics and climate in lakes; lake restoration; lake re-establishment; paleoecology; ecosystem modelling
Special Issues, Collections and Topics in MDPI journals
Dr. Donald C. Pierson
E-Mail Website
Guest Editor
Department of Ecology and Genetics, Limnology, Uppsala University, 75236 Uppsala, Sweden
Interests: mathematical modeling of environmental processes; primary production; underwater optics; sediment resuspension; biogeochemical cycles; surface hydrology, climate change water supply operations
Dr. Eleanor Jennings
E-Mail Website
Guest Editor
Centre for Freshwater and Environmental Studies, Dundalk Institute of Technology, Dundalk, Ireland
Interests: nutrient and carbon cycling in catchments and lakes; modelling of catchment and in-lake processes; climate change impacts on lakes especially effects of extreme climatic events

Special Issue Information

Dear Colleagues,

The impacts of extreme weather events on lakes have received increasing attention in recent years. This is because the severity and frequency of such events have increased and are predicted to increase even further in the years to come due to ongoing climate change. Furthermore, advances in real-time high-resolution monitoring now make it possible to track even the short-term effects of such events. Episodic events may potentially have strong effects on lake ecosystems in the short-term and, if severe, also on the longer term. This Special Issue welcomes contributions on the effects of extreme weather events on lake ecosystems, such as change in precipitation leading, for example, to changes in nutrient and dissolved organic carbon (DOC) loading and salinity, or how heatwaves and changes in the intensity and frequency of winds affect both stratification and the biological community and processes. We also welcome contributions on how hurricanes may lead to immediate and long-lasting changes in lake ecosystems, as well as papers dealing with resistance and resilience to extreme events or showing sudden regime shifts.

Prof. Dr. Erik Jeppesen
Dr. Donald C. Pierson
Dr. Eleanor Jennings
Guest Editors

Manuscript Submission Information

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Keywords

  • extreme weather events
  • lakes
  • effect on hydrodynamics
  • nutrients and ecology
  • resistance and resilience
  • regime shifts
  • climate change

Published Papers (13 papers)

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Editorial

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Editorial
Effect of Extreme Climate Events on Lake Ecosystems
Water 2021, 13(3), 282; https://doi.org/10.3390/w13030282 - 25 Jan 2021
Cited by 8 | Viewed by 2473
Abstract
The Earth is facing a major change in climate due to ongoing global warming [...] Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)

