Water supplies a wealth of value to both humans and nature. Finding the limits to pollution to our waters is essential to maintain ecosystem services. Through co-creation we find effective and novel solutions to ensure future water quality.


Sven Teurlincx is an aquatic ecologist with a strong interest in stakeholder involvement. Sven has worked on many projects where he tries to balance the desire of human use of water bodies with ecological quality of water systems in terms of biodiversity, ecosystem functioning and ecosystem services.



  • 2019–Present
    Project manager @NIOO-KNAW
  • 2016–2019
    Postdoc @NIOO-KNAW
  • 2012–2016
    PhD researcher @NIOO-KNAW


  • 2012–2019
    PhD research: Connecting the ditches: a spatial perspective on biodiversity in Dutch polder landscapes
  • 2009–2012
    Master's Environmental Biology @Utrecht University
  • 2006–2009
    Bachelor's Biology @ Utrecht University

PhD students

  • 2019–Present
    Lilith Kramer
    NIOO-KNAW, Wageningen University
    Promotors en Copromotors: Tineke Troost, Wolf Mooij
  • 2016–2020
    Manqi Chang
    NIOO-KNAW, Wageningen University
    Promotors en Copromotors: Wolf Mooij, Annette Janssen



Peer-reviewed publicaties

  • Environmental Pollution

    Effect of an antidepressant on aquatic ecosystems in the presence of microplastics

    Nandini Raman, Berte Mekonen Belay, Josie South, Tarryn L. Botha, Josephine Pegg, Dumisani Khosa, Lubabalo Mofu, Gina Walsh, Martine S. Jordaan, Albert A Koelmans, Sven Teurlincx, Nico Helmsing, Nina de Jong, Ellen Van Donk, Miquel Lürling, Victor Wepener, Tania Vasconcelos Fernandes, Lisette de Senerpont Domis
    Emerging pollutants, such as pharmaceuticals and microplastics have become a pressing concern due to their widespread presence and potential impacts on ecological systems. To assess the ecosystem-level effects of these pollutants within a multi-stressor context, we simulated real-world conditions by exposing a near-natural multi-trophic aquatic food web to a gradient of environmentally relevant concentrations of fluoxetine and microplastics in large mesocosms over a period of more than three months. We measured the biomass and abundance of different trophic groups, as well as ecological functions such as nutrient availability and decomposition rate. To explore the mechanisms underlying potential community and ecosystem-level effects, we also performed behavioral assays focusing on locomotion parameters as a response variable in three species: Daphnia magna (zooplankton prey), Chaoborus flavicans larvae (invertebrate pelagic predator of zooplankton) and Asellus aquaticus (benthic macroinvertebrate), using water from the mesocosms. Our mesocosm results demonstrate that presence of microplastics governs the response in phytoplankton biomass, with a weak non-monotonic dose-response relationship due to the interaction between microplastics and fluoxetine. However, exposure to fluoxetine evoked a strong non-monotonic dose-response in zooplankton abundance and microbial decomposition rate of plant material. In the behavioral assays, the locomotion of zooplankton prey D. magna showed a similar non-monotonic response primarily induced by fluoxetine. Its predator C. flavicans, however, showed a significant non-monotonic response governed by both microplastics and fluoxetine. The behavior of the decomposer A. aquaticus significantly decreased at higher fluoxetine concentrations, potentially leading to reduced decomposition rates near the sediment. Our study demonstrates that effects observed upon short-term exposure result in more pronounced ecosystem-level effects following chronic exposure.
  • Lake and Reservoir Management

    A lake management framework for global application: monitoring, restoring, and protecting lakes through community engagement

    Jacob A. Cianci-Gaskill, Jennifer L. Klug, Kellie C. Merrell, Edward Millar, Danielle J. Wain, Lilith Kramer, Dianneke van Wijk, Ma Cristina A. Paule-Mercado, Kerri Finlay, Max R. Glines, Elias Munthali, Sven Teurlincx, Lisa Borre, Norman D. Yan
    Despite decades of management and regulation, global freshwater resources remain imperiled. Management has had mixed success in restoring degraded lakes and has few mechanisms for stopping the decline of high-quality systems. Too often, lake managers play catch-up by addressing stressors only after damage occurs or has become entrenched, or make decisions without acquiring sufficient information about how a lake might respond to proposed management actions. As a tool to address these management challenges, we propose the MoReCo (Monitoring, Restoring/Protecting, Community Engagement) lake management framework. The framework centers around community engagement, and we outline engagement mechanisms in the context of lake management. The framework includes 2 loops: a monitoring loop to detect emerging stressors, and a restoring/protecting loop to address stressors that are causing or may cause lake degradation. The MoReCo framework builds on the strengths of existing natural resource management frameworks and was developed to address the unique challenges associated with lake management and protection, as well as those resulting from climate change. Specifically, it can address multiple stressors concurrently, which makes it simultaneously suitable for ameliorating stressors while also protecting lake ecosystems. The MoReCo framework is an interactive and multidirectional process in which management occurs even when no stressor is apparent, and it incorporates explicit benchmarks for evaluating management actions and determining whether additional measures should be taken. This novel lake management framework is suitable to address any stressors that may threaten a lake ecosystem, and we present it here as a resource for those who manage freshwater resources.
  • Philosophical transactions of the Royal Society of London. Series B, Biological sciences

    Long-term exposure to experimental light affects the ground-dwelling invertebrate community, independent of light spectra

    Kamiel Spoelstra, Sven Teurlincx, Matthijs Courbois, Zoë M. Hopkins, Marcel E. Visser, Therésa M. Jones, Gareth R. Hopkins

    Our planet endures a progressive increase in artificial light at night (ALAN), which affects virtually all species, and thereby biodiversity. Mitigation strategies include reducing its intensity and duration, and the adjustment of light spectrum using modern light emitting diode (LED) light sources. Here, we studied ground-dwelling invertebrate (predominantly insects, arachnids, molluscs, millipedes, woodlice and worms) diversity and community composition after 3 or 4 years of continued nightly exposure (every night from sunset to sunrise) to experimental ALAN with three different spectra (white-, and green- and red-dominated light), as well as for a dark control, in natural forest-edge habitat. Diversity of pitfall-trapped ground-dwelling invertebrates, and the local contribution to beta diversity, did not differ between the dark control and illuminated sites, or between the different spectra. The invertebrate community composition, however, was significantly affected by the presence of light. Keeping lights off during single nights did show an immediate effect on the composition of trapped invertebrates compared to illuminated nights. These effects of light on species composition may impact ecosystems by cascading effects across the food web. This article is part of the theme issue 'Light pollution in complex ecological systems'.
  • Journal of Environmental Management

