Long-term influence of climate and experimental eutrophication regimes on phytoplankton blooms

AbstractPhytoplankton blooms respond to multiple drivers, including climate change and nutrient loading. Here we examine a long-term dataset from Lake 227, a site exposed to a fertilization experiment (1969–present). Changes in nitrogen:phosphorus loading ratios (high N:P, low N:P, P-only) did not impact mean annual biomass, but blooms exhibited substantial inter- and intra-annual variability. We used a process-oriented lake model, MyLake, to successfully reproduce lake physics over 48 years and test if a P-limited model structure predicted blooms. The timing and magnitude of blooms was reproduced during the P-only period but not for the high and low N:P periods, perhaps due to N acquisition pathways not currently included in the model. A model scenario with no experimental fertilization confirmed P loading is the major driver of blooms, while a scenario that removed climate-driven temperature trends showed that increased spring temperatures have exacerbated blooms beyond the effects of fertilization alone.Significance StatementHarmful algal blooms and eutrophication are key water quality issues worldwide. Managing algal blooms is often difficult because multiple drivers, such as climate change and nutrient loading, act concurrently and potentially synergistically. Long-term datasets and simulation models allow us to parse the effects of interacting drivers of blooms. The performance of our model depended on the ratio of nitrogen to phosphorus inputs, suggesting that complex biological dynamics control blooms under variable nutrient loads. We found that blooms were dampened under a “no climate change” scenario, suggesting that the interaction of nutrient loading and increased temperature intensifies blooms. Our results highlight successes and gaps in our ability to model blooms, helping to establish future management recommendations.Data Availability StatementData and metadata will be made available in a GitHub repository (https://github.com/biogeochemistry/Lake-227). Upon manuscript acceptance, the repository will be made publicly available and a DOI will be provided. We request that data users contact the Experimental Lakes Area directly, per their data use policy (http://www.iisd.org/ela/wp-content/uploads/2016/04/Data-Terms-And-Conditions.pdf).

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Shared socioeconomic pathways for climate change research in Finland: co-developing extended SSP narratives for agriculture

Regional Environmental Change ◽

10.1007/s10113-020-01734-2 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Heikki S. Lehtonen ◽

Jyrki Aakkula ◽

Stefan Fronzek ◽

Janne Helin ◽

Mikael Hildén ◽

...

Keyword(s):

Climate Change ◽

National Level ◽

Global Scale ◽

Change Scenario ◽

Policy Makers ◽

Climate Change Research ◽

Food And Agriculture ◽

Agriculture And Food ◽

Farm Subsidies

AbstractShared socioeconomic pathways (SSPs), developed at global scale, comprise narrative descriptions and quantifications of future world developments that are intended for climate change scenario analysis. However, their extension to national and regional scales can be challenging. Here, we present SSP narratives co-developed with stakeholders for the agriculture and food sector in Finland. These are derived from intensive discussions at a workshop attended by approximately 39 participants offering a range of sectoral perspectives. Using general background descriptions of the SSPs for Europe, facilitated discussions were held in parallel for each of four SSPs reflecting very different contexts for the development of the sector up to 2050 and beyond. Discussions focused on five themes from the perspectives of consumers, producers and policy-makers, included a joint final session and allowed for post-workshop feedback. Results reflect careful sector-based, national-level interpretations of the global SSPs from which we have constructed consensus narratives. Our results also show important critical remarks and minority viewpoints. Interesting features of the Finnish narratives compared to the global SSP narratives include greater emphasis on environmental quality; significant land abandonment in SSPs with reduced livestock production and increased plant-based diets; continued need for some farm subsidies across all SSPs and opportunities for diversifying domestic production under scenarios of restricted trade. Our results can contribute to the development of more detailed national long-term scenarios for food and agriculture that are both relevant for local stakeholders and researchers as well as being consistent with global scenarios being applied internationally.

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Projecting marine fish production and catch potential in Bangladesh in the 21st century under long-term environmental change and management scenarios

ICES Journal of Marine Science ◽

10.1093/icesjms/fsv217 ◽

2015 ◽

Vol 73 (5) ◽

pp. 1357-1369 ◽

Cited By ~ 30

Author(s):

Jose A. Fernandes ◽

Susan Kay ◽

Mostafa A. R. Hossain ◽

Munir Ahmed ◽

William W. L. Cheung ◽

...

