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We constructed a model chain into which regional climate-related variables (air temperature, precipitation) and a lake’s main tributary hydrological indicators (river flow, dissolved inorganic carbon) were employed for predicting the evolution of planktonic blue-green algae (cyanobacteria) and zooplankton (rotifer) biomass in that lake for the mid-21st century. Simulations were based on the future climate predicted under both the Representative Concentration Pathways 4.5 and 8.5 scenarios which, combined with three realistic policy-making and basin land-use evolution lead to six scenarios for future water quality. Model outputs revealed that mean annual river flow is expected to decline between 3 to 20%, depending of the scenario. Concentration of river dissolved inorganic carbon is predicted to follow the opposite trend and might soar up to twice the 2005-2014 average concentration. Lake planktonic primary producers will display quantitative changes in the future decades whereas zooplankters will not. A 2 to 10% increase in mean cyanobacteria biomass is accompanied by a stagnation (-3 to +2%) of rotifer biomass. Changes in cyanobacteria and rotifer phenology are expected: a surge of cyanobacteria biomass in winter and a shortening of the rotifer biomass spring peak. The expected quantitative changes on the biota were magnified in those scenarios where forested area conversion to cropland and water abstraction were the greatest.
Content may be subject to copyright.
Fabien Cremona
1
&Sirje Vilbaste
1
&
Raoul-Marie Couture
2,3
&Peeter Nõges
1
&Tiina Nõges
1
Received: 30 August 2016 / Accepted: 22 December 2016 /Published online: 6 January 2017
#Springer Science+Business Media Dordrecht 2017
Abstract We constructed a model chain into which regional climate-related variables (air
temperature, precipitation) and a lakes main tributary hydrological indicators (river flow,
dissolved inorganic carbon) were employed for predicting the evolution of planktonic blue-
green algae (cyanobacteria) and zooplankton (rotifer) biomass in that lake for the mid-21st
century. Simulations were based on the future climate predicted under both the Representative
Concentration Pathways 4.5 and 8.5 scenarios which, combined with three realistic policy-
making and basin land-use evolution lead to six scenarios for future water quality. Model
outputs revealed that mean annual river flow is expected to decline between 3 and 20%,
depending on the scenario. Concentration of river dissolved inorganic carbon is predicted to
follow the opposite trend and might soar up to twice the 20052014 average concentration.
Lake planktonic primary producers will display quantitative changes in the future decades
whereas zooplankters will not. A 2 to 10% increase in mean cyanobacteria biomass is
accompanied by a stagnation (3 to +2%) of rotifer biomass. Changes in cyanobacteria and
rotifer phenology are expected: a surge of cyanobacteria biomass in winter and a shortening of
the rotifer biomass spring peak. The expected quantitative changes on the biota were magni-
fied in those scenarios where forested area conversions to cropland and water abstraction were
the greatest.
Climatic Change (2017) 141:347361
DOI 10.1007/s10584-016-1894-8
Electronic supplementary mat erial The online version of this article (doi:10.1007/s10584-016-1894-8)
contains supplementary material, which is available to authorized users.
*Fabien Cremona
fabien.cremona@emu.ee
1
Centre for Limnology, Institute of Agricultural and Environmental Sciences, Estonian University of
Life Sciences, Kreutzwaldi 5, 51014 Tartu, Estonia
2
Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo, Norway
3
Ecohydrology Research Group, Water Institute and Departmentof Earth and Environmental Sciences,
University of Waterloo, Waterloo, ON N2L 3G1, Canada
Is the future of large shallow lakes blue-green? Comparing
the response of a catchment-lake model chain to climate
predictions
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... As it is located in an area of flat relief the water outflow is restricted and the lake exhibits strong seasonal water level fluctuations with a maximal amplitude of 3.2 m during the snow melt (Cremona et al., 2018;Nõges et al., 2018). About half of the water in Lake Võrtsjärv comes from the river Väike-Emajõgi, which still possesses its natural flow regime (Cremona et al., 2017). The main land use in the basin is agriculture, therefore extensive nutrient inputs since 1961 facilitate high phytoplankton biomass, to which cyanobacteria contribute 60% to 95% (Cremona et al., 2018;Nõges et al., 2018). ...
... Precipitation data were obtained by averaging two time-series from Valga and Tõlliste stations. River flow of Väike Emajõgi, temperature and dissolved inorganic carbon fluxes were used for BRT modeling to obtain future chlorophyll-a concentrations of Lake Võrtsjärv (Cremona et al., 2017). ...
... The scenario downscaling was based on expert judgement, therefore the different implementations by the case studies represent plausible futures, but assessing their uncertainties remains difficult (e.g. Cremona et al., 2017;Hutchins et al., 2018). ...