    Process-based modeling for ecosystem service provisioning

    Qing Zhan, Lisette de Senerpont Domis, Miquel Lürling, Rafael Marcé, Tom S. Heuts, Sven Teurlincx

    Healthy freshwater ecosystems can provide vital ecosystem services (ESs), and this capacity may be hampered due to water quality deterioration and climate change. In the currently available ES modeling tools, ecosystem processes are either absent or oversimplified, hindering the evaluation of impacts of restoration measures on ES provisioning. In this study, we propose an ES modeling tool that integrates lake physics, ecology and service provisioning into a holistic modeling framework. We applied this model to a Dutch quarry lake, to evaluate how nine ESs respond to technological-based (phosphorus (P) reduction) and nature-based measures (wetland restoration). As climate change might be affecting the future effectiveness of restoration efforts, we also studied the climate change impacts on the outcome of restoration measures and provisioning of ESs, using climate scenarios for the Netherlands in 2050. Our results indicate that both phosphorus reduction and wetland restoration mitigated eutrophication symptoms, resulting in increased oxygen concentrations and water transparency, and decreased phytoplankton biomass. Delivery of most ESs was improved, including swimming, P retention, and macrophyte habitat, whereas the ES provisioning that required a more productive system was impaired (sport fishing and bird watching). However, our modeling results suggested hampered effectiveness of restoration measures upon exposure to future climate conditions, which may require intensification of restoration efforts in the future to meet restoration targets. Importantly, ESs provisioning showed non-linear responses to increasing intensity of restoration measures, indicating that effectiveness of restoration measures does not necessarily increase proportionally. In conclusion, the ecosystem service modeling framework proposed in this study, provides a holistic evaluation of lake restoration measures on ecosystem services provisioning, and can contribute to development of climate-robust management strategies.
  • Ecological Indicators

    Timing matters

    Alena Gsell, Sven Teurlincx, Rita Adrian, Annette B.G. Janssen
    Shallow lakes are known for sudden shifts between a desired clear and an undesired turbid state despite only incremental changes in the underlying drivers. Such sudden shifts are a major challenge for lake managers who can be confronted with abrupt losses of desired ecosystem services without easily observable warning signals. Predictive tools for the loss of ecosystem resilience are vital to respond with timely mitigation measures and avert a shift to the undesired state. Early-warning indicators (EWIs) have faithfully preceded critical transitions in minimal models but have proven more elusive in real-world data, suggesting a mismatch between measurement strategy and the detectability of EWIs. Here, we capitalize on data simulated using the aquatic ecosystem model PCLake+ which represents real systems more closely than reductionistic models and which allows the generation of critical transitions in response to gradual changes in phosphorus load. We tested the effect of different sampling intervals (daily to yearly) on the detection of three often-used EWIs across a range of food web and nutrient-related variables. Moreover, we included one integrated sampling interval (yearly average of daily measurements) to represent time-integrated measurements. EWIs generally performed better at shorter intervals (daily, weekly) but integrated measurements over the year also proved suitable to detect oncoming state shifts. We propose that lake managers should aim for high-frequency measurements of variables that can be easily and cheaply measured (e.g. oxygen, Secchi) or, alternatively, focus on integrated approaches using passive samplers or sedimented material.
  • Environmental Modelling and Software

    Connecting lakes: Modeling flows and interactions of organisms and matter throughout the waterscape

    Lilith Kramer, Tineke A. Troost, Annette B.G. Janssen, Bob Brederveld, Luuk P.A. Van Gerven, Dianneke van Wijk, Wolf M. Mooij, Sven Teurlincx
    Eutrophication poses a threat to lake ecosystem services provisioning worldwide. When eutrophic lakes are connected to other water systems, either through water flows, or through organismal movement and dispersal, their excess nutrients affect nearby lakes too. Understanding nutrient transport dynamics in lake meta-ecosystems is not trivial, as it encompasses the complexity of ecosystems themselves (i.e., food web dynamics, nutrient cycling) and the transport between ecosystems. Hitherto, it remains unknown how heterogeneity in lake meta-ecosystems affects their ecological resilience. We argue that scientists and water managers would benefit from the use of meta-ecosystem models while unravelling meta-ecosystem complexity. To this end, we converted lake ecosystem model PCLake+ into lake meta-ecosystem model PCLakeS+. We showed that the spatial configuration of a lake meta-ecosystem influences its ecological dynamics, and that nutrient transport depends heavily on food web processes. We conclude that PCLakeS+ is suitable for exploring meta-ecosystem concepts for science and water management.
  • Water Research

    Regime shifts in shallow lakes explained by critical turbidity

    Dianneke van Wijk, Manqi Chang, Annette B.G. Janssen, Sven Teurlincx, Wolf M. Mooij

    Worldwide, water quality managers target a clear, macrophyte-dominated state over a turbid, phytoplankton-dominated state in shallow lakes. The competition mechanisms underlying these ecological states were explored in the 1990s, but the concept of critical turbidity seems neglected in contemporary water quality models. In particular, a simple mechanistic model of alternative stable states in shallow lakes accounting for resource competition mechanisms and critical turbidity is lacking. To this end, we combined Scheffer's theory on critical turbidity with insights from nutrient and light competition theory founded by Tilman, Huisman and Weissing. This resulted in a novel graphical and mathematical model, GPLake-M, that is relatively simple and mechanistically understandable and yet captures the essential mechanisms leading to alternative stable states in shallow lakes. The process-based PCLake model was used to parameterize the model parameters and to test GPLake-M using a pattern-oriented strategy. GPLake-M's application range and position in the model spectrum are discussed. We believe that our results support the fundamental understanding of regime shifts in shallow lakes and provide a starting point for further mechanistic and management-focused explorations and model development. Furthermore, the concept of critical turbidity and the relation between light-limited submerged macrophytes and nutrient-limited phytoplankton might provide a new focus for empirical aquatic ecological research and water quality monitoring programs.
  • Sustainability Science