Keyword(s):

Climate Change ◽

21St Century ◽

Low Income ◽

Nutrient Loading ◽

Global Climate Model ◽

Productive Capacity ◽

Fish Production ◽

Management Scenarios ◽

Bombay Duck

Abstract The fisheries sector is crucial to the Bangladeshi economy and wellbeing, accounting for 4.4% of national gross domestic product and 22.8% of agriculture sector production, and supplying ca. 60% of the national animal protein intake. Fish is vital to the 16 million Bangladeshis living near the coast, a number that has doubled since the 1980s. Here, we develop and apply tools to project the long-term productive capacity of Bangladesh marine fisheries under climate and fisheries management scenarios, based on downscaling a global climate model, using associated river flow and nutrient loading estimates, projecting high-resolution changes in physical and biochemical ocean properties, and eventually projecting fish production and catch potential under different fishing mortality targets. We place particular interest on Hilsa shad (Tenualosa ilisha), which accounts for ca. 11% of total catches, and Bombay duck (Harpadon nehereus), a low price fish that is the second highest catch in Bangladesh and is highly consumed by low-income communities. It is concluded that the impacts of climate change, under greenhouse emissions scenario A1B, are likely to reduce the potential fish production in the Bangladesh exclusive economic zone by <10%. However, these impacts are larger for the two target species. Under sustainable management practices, we expect Hilsa shad catches to show a minor decline in potential catch by 2030 but a significant (25%) decline by 2060. However, if overexploitation is allowed, catches are projected to fall much further, by almost 95% by 2060, compared with the Business as Usual scenario for the start of the 21st century. For Bombay duck, potential catches by 2060 under sustainable scenarios will produce a decline of <20% compared with current catches. The results demonstrate that management can mitigate or exacerbate the effects of climate change on ecosystem productivity.

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Climate change impacts the protective effect of forests: A case study in Switzerland

10.21203/rs.3.rs-346221/v1 ◽

2021 ◽

Author(s):

Christine Moos ◽

Antoine Guisan ◽

Christophe F. Randin ◽

Heike Lischke

Keyword(s):

Climate Change ◽

Protective Effect ◽

Climate Warming ◽

Swiss Alps ◽

Present Species ◽

Future Research ◽

Change Scenario ◽

Climate Change Scenarios ◽

Ground Truth Data

Abstract In steep terrain, forests play an important role as natural means of protection against natural hazards, such as rockfall. Due to climate warming, significant changes in the protection service of these forests have to be expected in future. Shifts of current to more drought adapted species may result in temporary or even irreversible losses in the risk reduction provided by these forests. In this study, we assessed how the protective effect against rockfall of a protection forest in the western part of the Valais in the Swiss Alps may change in future, by combining dynamic forest modelling with a quantitative risk analysis. Current and future forest development was modelled with the spatially explicit forest model TreeMig for a moderate (RCP4.5) and an extreme (RCP8.5) climate change scenario. The simulated forest scenarios were compared to ground-truth data from the current forest complex. We quantified the protective effect of the different forest scenarios based on the reduction of rockfall risk for people and infrastructure at the bottom of the slope. Rockfall risk was calculated on the basis of three-dimensional rockfall simulations. The forest simulations predicted a clear decrease in basal area of most of the currently present species in future. The forest turned into a Q. pubescens dominated forest, for both climate scenarios, and mixed with P. sylvestris in RCP4.5. F. sylvatica completely disappeared in RCP8.5. With climate warming, a clear increase in risk is expected for both climate change scenarios. In the long-term (> 100 years), a stabilization of risk, or even a slight decline may be expected due to an increase in biomass of the trees. The results of this study further indicate that regular forest interventions may promote regeneration and thus accelerate the shift in species distribution. Future research should address the long-term effect of different forest management strategies on the protection service of forests under climate change.

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Multiple Dating of a Freeze Core from Lake 227, an Experimentally Fertilized Lake with Varved Sediments

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-231 ◽

1994 ◽

Vol 51 (10) ◽

pp. 2274-2285 ◽

Cited By ~ 13

Author(s):

Brent Wolfe ◽

Hedy J. Kling ◽

Gregg J. Brunskill ◽

Paul Wilkinson

Keyword(s):