Research

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Article
Nutrient Loading, Temperature and Heat Wave Effects on Nutrients, Oxygen and Metabolism in Shallow Lake Mesocosms Pre-Adapted for 11 Years
Water 2021, 13(2), 127; https://doi.org/10.3390/w13020127 - 07 Jan 2021
Cited by 10 | Viewed by 2100
Abstract
Global changes (e.g., warming and population growth) affect nutrient loadings and temperatures, but global warming also results in more frequent extreme events, such as heat waves. Using data from the world’s longest-running shallow lake experimental mesocosm facility, we studied the effects of different [...] Read more.
Global changes (e.g., warming and population growth) affect nutrient loadings and temperatures, but global warming also results in more frequent extreme events, such as heat waves. Using data from the world’s longest-running shallow lake experimental mesocosm facility, we studied the effects of different levels of nutrient loadings combined with varying temperatures, which also included a simulated 1-month summer heat wave (HW), on nutrient and oxygen concentrations, gross ecosystem primary production (GPP), ecosystem respiration (ER), net ecosystem production (NEP) and bacterioplankton production (BACPR). The mesocosms had two nutrient levels (high (HN) and low (LN)) combined with three different temperatures according to the IPCC 2007 warming scenarios (unheated, A2 and A2 + 50%) that were applied for 11 years prior to the present experiment. The simulated HW consisted of 5 °C extra temperature increases only in the A2 and A2 + 50% treatments applied from 1 July to 1 August 2014. Linear mixed effect modeling revealed a strong effect of nutrient treatment on the concentration of chlorophyll a (Chl-a), on various forms of phosphorus and nitrogen as well as on oxygen concentration and oxygen percentage (24 h means). Applying the full dataset, we also found a significant positive effect of nutrient loading on GPP, ER, NEP and BACPR, and of temperature on ER and BACPR. The HW had a significant positive effect on GPP and ER. When dividing the data into LN and HN, temperature also had a significant positive effect on Chl-a in LN and on orthophosphate in HN. Linear mixed models revealed differential effects of nutrients, Chl-a and macrophyte abundance (PVI) on the metabolism variables, with PVI being particularly important in the LN mesocosms. All metabolism variables also responded strongly to a cooling-low irradiance event in the middle of the HW, resulting in a severe drop in oxygen concentrations, not least in the HN heated mesocosms. Our results demonstrate strong effects of nutrients as well as an overall rapid response in oxygen metabolism and BACPR to changes in temperature, including HWs, making them sensitive ecosystem indicators of climate warming. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Impact of Nutrients, Temperatures, and a Heat Wave on Zooplankton Community Structure: An Experimental Approach
Water 2020, 12(12), 3416; https://doi.org/10.3390/w12123416 - 04 Dec 2020
Cited by 14 | Viewed by 2424
Abstract
Shallow lakes are globally the most numerous water bodies and are sensitive to external perturbations, including eutrophication and climate change, which threaten their functioning. Extreme events, such as heat waves (HWs), are expected to become more frequent with global warming. To elucidate the [...] Read more.
Shallow lakes are globally the most numerous water bodies and are sensitive to external perturbations, including eutrophication and climate change, which threaten their functioning. Extreme events, such as heat waves (HWs), are expected to become more frequent with global warming. To elucidate the effects of nutrients, warming, and HWs on zooplankton community structure, we conducted an experiment in 24 flow-through mesocosms (1.9 m in diameter, 1.0 m deep) imitating shallow lakes. The mesocosms have two nutrient levels (high (HN) and low (LN)) crossed with three temperature scenarios based on the Intergovernmental Panel on Climate Change (IPCC) projections of likely warming scenarios (unheated, A2, and A2 + 50%). The mesocosms had been running continuously with these treatments for 11 years prior to the HW simulation, which consisted of an additional 5 °C increase in temperature applied from 1 July to 1 August 2014. The results showed that nutrient effects on the zooplankton community composition and abundance were greater than temperature effects for the period before, during, and after the HW. Before the HW, taxon richness was higher, and functional group diversity and evenness were lower in HN than in LN. We also found a lower biomass of large Cladocera and a lower zooplankton: phytoplankton ratio, indicating higher fish predation in HN than in LN. Concerning the temperature treatment, we found some indication of higher fish predation with warming in LN, but no clear effects in HN. There was a positive nutrient and warming interaction for the biomass of total zooplankton, large and small Copepoda, and the zooplankton: phytoplankton ratio during the HW, which was attributed to recorded HW-induced fish kill. The pattern after the HW largely followed the HW response. Our results suggest a strong nutrient effect on zooplankton, while the effect of temperature treatment and the 5 °C HW was comparatively modest, and the changes likely largely reflected changes in predation. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Phytoplankton Community Response to Nutrients, Temperatures, and a Heat Wave in Shallow Lakes: An Experimental Approach