    New paths for modelling freshwater nature futures

    Lilith Kramer, Sven Teurlincx, Brenda Rashleigh, Annette B.G. Janssen, Jan H. Janse, Kate A. Brauman, Csaba Földesi, Dianneke van Wijk, Lisette de Senerpont Domis, Sopan D. Patil, Parinaz Rashidi, Perrine Hamel, James Rising, Wolf M. Mooij, Jan J. Kuiper
    Freshwater ecosystems are exceptionally rich in biodiversity and provide essential benefits to people. Yet they are disproportionately threatened compared to terrestrial and marine systems and remain underrepresented in the scenarios and models used for global environmental assessments. The Nature Futures Framework (NFF) has recently been proposed to advance the contribution of scenarios and models for environmental assessments. This framework places the diverse relationships between people and nature at its core, identifying three value perspectives as points of departure: Nature for Nature, Nature for Society, and Nature as Culture. We explore how the NFF may be implemented for improved assessment of freshwater ecosystems. First, we outline how the NFF and its main value perspectives can be translated to freshwater systems and explore what desirable freshwater futures would look like from each of the above perspectives. Second, we review scenario strategies and current models to examine how freshwater modelling can be linked to the NFF in terms of its aims and outcomes. In doing so, we also identify which aspects of the NFF framework are not yet captured in current freshwater models and suggest possible ways to bridge them. Our analysis provides future directions for a more holistic freshwater model and scenario development and demonstrates how society can benefit from freshwater modelling efforts that are integrated with the value-perspectives of the NFF.
  • Freshwater Biology

    Stressors in a bottle

    Maggie Armstrong, Qing Zhan, Elias Munthali, Hui Jin, Sven Teurlincx, Piet Peters, Miquel Lürling, Lisette de Senerpont Domis
    The climatic stressors that are affecting lake ecosystems, especially phytoplankton, are projected to become more intense with continued climate change (e.g., heatwaves, precipitation events). Concerns over the combined effects that multiple, coinciding stressors can have on phytoplankton necessitates investigating the impacts of different regional climate scenarios.
    A microcosm study was conducted to assess the responses of a phytoplankton assemblage containing a cyanobacterium (Anabaena flos-aquae), a green alga (Chlorella vulgaris) and a diatom (Synedra) to a northwestern European summer scenario. Eutrophic microcosms were exposed to a full-factorial design including a press temperature treatment scenario (ambient or warm) and a pulse precipitation treatment (no runoff simulation or runoff simulation).
    Warming scenarios had significant effects on the phytoplankton assemblage biomass, which supports our first hypothesis (H1: higher water temperatures under eutrophic conditions will support larger phytoplankton biomasses, especially cyanobacteria). By contrast, the extreme precipitation runoff event had minimal and short-lived effects on the microcosm assemblage.
    Overall, the interaction between the two climate stressors was antagonistic. In contrast with our second hypothesis (H2: nutrient additions from extreme precipitation runoff will promote more productivity in higher temperature microcosms), the precipitation runoff event was not amplified by temperature.
    Our results indicate that the combined effect of two climate stressors on a phytoplankton community are not necessarily synergistic or multiplicative. Our findings on antagonistic interactions between climatic stressors necessitate future studies assessing variations of intensity and duration of the climatic stressors.
  • Freshwater Biology

    Salinisation effects on freshwater macrophyte growth and establishment in coastal eutrophic agricultural ditches

    Mandy Velthuis, Sven Teurlincx, Gijs van Dijk, Alfons J. P. Smolders, Lisette de Senerpont Domis

    The presence of submerged macrophytes is a desired environmental target for coastal freshwater ecosystems. Maintaining a rich community of these species can be challenging as salinisation by sea-level rise poses an increasing threat to ecosystem integrity. We tested the effect of salinisation on the growth and germination of freshwater macrophytes experimentally using field sediment. In a 56-day experiment, a macrophyte community was exposed to salinity treatments representing seasonal water management scenarios (a decreasing salinity from 1,500 to 300 mg NaCl/L, a stable salinity of 300 mg NaCl/L, an increasing salinity from 300 to 1,500 mg NaCl/L and a stable salinity of 1,500 mg NaCl/L), crossed with treatments simulating periodic turbidity pulses. All species except Elodea nuttallii grew poorly on the saline and eutrophic sediment, reflecting the challenges of growth in eutrophic coastal systems. Surprisingly, the highest community biomass was achieved in the salinity scenario of 1,500 mg NaCl/L. In a second experiment, field-collected sediments were incubated at 300 and 1,500 mg NaCl/L salinity (representing summer and winter scenarios), and the germination capacity of the existing seedbank was quantified. Most germinated seedlings did not reach maturity irrespective of salinity treatment. This indicated that sediment salinity, rather than water column salinity, determined seedling establishment success. Interestingly, the established species were characteristic of freshwater habitats, thus indicating maladaptation of the seedbank. Our results show that a mismatch between the high salinity level of eutrophic sediment and the overlaying freshwater may hamper macrophyte growth. Furthermore, target species in coastal eutrophic freshwaters should be evaluated carefully. Elodea nuttalli, which has a wide tolerance range for nutrients and salinity, outperformed other macrophyte species in our study. Thus, species with similar traits may be most successful in establishing macrophyte stands in coastal eutropic wetlands.
  • Science of the Total Environment

    What is the pollution limit? Comparing nutrient loads with thresholds to improve water quality in Lake Baiyangdian

    Jing Yang, Maryna Strokal, Carolien Kroeze, Lin Ma, Zhaohai Bai, Sven Teurlincx, Annette B.G. Janssen