Algal Blooms ◽

Seasonal Abundance ◽

Sedimentation Rates ◽

Experimental Lakes Area ◽

Varved Sediments ◽

Varve Chronology ◽

Freeze Core ◽

N Loading ◽

Planktonic Community

A freeze core taken from Experimental Lakes Area Lake 227 in 1988 contained 321 rhythmically paired, dark and light laminations in the upper 60.7 cm. Tape peels revealed cyclic, seasonal abundance peaks in organic and inorganic remains, which suggested that the couplets are varves. However, comparison between varve chronology and 22 yr of experimental changes in phosphorus (P) and nitrogen (N) loading and their influence on the planktonic community confirmed that the most recent varve-year estimates were 5 or 6 yr too old; this was caused by irregular sedimentation and multiple algal blooms resulting from experimental fertilization since 1969, and indistinct laminations that hampered precise couplet identification and separation. Dated horizons determined from biostratigraphic markers were used to generate compatible profiles between 1-cm slices of Lake 227 137Cs flux and reference fallout records. Nutrient concentration profiles were less helpful, as increases in carbon, N, and, P were gradual and no distinct horizon was identified as a clear marker of eutrophication. Long-term assessment of the varve chronology using 210Pb was hindered by experimental additions of 226Ra to the lake in 1970, although similar sedimentation rates from varve years 1860–1934 suggested that the varve and the deep part of the 210Pb chronologies were comparable.

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Long-Term (2001–2020) Nutrient Transport from a Small Boreal Agricultural Watershed: Hydrological Control and Potential of Retention Ponds

Water ◽

10.3390/w12102731 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2731

Author(s):

Sari Uusheimo ◽

Tiina Tulonen ◽

Jussi Huotari ◽

Lauri Arvola

Keyword(s):

Climate Change ◽

Total Nitrogen ◽

Total Phosphorus ◽

Nutrient Loading ◽

Nitrogen Loading ◽

Agricultural Watershed ◽

Weather Data ◽

Pond System ◽

Daily Weather Data

Agriculture contributes significantly to phosphorus and nitrogen loading in southern Finland. Climate change with higher winter air temperatures and precipitation may also promote loading increase further. We analyzed long-term nutrient trends (2001–2020) based on year-round weekly water sampling and daily weather data from a boreal small agricultural watershed. In addition, nutrient retention was studied in a constructed sedimentation pond system for two years. We did not find any statistically significant trends in weather conditions (temperature, precipitation, discharge, snow depth) except for an increase in discharge in March. Increasing trends in annual concentrations were found for nitrate, phosphate, and total phosphorus and total nitrogen. In fact, phosphate concentration increased in every season and nitrate concentration in other seasons except in autumn. Total phosphorus and total nitrogen concentrations increased in winter as well and total phosphorus also in summer. Increasing annual loading trend was found for total phosphorus, phosphate, and nitrate. Increasing winter loading was found for nitrate and total nitrogen, but phosphate loading increased in winter, spring, and summer. In the pond system, annual retention of total nitrogen was 1.9–4.8% and that of phosphorus 4.3–6.9%. In addition, 25–40% of suspended solids was sedimented in the ponds. Our results suggest that even small ponds can be utilized to decrease nutrient and material transport, but their retention efficiency varies between years. We conclude that nutrient loading from small boreal agricultural catchments, especially in wintertime, has already increased and is likely to increase even further in the future due to climate change. Thus, the need for new management tools to reduce loading from boreal agricultural lands becomes even more acute.

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Habitat suitability for primate conservation in north-east Brazil

Oryx ◽

10.1017/s0030605319001388 ◽

2020 ◽

Vol 54 (6) ◽

pp. 803-813

Author(s):

Bárbara Moraes ◽

Orly Razgour ◽

João Pedro Souza-Alves ◽

Jean P. Boubli ◽

Bruna Bezerra

Keyword(s):

Climate Change ◽

Protected Areas ◽

Forest Restoration ◽

Forest Cover ◽

Change Scenario ◽

Distribution Models ◽

Term Survival ◽

Priority Areas ◽

North East

AbstractBrazil has a high diversity of primates, but increasing anthropogenic pressures and climate change could influence forest cover in the country and cause future changes in the distribution of primate populations. Here we aim to assess the long-term suitability of habitats for the conservation of three threatened Brazilian primates (Alouatta belzebul, Sapajus flavius and Sapajus libidinosus) through (1) estimating their current and future distributions using species distribution models, (2) evaluating how much of the areas projected to be suitable is represented within protected areas and priority areas for biodiversity conservation, and (3) assessing the extent of remaining forest cover in areas predicted to be suitable for these species. We found that 88% of the suitable areas are outside protected areas and only 24% are located in areas with forest cover. Although not within protected areas, 27% of the climatically suitable areas are considered priority areas for conservation. Future projections, considering a severe climate change scenario, indicate that A. belzebul, S. flavius and S. libidinosus may lose up to 94, 98 and 54% of their suitable range, respectively. The establishment of primate populations and their long-term survival in these areas are at risk. Mitigation actions such as the implementation of new protected areas, forest restoration and reduction of greenhouse gas emissions will be essential for the conservation of Brazilian primates.