Water 2020, 12(12), 3394; https://doi.org/10.3390/w12123394 - 02 Dec 2020
Cited by 18 | Viewed by 2664
Abstract
Phytoplankton usually responds directly and fast to environmental fluctuations, making them useful indicators of lake ecosystem changes caused by various stressors. Here, we examined the phytoplankton community composition before, during, and after a simulated 1-month heat wave in a mesocosm facility in Silkeborg, [...] Read more.
Phytoplankton usually responds directly and fast to environmental fluctuations, making them useful indicators of lake ecosystem changes caused by various stressors. Here, we examined the phytoplankton community composition before, during, and after a simulated 1-month heat wave in a mesocosm facility in Silkeborg, Denmark. The experiment was conducted over three contrasting temperature scenarios (ambient (A0), Intergovernmental Panel on Climate Change A2 scenario (circa +3 °C, A2) and A2+ %50 (circa +4.5 °C, A2+)) crossed with two nutrient levels (low (LN) and high (HN)) with four replicates. The facility includes 24 mesocosms mimicking shallow lakes, which at the time of our experiment had run without interruption for 11 years. The 1-month heat wave effect was simulated by increasing the temperature by 5 °C (1 July to 1 August) in A2 and A2+, while A0 was not additionally heated. Throughout the study, HN treatments were mostly dominated by Cyanobacteria, whereas LN treatments were richer in genera and mostly dominated by Chlorophyta. Linear mixed model analyses revealed that high nutrient conditions were the most important structuring factor, which, regardless of temperature treatments and heat waves, increased total phytoplankton, Chlorophyta, Bacillariophyta, and Cyanobacteria biomasses and decreased genus richness and the grazing pressure of zooplankton. The effect of temperature was, however, modest. The effect of warming on the phytoplankton community was not significant before the heat wave, yet during the heat wave it became significant, especially in LN-A2+, and negative interaction effects between nutrient and A2+ warming were recorded. These warming effects continued after the heat wave, as also evidenced by Co-inertia analyses. In contrast to the prevailing theory stating that more diverse ecosystems would be more stable, HN were less affected by the heat wave disturbance, most likely because the dominant phytoplankton group cyanobacteria is adapted to high nutrient conditions and also benefits from increased temperature. We did not find any significant change in phytoplankton size diversity, but size evenness decreased in HN as a result of an increase in the smallest and largest size classes simultaneously. We conclude that the phytoplankton community was most strongly affected by the nutrient level, but less sensitive to changes in both temperature treatments and the heat wave simulation in these systems, which have been adapted for a long time to different temperatures. Moreover, the temperature and heat wave effects were observed mostly in LN systems, indicating that the sensitivity of phytoplankton community structure to high temperatures is dependent on nutrient availability. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
From Highs to Lows: Changes in Dissolved Organic Carbon in a Peatland Catchment and Lake Following Extreme Flow Events
Water 2020, 12(10), 2843; https://doi.org/10.3390/w12102843 - 13 Oct 2020
Cited by 6 | Viewed by 2122
Abstract
The concentration of dissolved organic carbon (DOC) in freshwater catchments has implications for carbon availability in downstream lakes and for water supplies. The links between catchment hydrology and stream and lake DOC concentrations are, however, still not fully understood. Much of the literature [...] Read more.
The concentration of dissolved organic carbon (DOC) in freshwater catchments has implications for carbon availability in downstream lakes and for water supplies. The links between catchment hydrology and stream and lake DOC concentrations are, however, still not fully understood. Much of the literature has been from catchments with organo-mineral soils, with fewer studies from upland peat sites. We used high-frequency fluorescence data, a proxy for DOC, to investigate 1. the relationship between stream discharge and concentration in a blanket peat catchment during extreme high flows and 2. the relationship between inflow and in-lake estimated DOC concentrations. We found that for approximately two thirds of extreme events, there was a decrease in stream DOC concentration (i.e., a dilution) on the rising limb rather than an increase (i.e., a flushing out of DOC from terrestrial stores). Flushing events dominated only in summer when concentrations in the stream were also increasing. In comparison to the stream, concentrations in the downstream lake were less variable, and peaks and troughs were damped and lagged. Replicating these patterns and processes in DOC models would be critical in order to provide appropriate simulations in response to shorter- and longer-term changes in climate, and thus inform future catchment and lake management. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Impacts of Extreme Weather Events on Bacterial Community Composition of a Temperate Humic Lake