    Ecological thresholds are useful indicators for water quality managers to define limits to nutrient pollution. A common approach to estimating ecological thresholds is using critical nutrient loads. Critical nutrient loads are typically defined as the loads at which the phytoplankton chlorophyll-a exceeds a certain concentration. However, national policies, such as in China, use chemical indicators (nitrogen and phosphorus concentrations) rather than ecological indicators (phytoplankton chlorophyll-a) to assess water quality. In this study, we uniquely define the critical nutrient loads based on maximum allowable nutrient concentrations for lake Baiyangdian. We assess whether current and future nutrient loads in this lake comply with the Chinese Water Quality standards. To this end, we link two models (MARINA-Lakes and PCLake+). The PCLake+ model was applied to estimate the critical nutrient loads related to ecological thresholds for total nitrogen, total phosphorus and chlorophyll-a. The current (i.e., 2012) and future (i.e., 2050) nutrient loads were derived from the water quality MARINA-Lakes model. Nitrogen loads exceeded the nitrogen threshold in 2012. Phosphorus loads were below all ecological thresholds in 2012. Ecological thresholds are exceeded in 2050 with limited environmental policies, and urbanization may increase nutrient loads above the ecological thresholds in 2050. Recycling and reallocating animal manure is needed to avoid future water pollution in Lake Baiyangdian. Our study highlights the need for effective policies for clean water based on policy-relevant indicators.
  • Freshwater Biology

    Long-term trends and seasonal variation in host density, temperature, and nutrients differentially affect chytrid fungi parasitising lake phytoplankton

    Alena Gsell, Justyna Wolinska, Katrin Preuß, Sven Teurlincx, Deniz Özkundakci, Sabine Hilt, Ellen Van Donk, Bas Ibelings, Rita Adrian

    Parasites are generally considered the most commonly occurring type of consumers, yet their biomass and population dynamics are rarely quantified at community level. Here, we used 12 years of weekly or fortnightly monitoring data (518 time points) to determine the occurrence of chytrids, fungal parasites of phytoplankton, to assess their seasonality and long-term (seasonally-detrended) dynamics in the pelagic plankton community of a temperate, eutrophic, and polymictic lake. Chytrid infections were observed in c. 75% of all samples with recurrent infections in multiple host taxa. Infection prevalence was highest in spring, but infections occurred throughout the entire year with an average of 2.3 host taxa infected per time point (ranging from 0 to 10 host taxa) and an average infection prevalence of 2.78% (ranging from 0% to 47.35%). Infected host biomass equalled that of the carnivorous zooplankton and decreased over time, while infection prevalence remained unchanged. Seasonal infection prevalence increased with phytoplankton biomass, but decreased with increasing temperature and phosphorus concentrations, reflecting that peak prevalence occurred in spring when temperature and phosphorus concentrations were relatively low. In contrast, seasonally-detrended prevalence increased with temperature, but decreased with increasing phosphorus concentrations. Chytrids are a common component of the pelagic plankton community with sizeable biomass and removing an—at times—substantial proportion of the primary production, challenging the long-standing underrepresentation of parasites in ecological studies. Chytrids responded differentially to seasonal variation and long-term trends in host density, water temperature and nutrient availability, highlighting the need to disentangle seasonal signals from long-term changes.
  • Water Research

    Making waves: Lessons learned from the COVID-19 anthropause in the Netherlands on urban aquatic ecosystem services provisioning and management

    Maggie Armstrong, Hazal Aksu Bahçeci, Ellen Van Donk, Asmita Dubey, Thijs Frenken, Berte Mekonen Belay, Alena Gsell, Tom S. Heuts, Lilith Kramer, Miquel Lürling, Maarten Ouboter, Laura Seelen, Sven Teurlincx, Nandini Raman, Qing Zhan, Lisette de Senerpont Domis


    As human mobility decreased in 2020, the interaction between humans and nature changed significantly. On one hand, water clarity improved in the Amsterdam canals because boat traffic was reduced. On the other hand increased use of fishing water and national parks formed potential threats to the aquatic ecosystems. It is important to use these experiences to foster a more eco-centric mindset, building up to handling handling climate change and future pandemics.


    The anomalous past two years of the COVID-19 pandemic have been a test of human response to global crisis management as typical human activities were significantly altered. The COVID-instigated anthropause has illustrated the influence that humans and the biosphere have on each other, especially given the variety of national mobility interventions that have been implemented globally. These local COVID-19-era restrictions influenced human-ecosystem interactions through changes in accessibility of water systems and changes in ecosystem service demand. Four urban aquatic case studies in the Netherlands demonstrated shifts in human demand during the anthropause. For instance, reduced boat traffic in Amsterdam canals led to improved water clarity. In comparison, ongoing service exploitation from increased recreational fishing, use of bathing waters and national parks visitation are heightening concerns about potential ecosystem degradation. We distilled management lessons from both the case studies as well as from recent literature pertaining to ecological intactness and social relevance. Equally important to the lessons themselves, however, is the pace at which informed management practices are established after the pandemic ends, particularly as many communities currently recognize the importance of aquatic ecosystems and are amenable to their protection.
  • Inland Waters

    Smart Nutrient Retention Networks

    Dianneke van Wijk, Sven Teurlincx, Bob Brederveld, J.J.M de Klein, Annette B.G. Janssen, Lilith Kramer, Luuk P.A. Van Gerven, C. Kroeze, Wolf M. Mooij
    Nutrients are essential resources for food production but are used inefficiently, and thereby they pollute inland and coastal waters and are lost into the oceans. Nutrient conservation by retention and consecutive reuse would prevent nutrient losses to the atmosphere and downstream ecosystems. We present Smart Nutrient Retention Networks (SNRNs) as a novel management approach to achieve nutrient conservation across networks of connected waterbodies through strategic water quality management. To present the key features of SNRNs, we review existing knowledge of nutrient retention processes in inland waters, water quality management options for nutrient conservation, and nutrient retention models to develop SNRNs. We argue that successful nutrient conservation, even at a local level, through SNRN management strategies requires clearly formulated goals and catchment-wide system understanding. Waterbody characteristics, such as hydraulic residence time and the presence of macrophytes, shape local nutrient retention with potential network-wide cascading effects of improved water quality and are therefore key targets of SNRN management strategies. Nutrient retention models that include the self-reinforcing feedback loop of ecological water quality, nutrient retention, and nutrient loading in networks of inland waters in relation to management options can support the development of SNRNs. We conclude that SNRNs can contribute to sustainable use of nutrients in human food production.
  • Earth System Science Data