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There are infinite possible future scenarios reflecting the impacts of anthropogenic multiple stress on our planet. These impacts include changes in climate and land cover, to which aquatic ecosystems are especially vulnerable. To assess plausible developments of the future state of European surface waters, we considered two climate scenarios and three storylines describing land use, management and anthropogenic development (‘Consensus’, ‘Techno’ and ‘Fragmented’, which in terms of environmental protection represent best-, intermediate- and worst-case, respectively). Three lake and four river basins were selected, representing a spectrum of European conditions through a range of different human impacts and climatic, geographical and biological characteristics. Using process-based and empirical models, freshwater total nitrogen, total phosphorus and chlorophyll-a concentrations were projected for 2030 and 2060. Under current conditions, the water bodies mostly fail good ecological status. In future predictions for the Techno and Fragmented World, concentrations further increased, while concentrations generally declined for the Consensus World. Furthermore, impacts were more severe for rivers than for lakes. Main pressures identified were nutrient inputs from agriculture, land use change, inadequately managed water abstractions and climate change effects. While the basins in the Continental and Atlantic regions were primarily affected by land use changes, in the Mediterranean/Anatolian the main driver was climate change. The Boreal basins showed combined impacts of land use and climate change and clearly reflected the climate-induced future trend of agricultural activities shifting northward. The storylines showed positive effects on ecological status by classical mitigation measures in the Consensus World (e.g. riparian shading), technical improvements in the Techno World (e.g. increasing wastewater treatment efficiency) and agricultural extensification in the Fragmented World. Results emphasize the need for implementing targeted measures to reduce anthropogenic impacts and the importance of having differing levels of ambition for improving the future status of water bodies depending on the societal future to be expected.
... However, processes controlling increased cyanobacteria and possible interactions between NO 3 − loadings from the catchment and lake temperature remain unclear. Despite some recent progress (Cremona et al., 2017), more investigation is needed to understand responses of biota to changes in the catchment, such as increased N-rich fertilizer applications or, as observed in Estonia (Sagris and Palo, 2018;Ceccherini et al., 2020), the conversion of forests to agriculture. Võrtsjärv has benefited from decades of high-quality, highresolution monitoring of limnological parameters, so it is an ideal system for time series modelling and predictive scenario construction. ...
... Located in the hemiboreal biome, Võrtsjärv is ice-covered 135 days per year on average. Four main tributaries flow into Võrtsjärv, with the principal one (Väike Emajõgi River) accounting for 40% of the total inflow (Cremona et al., 2017). Other tributaries include Õhne, Tänassilma, and Tarvastu rivers and several other streams and drainage ditches. ...
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... Environments 2020, 7, 77 2 of 25 Several models have been developed to describe the mechanisms involved in bloom onset, development, maintenance and decline, including ecological models based on phytoplankton growth response mechanisms [11][12][13][14], and hydrological models involving nutrient production, transport, and accumulation [15]. Other studies have focused on the relationships between the development of phytoplankton blooms and the environmental conditions prevailing in water bodies or watersheds [16][17][18]. Among others, Hu et al. [19] and Liu et al. [20] have demonstrated the impact of climatic variables (air temperature, relative humidity, wind speed and direction) on the development of cyanobacterial blooms. ...
... For example, this was demonstrated from the analysis of cyanobacterial pigments in sediment cores from over one hundred lakes of Northern America and Europe [71]. Our study allowed to quantify phenological trends over time and with respect to landscape characteristics, promoting predictive models such as the one put forward by Cremona et al. [17], who developed a cyanobacterial biomass prediction model with respect to regional climatic variables and hydrological indicators. They found that cyanobacteria biomass will increase from 2% to 10% in future decades. ...
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... The model was calibrated for the 5-year period with streamflow observations(2011)(2012)(2013)(2014)(2015) using a combination of manual and automatic calibration techniques. Manual calibration has been proven as a robust method for obtaining acceptable simulations within the Integrated Catchment (INCA) family of models(Cremona, Vilbaste, Couture, Nõges, & Nõges, 2017;Futter et al., 2014;Ledesma, Köhler, & Futter, 2012), of which PERSiST is the common hydrological model. An initial manual calibration employing sensible values and thresholds based on expert judgement was used to approximate the dynamics and magnitude of the simulated streamflow to those of the observed streamflow. ...
... discussed byO'Driscoll et al. (2018), climate impact assessment studies, such as the one presented here, can be interpreted in qualitative terms based on alternative scenarios of internally consistent narratives, or "storylines," which are based on a restricted set of possible sources of uncertainty and thus are representations of a subset of all possible futures(Cremona et al., 2017;van Vuuren, Vries, Beusen, & Heuberger, 2008). In our case, combining an educated selection of critical streamflow thresholds based on hydrological observations and C. arnoldi ecological requirements, with moderate F I G U R E 7 Scatter plots of "flow difference in consecutive days" (Q diff ), versus daily precipitation for (a) the whole year and (b) the dry season (April to September) for future Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5 and for the reference period. ...