Water 2020, 12(10), 2757; https://doi.org/10.3390/w12102757 - 03 Oct 2020
Cited by 6 | Viewed by 2192
Abstract
Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this [...] Read more.
Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this study was to use high-throughput sequencing to explore the bacterial community composition of a humic oligotrophic lake on the North Atlantic Irish coast and to assess the impacts on composition dynamics related to extreme weather events. Samples for sequencing were collected from Lough Feeagh on a fortnightly basis from April to November 2018. Filtration was used to separate free-living and particle-associated bacterial communities and amplicon sequencing was performed for the 16S rRNA V4 region. Two named storms, six high discharge events, and one drought period occurred during the sampling period. These events had variable, context-dependent effects on bacterial communities in Lough Feeagh. The particle-associated community was found to be more likely to respond to physical changes, such as mixing, while the free-living population responded to changes in nutrient and carbon concentrations. Generally, however, the high stability of the bacterial community observed in Lough Feeagh suggests that the bacterial community is relatively resilient to extreme weather events. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Ensemble Modeling of the Impact of Climate Warming and Increased Frequency of Extreme Climatic Events on the Thermal Characteristics of a Sub-Tropical Lake
Water 2020, 12(7), 1982; https://doi.org/10.3390/w12071982 - 13 Jul 2020
Cited by 18 | Viewed by 1715
Abstract
Lake ecosystems are impacted by changes in climatic conditions. Climate changes forecasted to occur are reflected in models by slow gradual changes over extended periods of time. Output from weather generators, on the other hand, can simulate short-term extreme conditions and weather patterns. [...] Read more.
Lake ecosystems are impacted by changes in climatic conditions. Climate changes forecasted to occur are reflected in models by slow gradual changes over extended periods of time. Output from weather generators, on the other hand, can simulate short-term extreme conditions and weather patterns. In order to evaluate the likely impact of climate changes on a large sub-tropical lake, specifically the thermal regime of the lake, we constructed climate scenarios using a weather generator. The 30-year scenarios included no change in climate conditions, a gradual change, increased frequency of heat waves and a merging of the latter two. The projected impact on the lake’s physical properties was evaluated using an ensemble of 1-D hydrodynamic lake models. The gradual increase scenario had the largest impact on annual temperatures and stratification period; however, increased heat waves had a large effect on the summer lake conditions and introduced a larger degree of variability in water temperature. The use of the ensemble of models resulted in variability in the projected impacts; yet, the large degree of similarity between projected trends and patterns increased confidence in the results. The projected effect the heat waves will have on the lake conditions highlights the need to include heat waves in climate studies and the need for impact studies in order to better understand possible consequences for lake ecosystems. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Differences in the Effects of Storms on Dissolved Organic Carbon (DOC) in Boreal Lakes during an Early Summer Storm and an Autumn Storm
Water 2020, 12(5), 1452; https://doi.org/10.3390/w12051452 - 20 May 2020
Cited by 6 | Viewed by 1721
Abstract
In boreal lakes, increased precipitation events have been linked to increased concentrations of dissolved organic carbon (DOC), however the effects of seasonal differences on DOC and how this may impact storm response remain unclear. We evaluated DOC concentration and a set of DOC [...] Read more.
In boreal lakes, increased precipitation events have been linked to increased concentrations of dissolved organic carbon (DOC), however the effects of seasonal differences on DOC and how this may impact storm response remain unclear. We evaluated DOC concentration and a set of DOC quality metrics during an early summer storm and an autumn storm on a suite of six lakes in Acadia National Park in Maine, USA. to better understand differences in seasonal storm responses. Our results revealed differences in the response of DOC quality metrics to an early summer versus an autumn storm, with changes in DOC quality metrics varying by storm and lake features. During the early summer storm, we observed greater changes in various DOC quality metrics in deep lakes with longer residence times, whereas during the autumn storm, lakes with large watershed area to lake area ratios experienced the greatest changes. Land cover was highly correlated with changing DOC quality metrics in the early summer storm but did not play a significant role in the autumn storm response. Our research provides evidence of seasonal differences in the effects of storms on boreal lakes, which are ultimately mediated by a combination of lake and watershed characteristics as well as seasonal differences in climate such as solar radiation and antecedent weather conditions. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Effects of Consecutive Extreme Weather Events on a Temperate Dystrophic Lake: A Detailed Insight into Physical, Chemical and Biological Responses