    The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil

    Kailiang Yu, Johan van den Hoogen, Zhikang Wang, C. Averill, D. Routh, Robert G Smith, R. E. Drenovsky, K. M. Scow, F. Mo, M. P. Waldrop, Yuanhe Yang, Wen Tang, Franciska T. De Vries, Richard D. Bardgett, P. Manning, Felipe Bastida, S. G. Baer, Elizabeth M. Bach, Carlos González-García, Qingkui Wang, L. Ma, Baodong Chen, X. He, Sven Teurlincx, Amber Heijboer, J. A. Bradley, Tom Crowther
    Fungi and bacteria are the two dominant groups of soil microbial communities worldwide. By controlling the turnover of soil organic matter, these organisms directly regulate the cycling of carbon between the soil and the atmosphere. Fundamental differences in the physiology and life history of bacteria and fungi suggest that variation in the biogeography of relative abundance of soil fungi versus bacteria could drive striking differences in carbon decomposition and soil organic matter formation between different biomes. However, a lack of global and predictive information on the distribution of these organisms in terrestrial ecosystems has prevented the inclusion of relative abundance of soil fungi versus bacteria and the associated processes in global biogeochemical models. Here, we used a global-scale dataset of >3000 distinct observations of abundance of soil fungi versus bacteria in the surface topsoil (up to 15 cm) to generate the first quantitative and high-spatial-resolution (1 km2) explicit map of soil fungal proportion, defined as fungi/fungi + bacteria, across terrestrial ecosystems. We reveal striking latitudinal trends where fungal dominance increases in cold and high-latitude environments with large soil carbon stocks. There was a strong nonlinear response of fungal dominance to the environmental gradient, i.e., mean annual temperature (MAT) and net primary productivity (NPP). Fungi dominated in regions with low MAT and NPP and bacteria dominated in regions with high MAT and NPP, thus representing slow vs. fast soil energy channels, respectively, a concept with a long history in soil ecology. These high-resolution models provide the first steps towards representing the major soil microbial groups and their functional differences in global biogeochemical models to improve predictions of soil organic matter turnover under current and future climate scenarios. Raw datasets and global maps generated in this study are available at 10.6084/m9.figshare.19556419 (Yu, 2022).
  • Landschap

    Nationaal Park 3.0

    Protected areas are the cornerstone of nature conservation, although this approach has not prevented the current biodiversity crisis. In addition, the approach leads to the suggestion that only organisms living within these areas constitute nature. Nature, however, cannot be spatially constrained, and the same holds for human influence on nature. In this essay we develop an area-wide and human-inclusive vision of nature conservation into a new approach for national parks that we call National Park 3.0 (NP 3.0). The concept is rooted in a re-evaluation of human-nature relations sensu the Nature Futures Framework developed under IPBES. Moreover, we note that ‘landscape’ has always been a social-ecological concept since the term was coined by 17th century Dutch painters. Finally, we note that nature and human infrastructure are deeply entangled at multiple spatial scales in modern landscapes. We define NP 3.0 spatially by the contours of a landscape that is recognizable by people and has geomorphological and ecological coherence. We relate NP 3.0 to other initiatives for restoring biodiversity and provide a conceptual design for NP 3.0. Throughout this essay we use Nationaal Park Hollandse Duinen as a case study where NP 3.0 is worked out in practice.
  • Ecological Modelling

    A generically parameterized model of Lake eutrophication

    Manqi Chang, Donald L. DeAngelis, Jan H. Janse, Annette B.G. Janssen, Tineke A. Troost, Dianneke van Wijk, Wolf M. Mooij, Sven Teurlincx

    Water quality improvement to avoid excessive phytoplankton blooms often requires eutrophication management where both phosphorus (P) and nitrogen (N) play a role. While empirical eutrophication studies and ecological resource competition theory both provide insight into phytoplankton abundance in response to nutrient loading, they are not seamlessly linked in the current state of eutrophication research. We argue that understanding species competition for multiple nutrients and light in natural phytoplankton communities is key to assessing phytoplankton abundance under changing nutrient supply. Here we present GPLake-S, a mechanistic model rooted in ecological resource competition theory, which has only eight parameters and can predict chlorophyll-a to nutrient relationships for phytoplankton communities under N, P, N+P colimitation and light limitation. GPLake-S offers a simple mechanistic tool to make first estimates of chlorophyll-a levels and nutrient thresholds for generic lake properties, accounting for variation in N:P ratio preferences of phytoplankton species. This makes the model supportive of water management and policy.
  • PLoS One

    Monitoring biological water quality by volunteers complements professional assessments

    Edwin T.H.M. Peeters, Anton A.M. Gerritsen, Laura Seelen, Matthijs Begheyn, Froukje Rienks, Sven Teurlincx

    Progressively more community initiatives have been undertaken over last decades to monitor water quality. Biological data collected by volunteers has been used for biodiversity and water quality studies. Despite the many citizen science projects collecting and using macroinvertebrates, the number of scientific peer-reviewed publications that use this data, remains limited. In 2018, a citizen science project on biological water quality assessment was launched in the Netherlands. In this project, volunteers collect macroinvertebrates from a nearby waterbody, identify and count the number of specimens, and register the catch through a web portal to instantaneously receive a water quality score based on their data. Water quality monitoring in the Netherlands is traditionally the field of professionals working at water authorities. Here, we compare the data from the citizen science project with the data gathered by professionals. We evaluate information regarding type and distribution of sampled waterbodies and sampling period, and compare general patterns in both datasets with respect to collected animals and calculated water quality scores. The results show that volunteers and professionals seldomly sample the same waterbody, that there is some overlap in sampling period, and that volunteers more frequently sampled urban waters and smaller waterbodies. The citizen science project is thus yielding data about understudied waters and this spatial and temporal complementarity is useful. The character and thoroughness of the assessments by volunteers and professionals are likely to differentiate. Volunteers collected significantly lower numbers of animals per sample and fewer animals from soft sediments like worms and more mobile individuals from the open water column such as boatsmen and beetles. Due to the lack of simultaneous observations at various locations by volunteers and professionals, a direct comparison of water quality scores is impossible. However, the obtained patterns from both datasets show that the water quality scores between volunteers and professionals are dissimilar for the different water types. To bridge these differences, new tools and processes need to be further developed to increase the value of monitoring biological water quality by volunteers for professionals.
  • Inland Waters