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Outsized nutrient contributions from small tributaries to a Great Lake

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2001376117 ◽

2020 ◽

Vol 117 (45) ◽

pp. 28175-28182

Author(s):

Robert J. Mooney ◽

Emily H. Stanley ◽

William C. Rosenthal ◽

Peter C. Esselman ◽

Anthony D. Kendall ◽

...

Keyword(s):

Algal Blooms ◽

Lake Michigan ◽

Nutrient Loading ◽

The United States ◽

Ecological Impacts ◽

Water Bodies ◽

Nutrient Loads ◽

Nutrient Inputs ◽

Small Streams ◽

Large Water

Excessive nitrogen (N) and phosphorus (P) loading is one of the greatest threats to aquatic ecosystems in the Anthropocene, causing eutrophication of rivers, lakes, and marine coastlines worldwide. For lakes across the United States, eutrophication is driven largely by nonpoint nutrient sources from tributaries that drain surrounding watersheds. Decades of monitoring and regulatory efforts have paid little attention to small tributaries of large water bodies, despite their ubiquity and potential local importance. We used a snapshot of nutrient inputs from nearly all tributaries of Lake Michigan—the world’s fifth largest freshwater lake by volume—to determine how land cover and dams alter nutrient inputs across watershed sizes. Loads, concentrations, stoichiometry (N:P), and bioavailability (percentage dissolved inorganic nutrients) varied by orders of magnitude among tributaries, creating a mosaic of coastal nutrient inputs. The 6 largest of 235 tributaries accounted for ∼70% of the daily N and P delivered to Lake Michigan. However, small tributaries exhibited nutrient loads that were high for their size and biased toward dissolved inorganic forms. Higher bioavailability of nutrients from small watersheds suggests greater potential to fuel algal blooms in coastal areas, especially given the likelihood that their plumes become trapped and then overlap in the nearshore zone. Our findings reveal an underappreciated role that small streams may play in driving coastal eutrophication in large water bodies. Although they represent only a modest proportion of lake-wide loads, expanding nutrient management efforts to address smaller watersheds could reduce the ecological impacts of nutrient loading on valuable nearshore ecosystems.

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The German Gestational Diabetes Study (PREG): Rationale, Methodology and Design

10.1101/2021.10.10.21264499 ◽

2021 ◽

Author(s):

Louise Fritsche ◽

Julia Hummel ◽

Robert Wagner ◽

Dorina Löffler ◽

Julia Hartkopf ◽

...

Keyword(s):

Gestational Diabetes ◽

Medical School ◽

Data Access ◽

Ethics Committee ◽

Data Availability ◽

List Type ◽

Diabetes Research ◽

Link Type ◽

Study Participants

AbstractIntroductionSince the introduction of the new International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria for gestational diabetes mellitus (GDM) in 2012, diagnosis and treatment of GDM has improved. But even well-treated GDM might still have impact on long-term health of the mother and her offspring, though, this relation has not been conclusively studied yet.MethodsThe multicenter PREG study is designed to metabolically and phenotypically characterize women with a 75 g five-point oral glucose tolerance test (OGTT) during and repeatedly after pregnancy. The offspring of the study participants are followed up until adulthood with developmental tests and metabolic and epigenetic phenotyping in the PREG offspring study. By in-depth phenotyping of the mother and her offspring, we aim to elucidate the relationship of maternal hyperglycemia during pregnancy and adequate treatment and its impact on the long-term health for both.Ethics and disseminationThe study protocol has been reviewed and approved by the ethics committee of the University Hospital Tübingen (protocol numbers 218/2012BO2 and 617/2020BO1), the ethics committee of the Technical University Dresden (protocol number EK263072013), the ethics committee of the medical school of the Heinrich Heine University Düsseldorf (protocol number 4051) and the ethics committee of the medical school of University of Leipzig (protocol number 038-15-09032015). The results will be disseminated through conference presentations and peer-reviewed publications.RegistrationThe PREG study and the PREG offspring study are registered with Clinical Trials (ClinicalTrials.gov Identifiers: NCT04270578, NCT04722900).Strengths and limitations of this studyThe main strength of the multicenter PREG study are the in-depth phenotyping of mothers during pregnancy and repeatedly after delivery.Data acquisition and sample handling are done according to standard operating procedures in all study sites, thus, ensuring a high quality for each data point.A PREG biobank is set up and samples are available for researchers of the German Center for Diabetes Research (DZD).Children of the study participants are repeatedly examined to cover the period of childhood and adolescence.The PREG study is not planned as a population-based cohort but is enriched for GDM cases.Data Availability StatementAll requests for data and materials will be promptly reviewed by the Data Access Steering Committee to verify whether the request is subject to any intellectual property or confidentiality obligations. Individual-level data may be subject to confidentiality. Any data and materials that can be shared will be released via a Material Transfer Agreement.