Water 2020, 12(5), 1411; https://doi.org/10.3390/w12051411 - 15 May 2020
Cited by 12 | Viewed by 3021
Abstract
Between May and July 2018, Ireland experienced an exceptional heat wave, which broke long-term temperature and drought records. These calm, stable conditions were abruptly interrupted by a second extreme weather event, Atlantic Storm Hector, in late June. Using high-frequency monitoring data, coupled with [...] Read more.
Between May and July 2018, Ireland experienced an exceptional heat wave, which broke long-term temperature and drought records. These calm, stable conditions were abruptly interrupted by a second extreme weather event, Atlantic Storm Hector, in late June. Using high-frequency monitoring data, coupled with fortnightly biological sampling, we show that the storm directly affected the stratification pattern of Lough Feeagh, resulting in an intense mixing event. The lake restabilised quickly after the storm as the heatwave continued. During the storm there was a three-fold reduction in Schmidt stability, with a mixed layer deepening of 9.5 m coinciding with a two-fold reduction in chlorophyll a but a three-fold increase in total zooplankton biomass. Epilimnetic respiration increased and net ecosystem productivity decreased. The ratio of total nitrogen:total phosphorus from in-lake versus inflow rivers was decoupled, leading to a cascade effect on higher trophic levels. A step change in nitrogen:phosphorus imbalances suggested that the zooplankton community shifted from phosphorus to nitrogen nutrient constraints. Such characterisations of both lake thermal and ecological responses to extreme weather events are relatively rare but are crucial to our understanding of how lakes are changing as the impacts of global climate change accelerate. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
13 Years of Storms: An Analysis of the Effects of Storms on Lake Physics on the Atlantic Fringe of Europe
Water 2020, 12(2), 318; https://doi.org/10.3390/w12020318 - 21 Jan 2020
Cited by 15 | Viewed by 2352
Abstract
While winter storms are generally common in western Europe, the rarer summer storms may result in more pronounced impacts on lake physics. Using long-term, high frequency datasets of weather and lake thermal structure from the west of Ireland (2005 to 2017), we quantified [...] Read more.
While winter storms are generally common in western Europe, the rarer summer storms may result in more pronounced impacts on lake physics. Using long-term, high frequency datasets of weather and lake thermal structure from the west of Ireland (2005 to 2017), we quantified the effects of storms on the physical conditions in a monomictic, deep lake close to the Atlantic Ocean. We analysed a total of 227 storms during the stratified (May to September, n = 51) and non-stratified (November to March, n = 176) periods. In winter, as might be expected, changes were distributed over the entire water column, whereas in summer, when the lake was stratified, storms only impacted the smaller volume above the thermocline. During an average summer (May–September) storm, the lake number dropped by an order of magnitude, the thermocline deepened by an average of 2.8 m, water column stability decreased by an average of 60.4 j m−2 and the epilimnion temperature decreased by a factor of five compared to the average change in winter (0.5 °C vs. 0.1 °C). Projected increases in summer storm frequency will have important implications for lake physics and biological pathways. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Glacial Lake Outburst Flood (GLOF) Events and Water Response in A Patagonian Fjord
Water 2020, 12(1), 248; https://doi.org/10.3390/w12010248 - 16 Jan 2020
Cited by 7 | Viewed by 3899
Abstract
As a result of climate change, the frequency of glacial lake outburst floods (GLOF) is increasing in Chilean Patagonia. Yet, the impacts of the flood events on the physics and biology of fjords is still unknown. Current velocities, density, in-situ zooplankton samples, and [...] Read more.