    Serving many masters at once

    Laura Seelen, Sven Teurlincx, Maggie Armstrong, Miquel Lürling, Ellen Van Donk, Lisette de Senerpont Domis

    Globally the number of relatively deep, isolated lakes is increasing because of sand, gravel, or clay excavation activities. The major excavation areas are located within the delta of rivers, and thus the deep freshwater ecosystems formed upon excavation, called quarry lakes, are unique to the landscape. They are embedded in a landscape comprised of shallow, naturally formed lakes. Given that quarry lakes are by definition novel ecosystems, water managers face difficulties in optimally managing them to deliver ecosystem services using existing frameworks designed for natural ecosystems. All lakes in delta areas are subject to similar pressures such as urbanization and eutrophication, leading to shifts in biodiversity and ecosystem functioning, and ultimately changing the ecosystem services the systems can provide. We propose a framework to enable water managers to assess the provision of ecosystem services by quarry lakes based on their ecological quality. For each ecosystem service we determined threshold values of ecological quality based on available scientific literature, an extensive field survey of 51 quarry lakes in the Netherlands, or expert knowledge. To illustrate the usefulness of our approach, we applied our framework to a lake before and after a rehabilitation focused on improving the nutrient status of the waterbody. Assessing ecosystem services under varying levels of ecological health is important to initiate action from legislators, managers, and communities.
  • Science of the Total Environment

    Towards climate-robust water quality management: Testing the efficacy of different eutrophication control measures during a heatwave in an urban canal

    Qing Zhan, Sven Teurlincx, Frank van Herpen, Nandini Raman, Miquel Lürling, Guido W. A. M. Waajen, Lisette de Senerpont Domis
    Harmful algal blooms are symptomatic of eutrophication and lead to deterioration of water quality and ecosystem services. Extreme climatic events could enhance eutrophication resulting in more severe nuisance algal blooms, while they also may hamper current restoration efforts aimed to reduce nutrient loads. Evaluation of restoration measures on their efficacy under climate change is essential for effective water management. We conducted a two-month mesocosm experiment in a hypertrophic urban canal focussing on the reduction of sediment phosphorus (P)-release. We tested the efficacy of four interventions, measuring phytoplankton biomass, nutrients in water and sediment. The measures included sediment dredging, water column aeration and application of P-sorbents (lanthanum-modified bentonite - Phoslock® and iron-lime sludge, a by-product from drinking water production). An extreme heatwave (with the highest daily maximum air temperature up to 40.7 °C) was recorded in the middle of our experiment. This extreme heatwave was used for the evaluation of heatwave-induced impacts. Dredging and lanthanum modified bentonite exhibited the largest efficacy in reducing phytoplankton and cyanobacteria biomass and improving water clarity, followed by iron-lime sludge, whereas aeration did not show an effect. The heatwave negatively impacted all four measures, with increased nutrient releases and consequently increased phytoplankton biomass and decreased water clarity compared to the pre-heatwave phase. We propose a conceptual model suggesting that the heatwave locks nutrients within the biological P loop, which is the exchange between labile P and organic P, while the P fraction in the chemical P loop will be decreased. As a consequence, the efficacy of chemical agents targeting P-reduction by chemical binding will be hampered by heatwaves. Our study indicates that current restoration measures might be challenged in a future with more frequent and intense heatwaves.
  • Landschap

    Het verondiepen van diepe uiterwaardplassen met slib

    Yvon J. M. Verstijnen, Piet-Jan Westendorp, Alfons J. P. Smolders, Lisette de Senerpont Domis, Sven Teurlincx, Gerben van Geest, Mark Groen, Martijn Dorenbosch, Paul van Els
    Door zand- en grindwinning zijn in het Nederlandse rivierenlandschap honderden diepe plassen ontstaan. Sommige van deze plassen worden verondiept met bagger en grond ten behoeve van natuurontwikkeling. Hiervoor wordt ook licht verontreinigd slib gebruikt. Dit verondiepen van diepe plassen leidt tot maatschappelijke weerstand. Voorstanders wijzen op de natuurwinst die kan ontstaan in verondiepte plassen, terwijl tegenstanders de waarde van de diepe plas benadrukken. Een belangrijk vraag is daarom in hoeverre verondiepen daadwerkelijk tot verbetering van de ecologie leidt.
  • RIO

    Securing Biodiversity, Functional Integrity, and Ecosystem Services in Drying River Networks (DRYvER)