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... RCP-4.5) and extreme (RCP-8.5) climate scenarios has been employed in ecological studies to contribute to a dialogue about possible futures (Cremona et al., 2017). Similar results have been presented elsewhere for boreal waters (Oni et al., 2015b). ...
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... Warmer winter temperatures could allow cyanobacteria to live and be photosynthetically active year-round, and trigger CyanoHABs earlier in the year when warmer temperatures and nutrients are introduced during the spring, typically referred to as Spring Bloom in southeast U.S. Warmer winter conditions lack the ''natural predation" of a colder, harsher winter and may create environments at elevated risk for CyanoHABs. Global warming and climate change are expected to disproportionately impact winter temperatures (Piao et al., 2010) and cause a surge in winter-time cyanobacteria biomass (Cremona et al., 2017), potentially explaining the importance of winter maximum temperatures. Although the NLCD model had a higher adjusted R-squared value, it is important to note that its classification was less accurate than that of the NAIP. ...
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... These models are capable of predicting future conditions outside the range of data-driven empirical models, projecting the effects of climate, land use, or population changes to inform future-proof mitigation measures (e.g., Wright et al., 2017). The model outputs primarily encompass hydrological or water quality variables, with biological receptors often being linked through empirical modeling (e.g., Stefanidis et al., 2016;Cremona et al., 2017). ...
Chapter
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According to the Intergovernmental Panel on Climate Change report released in September 2014, unprecedented changes in temperature and precipitation patterns have been recorded globally in recent decades and further change is predicted to occur in the near future, mainly as the result of human activity. In particular, projections show that the Mediterranean climate zone will be markedly affected with significant implications for lake water levels and salinity. This may be exacerbated by increased demands for irrigation water. Based on long-term data from seven lakes and reservoirs covering a geographical gradient of 52� of latitudes and a literature review, we discuss how changes in water level and salinity related to climate change and water abstraction affect the ecosystemstructure, function, biodiversity and ecological state of lakes and reservoirs. We discuss mitigationmeasures to counteract the negative effects on ecological status that are likely to result from changes in climate and water abstraction practices. Finally, we highlight research required to improve knowledge of the impacts of anthropogenically induced changes on lake water level and consequent changes in salinity.
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According to the Intergovernmental Panel on Climate Change report released in September 2014, unprecedented changes in temperature and precipitation patterns have been recorded globally in recent decades and further change is predicted to occur in the near future, mainly as the result of human activity. In particular, projections show that the Mediterranean climate zone will be markedly affected with significant implications for lake water levels and salinity. This may be exacer-bated by increased demands for irrigation water. Based on long-term data from seven lakes and reservoirs covering a geographical gradient of 52° of latitudes and a literature review, we discuss how changes in water level and salinity related to climate change and water abstrac-tion affect the ecosystem structure, function, biodiversity and ecological state of lakes and reservoirs. We discuss mitigation measures to counteract the negative effects on ecological status that are likely to result from changes in climate and water abstraction practices. Finally, we highlight research required to improve knowledge of the impacts of anthropogenically induced changes on lake water level and consequent changes in salinity.
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The lateral transport of bicarbonate as dissolved inorganic carbon (DIC) to the oceans is an integral component of the global carbon budget and can represent the sequestration of CO2 from the atmosphere. Recently studies have implicated land use change, in particular agricultural development, as an accelerator of bicarbonate export. However, due to the co-variation of land use, bedrock and surficial geologies, and the relationship between bicarbonate export and climate, the impact of anthropogenic activities on DIC export remains an important research question. In order to examine the land use controls on DIC export from small temperate watershedswe sampled 19 streams draining catchments of varying land uses with similar bedrock and surficial geologies. In addition to an agricultural effect, therewas a strong correlation between the percent ofwatershed in urban development and DIC concentrations and DIC yields. Urban watersheds exported 7.8 times more DIC than their nearby forested counterparts and 2.0 times more DIC than nearby agricultural catchments. Isotopic data suggest that excess DIC export from altered systems results from increased chemical weathering, enhanced CO2 production within urban green spaces, and as a result of organic matter loading from septic systems and leaky sewer lines. Furthermore, we found that nitrogen additions (e.g. fertilizers and manure) are aiding in the dissolution of lime, increasing the total export of DIC from agricultural watersheds. Calculated anthropogenic loading rates ranged from 0.43 to 0.86 mol C m−2 yr−1. These loading rates suggest that a significant portion of global DIC export might be attributable to human activities, although the impacts on CO2 sequestration are difficult to determine.