As a result of climate change, the frequency of glacial lake outburst floods (GLOF) is increasing in Chilean Patagonia. Yet, the impacts of the flood events on the physics and biology of fjords is still unknown. Current velocities, density, in-situ zooplankton samples, and volume backscatter (Sv) derived from an acoustic profiler were used to explore the response of circulation and zooplankton abundance in a Patagonian fjord to GLOF events in 2010 and 2014. Maximum Sv was found both during the GLOFs and in late winter to early spring of 2010 and the fall and summer of 2014. The increase in Sv in late winter and spring of 2010 corresponded to multiple zooplankton species found from in-situ net sampling. In addition, diel vertical migrations were found during this seasonal increase both qualitatively and in a spectral analysis. Concurrently with zooplankton increases, wind forcing produced a deepening of the pycnocline. Zooplankton abundance peaked in the fjord when the pycnocline depth deepened due to wind forcing and throughout the entire spring season, indicating that mixing conditions could favor secondary production. These results were corroborated by the 2014 data, which indicate that weather events in the region impact both fjord physics and ecology. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Modeling the Ecological Response of a Temporarily Summer-Stratified Lake to Extreme Heatwaves
Water 2020, 12(1), 94; https://doi.org/10.3390/w12010094 - 26 Dec 2019
Cited by 14 | Viewed by 2859
Abstract
Climate extremes, which are steadily increasing in frequency, can have detrimental consequences for lake ecosystems. We used a state-of-the-art, one-dimensional, hydrodynamic-ecosystem model [General Ocean Turbulence Model (GOTM)-framework for aquatic biogeochemical models (FABM)-PCLake] to determine the influence of extreme climate events on a temperate [...] Read more.
Climate extremes, which are steadily increasing in frequency, can have detrimental consequences for lake ecosystems. We used a state-of-the-art, one-dimensional, hydrodynamic-ecosystem model [General Ocean Turbulence Model (GOTM)-framework for aquatic biogeochemical models (FABM)-PCLake] to determine the influence of extreme climate events on a temperate and temporarily summer stratified lake (Lake Bryrup, Denmark). The model was calibrated (eight years data) and validated (two years data), and the modeled variables generally showed good agreement with observations. Then, a span of extreme warming scenarios was designed based on weather data from the heatwave seen over northern Europe in May–July 2018, mimicking situations of extreme warming returning every year, every three years, and every five years in summer and all year round, respectively. We found only modest impacts of the extreme climate events on nutrient levels, which in some scenarios decreased slightly when looking at the annual mean. The most significant impacts were found for phytoplankton, where summer average chlorophyll a concentrations and cyanobacteria biomass peaks were up to 39% and 58% higher than during baseline, respectively. As a result, the phytoplankton to nutrient ratios increased during the heat wave experiments, reflecting an increased productivity and an increased cycling of nutrients in the pelagic. The phytoplankton blooms occurred up to 15 days earlier and lasted for up to half a month longer during heat wave years relative to the baseline. Our extreme scenarios illustrated and quantified the large impacts of a past heat wave (observed 2018) and may be indicative of the future for many temperate lakes. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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Article
Species-Specific Responses of Submerged Macrophytes to Simulated Extreme Precipitation: A Mesocosm Study
Water 2019, 11(6), 1160; https://doi.org/10.3390/w11061160 - 02 Jun 2019
Cited by 7 | Viewed by 2078
Abstract
More frequent extreme climate events (e.g., extreme precipitation) are to be expected in the future, and such events may potentially have significant effects on freshwater ecosystems. In the present mesocosm study, the effects of simulated extreme precipitation on submerged macrophytes were evaluated for [...] Read more.
More frequent extreme climate events (e.g., extreme precipitation) are to be expected in the future, and such events may potentially have significant effects on freshwater ecosystems. In the present mesocosm study, the effects of simulated extreme precipitation on submerged macrophytes were evaluated for three different macrophyte community (MC) treatments (MC1, MC2 and MC3). MC1 consisted of only Vallisneria denseserrulata, while MC2 and MC3 included three and six species of various growth forms. Two treatments of extreme precipitation (EP) were simulated—an extreme treatment (E) simulating a sudden increase of water level from 75 cm to 150 cm within one day and a gradual treatment (G) simulating an increase to the same water level within 3 months, combined with two control treatments. Total macrophyte community biomass was resilient to the EP and MC treatments, while species-specific variations in responses, in terms of biomass, maximum height, and sexual reproduction, were found. For instance, E led to earlier flowering of Potamogeton lucens and production of more flowers, while it had adverse effects on the flowering of Ottelia alismoides. We conclude that freshwater ecosystems with high coverage of submerged macrophytes may be overall resilient to extreme precipitation under nutrient-limited conditions, especially communities with diverse growth forms. Full article
(This article belongs to the Special Issue Effect of Extreme Climate Events on Lake Ecosystems)
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