    Thibault Datry, Daniel Allen, Roger Argelich, Jose Barquin, Nuria Bonada, Andrew Boulton, Flora Branger, Yongjiu Cai, Miguel Cañedo-Argüelles, Núria Cid, Zoltán Csabai, Martin Dallimer, José Carlos de Araújo, Steven A.J. Declerck, Thijs Dekker, Petra Döll, Andrea Encalada, Maxence Forcellini, Arnaud Foulquier, Jani Heino, Franck Jabot, Patrícia Keszler, Leena Kopperoinen, Sven Kralisch, Annika Künne, Nicolas Lamouroux, Claire Lauvernet, Virpi Lehtoranta, Barbora Loskotová, Rafael Marcé, Julia Martin Ortega, Christine Matauschek, Marko Miliša, Szilárd Mogyorósi, Nabor Moya, Hannes Müller Schmied, Antoni Munné, François Munoz, Heikki Mykrä, Irina Pal, Riikka Paloniemi, Petr Pařil, Polona Pengal, Bálint Pernecker, Marek Polášek, Carla Rezende, Sergi Sabater, Romain Sarremejane, Guido Schmidt, Lisette de Senerpont Domis, Gabriel Singer, Esteban Suárez, Matthew V. Talluto, Sven Teurlincx, Tim Trautmann, Amélie Truchy, Emmanouil Tyllianakis, Sari Väisänen, Liisa Varumo, Jean-Philippe Vidal, Annika Vilmi, Dolors Vinyoles
    River networks are among Earth’s most threatened hot-spots of biodiversity and provide key ecosystem services (e.g., supply drinking water and food, climate regulation) essential to sustaining human well-being. Climate change and increased human water use are causing more rivers and streams to dry, with devastating impacts on biodiversity and ecosystem services. Currently, more than a half of the global river networks consist of drying channels, and these are expanding dramatically. However, drying river networks (DRNs) have received little attention from scientists and policy makers, and the public is unaware of their importance. Consequently, there is no effective integrated biodiversity conservation or ecosystem management strategy of DRNs.A multidisciplinary team of 25 experts from 11 countries in Europe, South America, China and the USA will build on EU efforts to assess the cascading effects of climate change on biodiversity, ecosystem functions and ecosystem services of DRNs through changes in flow regimes and water use. DRYvER (DRYing riVER networks) will gather and upscale empirical and modelling data from nine focal DRNs (case studies) in Europe (EU) and Community of Latin American and Caribbean States (CELAC) to develop a meta-system framework applicable to Europe and worldwide. It will also generate crucial knowledge-based strategies, tools and guidelines for economically-efficient adaptive management of DRNs. Working closely with stakeholders and end-users, DRYvER will co-develop strategies to mitigate and adapt to climate change impacts in DRNs, integrating hydrological, ecological (including nature-based solutions), socio-economic and policy perspectives. The end results of DRYvER will contribute to reaching the objectives of the Paris Agreement and placing Europe at the forefront of research on climate change.
  • Water Research

    Characterizing 19 Thousand Chinese Lakes, Ponds and Reservoirs by Morphometric, Climate and Sediment Characteristics

    Annette B.G. Janssen, Bram Droppers, Xiangzhen Kong, Sven Teurlincx, Yindong Tong, Carolien Kroeze
    Chinese lakes, including ponds and reservoirs, are increasingly threatened by algal blooms. Yet, each lake is unique, leading to large inter-lake variation in lake vulnerability to algal blooms. Here, we aim to assess the effects of unique lake characteristics on lake vulnerability to algal blooms. To this end, we built a novel and comprehensive database of lake morphometric, climate and sediment characteristics of 19,536 Chinese lakes, including ponds and reservoirs (>0.1 km2). We assessed lake characteristics for nine stratification classes and show that lakes, including ponds and reservoirs, in eastern China typically have a warm stratification class (Tavg>4°C) and are slightly deeper than those in western China. Model results for representative lakes suggest that the most vulnerable lakes to algal blooms are in eastern China where pollution levels are also highest. Our characterization provides an important baseline to inform policymakers in what regions lakes are potentially most vulnerable to algal blooms.
  • Limnology and Oceanography

    Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

    Daphne Donis, Evanthia Mantzouki, Daniel F. McGinnis, Dominic Vachon, Irene Gallego, Hans-Peter Grossart, Lisette de Senerpont Domis, Sven Teurlincx, Laura Seelen, Miquel Lürling, Yvon J. M. Verstijnen, Valentini Maliaka, Jeremy Fonvielle, Petra M Visser, Jolanda Verspagen, Maria J Van Herk, Maria G. Antoniou, Nikoletta Tsiarta, Valerie McCarthy, Victor C. Perello, Danielle Machado-Vieira, Alinne Gurjão de Oliveira, Dubravka Špoljarić Maronić, Filip Stević, Tanja Žuna Pfeiffer, Itana Bokan Vucelić, Petar Žutinić, Marija Gligora Udovič, Anđelka Plenković-Moraj, Luděk Bláha, Rodan Geriš, Markéta Fránková, Kirsten Seestern Christoffersen, Trine Perlt Warming, Tõnu Feldmann, Alo Laas, Kristel Panksep, Lea Tuvikene, Kersti Kangro, Judita Koreivienė, Jūratė Karosienė, Jūratė Kasperovičienė, Ksenija Savadova-Ratkus, Irma Vitonytė, Kerstin Häggqvist, Pauliina Salmi, Lauri Arvola, Karl-Otto Rothhaupt, Christos Avagianos, Triantafyllos Kaloudis, Spyros Gkelis, Manthos Panou, Theodoros Triantis, Sevasti-Kiriaki Zervou, Anastasia Hiskia, Ulrike Obertegger, Adriano Boscaini, Giovanna Flaim, Nico Salmaso, Leonardo Cerasino, Sigrid Haande, Birger Skjelbred, Magdalena Grabowska, Maciej Karpowicz, Damian Chmura, Lidia Nawrocka, Justyna Kobos, Hanna Mazur-Marzec, Pablo Alcaraz-Párraga, Elżbieta Wilk-Woźniak, Wojciech Krztoń, Edward Walusiak, Ilona Gagala-Borowska, Joana Mankiewicz-Boczek, Magdalena Toporowska, Barbara Pawlik-Skowronska, Michał Niedźwiecki, Wojciech Pęczuła, Agnieszka Napiórkowska-Krzebietke, Julita Dunalska, Justyna Sieńska, Daniel Szymański, Marek Kruk, Agnieszka Budzyńska, Ryszard Goldyn, Anna Kozak, Joanna Rosińska, Elżbieta Szeląg-Wasielewska, Piotr Domek, Natalia Jakubowska-Krepska, Kinga Kwasizur, Beata Messyasz, Aleksandra Pełechata, Mariusz Pełechaty, Mikolaj Kokocinski, Beata Madrecka-Witkowska, Iwona Kostrzewska-Szlakowska, Magdalena Frąk, Agnieszka Bańkowska-Sobczak, Michał Wasilewicz, Agnieszka Ochocka, Agnieszka Pasztaleniec, Iwona Jasser, Ana M. Antão-Geraldes, Manel Leira, Vitor Vasconcelos, João Morais, Micaela Vale, Pedro M. Raposeiro, Vítor Gonçalves, Boris Aleksovski, Svetislav Krstić, Hana Nemova, Iveta Drastichova, Lucia Chomova, Spela Remec-Rekar, Tina Elersek, Lars-Anders Hansson, Pablo Urrutia-Cordero, Andrea G. Bravo, Moritz Buck, William Colom-Montero, Kristiina Mustonen, Don Pierson, Yang Yang, Jessica Richardson, Christine Edwards, Hannah Cromie, Jordi Delgado-Martín, David García-García, Jose Luís Cereijo, Joan Gomà, Mari Carmen Trapote, Teresa Vegas-Vilarrúbia, Biel Obrador, Ana García-Murcia, Monserrat Real, Elvira Romans, Jordi Noguero-Ribes, David Parreño Duque, Elísabeth Fernández-Morán, Bárbara Úbeda, José Ángel Gálvez, Núria Catalán, Carmen Pérez-Martínez, Eloísa Ramos-Rodríguez, Carmen Cillero-Castro, Enrique Moreno-Ostos, José María Blanco, Valeriano Rodríguez, Jorge Juan Montes-Pérez, Roberto L. Palomino, Estela Rodríguez-Pérez, Armand Hernández, Rafael Carballeira, Antonio Camacho, Antonio Picazo, Carlos Rochera, Anna C. Santamans, Carmen Ferriol, Susana Romo, Juan Miguel Soria, Arda Özen, Tünay Karan, Nilsun Demir, Meryem Beklioğlu, Nur Filiz, Eti E. Levi, Uğur Iskin, Gizem Bezirci, Ülkü Nihan Tavşanoğlu, Kemal Çelik, Koray Özhan, Nusret Karakaya, Mehmet Ali Turan Koçer, Mete Yilmaz, Faruk Maraşlıoğlu, Özden Fakioglu, Elif Neyran Soylu, Meral Apaydın Yağcı, Şakir Çınar, Kadir Çapkın, Abdulkadir Yağcı, Mehmet Cesur, Fuat Bilgin, Cafer Bulut, Rahmi Uysal, Latife Köker, Reyhan Akçaalan, Meriç Albay, Mehmet Tahir Alp, Korhan Özkan, Tuğba Ongun Sevindik, Hatice Tunca, Burçin Önem, Hans W. Paerl, Cayelan C. Carey, Bas Ibelings
    To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.
  • Limnology and Oceanography: Methods