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HSPF-Based Assessment of Inland Nutrient Source Control Strategies to Reduce Algal Blooms in Streams in Response to Future Climate Changes

Sustainability ◽

10.3390/su132212413 ◽

2021 ◽

Vol 13 (22) ◽

pp. 12413

Author(s):

Dong Hoon Lee ◽

Pamela Sofia Fabian ◽

Jin Hwi Kim ◽

Joo-Hyon Kang

Keyword(s):

Climate Change ◽

Algal Blooms ◽

Agricultural Land ◽

Wastewater Treatment Plants ◽

Control Strategies ◽

Source Control ◽

Change Scenario ◽

Climate Change Scenarios ◽

Source Reduction ◽

Chl A

The HSPF model was modified to improve the growth-temperature formulation of phytoplankton and used to simulate Chl-a concentrations at the outlet of the Seom River watershed in Korea from 2025 to 2050 under four climate change scenarios: RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5. The mean and median Chl-a concentrations increased by 5–10% and 23–29%, respectively, and the number of algal outbreak cases per year (defined as a day with Chl-a concentration ≥100 µg/L) decreased by 31–88% relative to the current values (2011–2015). Among the climate change scenarios, RCP 2.6 (stringent) showed the largest number of algal outbreak cases, mainly because of the largest yearly variability of precipitation and TP load. For each climate change scenario, three nutrient load reduction scenarios were in the HSPF simulation, and their efficiencies in reducing algal blooms were determined. Nonpoint source reduction in TP and TN from urban land, agricultural land, and grassland by 50% (S1) and controlling the effluent TP concentration of wastewater treatment plants (WWTPs) to 0.1 mg/L (S2) decreased algal outbreaks by 20–58% and 44–100%, respectively. The combination of effluent TP control of WWTPs during summer and S1 was the most effective management scenario; it could almost completely prevent algal outbreaks. This study demonstrates the cost effectiveness of using a season-based pollutant management strategy for controlling algal blooms.

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Ozone Effects on Douro Vineyards under Climate Change

Atmosphere ◽

10.3390/atmos12101238 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1238

Author(s):

Ana Ascenso ◽

Carla Gama ◽

Carlos Silveira ◽

Carolina Viceto ◽

Alfredo Rocha ◽

...

Keyword(s):

Climate Change ◽

Transport Model ◽

Meteorological Data ◽

Sugar Content ◽

Air Pollutant ◽

Pollutant Emissions ◽

Change Scenario ◽

Response Functions ◽

Chemical Transport Model

Tropospheric ozone (O3) levels in southern Europe have an increasing tendency, in close relation with the higher incidence of hot summers and heatwaves. Given that O3 is one of the most damaging pollutants for vegetation, known to affect productivity and quality of crops, it is necessary to develop more rigorous and consistent methods of risk assessment that consider climate change conditions. Studying the O3 deposition over the Douro Demarcated Region (DDR), which is one of the most productive wine areas in Portugal, and assessing its potential effects under a climate change scenario, was the purpose of this study. To that end, the chemical transport model CHIMERE, with a spatial resolution of 1 km2, fed by meteorological data from the WRF model, was applied for a recent past climate (2003 to 2005) and future mid-term (2049 and 2064) and long-term (2096 and 2097) scenarios. Simulations for future climate were performed considering: (i) only the climate change effect, and (ii) the effect of climate change together with future air pollutant emissions. The assessment of the potential damage in terms of wine productivity and quality (sugar content) was performed through analysis of O3 deposition and the application of concentration–response functions, based on AOT40 values. Modeling results show that a reduction in emission of O3 precursors can successfully decrease AOT40 levels in the DDR, but it is not enough to accomplish the European Commission target value for the protection of vegetation. If the emissions remain constant, the exposure–response functions indicate that, in the long-term, AOT40 levels could worsen wine productivity and quality.

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