    Flipping Lakes: Explaining concepts of catchment-scale water management through a serious game

    Maggie Armstrong, Lilith Kramer, Lisette de Senerpont Domis, Dianneke van Wijk, Alena Gsell, Wolf M. Mooij, Sven Teurlincx
    Ongoing anthropogenic and climatic pressures on inland waters have made water quality management a challenge of the 21st century. A holistic catchment-scale approach to water management which includes stakeholder participation will be a key in maintaining lake health. A first step toward community engagement is to bolster environmental literacy on lake management, ecology, and eutrophication concepts of stakeholders now and in future generations. However, communicating with nonwater professionals about effects of pollution on water quality and catchment-scale interactions across space and time can be difficult. Here, we present “Flipping Lakes,” a games-based method for lake professionals to communicate and educate about catchment-level water quality management to diverse audiences. In Flipping Lakes, the players take on the role of water managers in a catchment and are tasked to prevent a lake from “flipping” from a clear to a turbid state. During the game, the catchment slowly becomes polluted by a range of sources of which the effects are exacerbated by societal or climatic scenarios. Players need to implement measures while taking into consideration the intrinsic properties of the catchment in order to keep lakes clean. The game was tested with a diverse range of user groups and was well-received. With its entertaining and accessible content, Flipping Lakes can lower communication barriers and increase understanding of difficult water quality concepts. The game is highly customizable, making it applicable to a variety of settings to support education and engagement of stakeholders and the broader community in order to address local water challenges around the globe.
  • Progress in Photovoltaics : Research and Applications

    Innovative Floating Bifacial Photovoltaic Solutions for Inland Water Areas

    Hesan Ziar, Bjorn Prudon, Fen-Yu Lin, Bart Roeffen, Dennis Heijkoop, Tim Stark, Sven Teurlincx, Lisette de Senerpont Domis, Elias Garcia Goma, Julen Garro Extebarria, Ignacio Alavez, Daniel van Tilborg, Hein van Laar, Rudi Santberg, Olindo Isabella
    Photovoltaic (PV) technology has the potential to be integrated on many surfaces in various environments, even on water. Modeling, design, and realization of a floating PV system have more challenges than conventional rooftop or freestanding PV system. In this work, we introduce two innovative concepts for floating bifacial PV systems, describing their modeling, design, and performance monitoring. The developed concepts are retractable and enable maximum energy production through tracking the Sun. Various floating PV systems (monofacial, bifacial with and without reflectors) with different tilts and tracking capabilities are installed on a Dutch pond and are being monitored. Results of the thermal study showed that partially soaking the frame of PV modules into water does not bring a considerable additional yield (+0.17%) and revealed that floating PV modules experience higher temperature special variance compared with land‐based systems. Observations showed that the birds' presence has a severe effect on floating PV performance in the short term. Electrical yield investigation concluded that due to low albedo of inland water areas (~6.5%), bifacial PV systems must have reflectors. One‐year monitoring showed that a bifacial PV system with reflector and horizontal tracking delivers ~17.3% more specific yield (up to 29% in a clear‐sky month) compared with a monofacial PV system installed on land. Ecological monitoring showed no discernable impacts on the water quality in weekly samplings but did show significant impacts on the aquatic plant biomass and periods of low oxygen concentrations.
  • Science of the Total Environment

    The value of novel ecosystems: disclosing the ecological quality of quarry lakes

    Laura Seelen, Sven Teurlincx, John Bruinsma, Thea Huijsmans, Ellen Van Donk, Miquel Lürling, Lisette de Senerpont Domis
    Intense sand and gravel mining has created numerous man-made lakes around the world in the past century. These small quarry lakes (1–50 ha) are usually hydrologically isolated, often deep (6–40 m) and stratify during summer and in cold winters. Due to their small size, these deep man-made lakes are usually not included in the regular monitoring campaigns, e.g. as required for the European Water Framework Directive (WFD). Therefore, not much is known about the ecological functioning of these novel ecosystems. During two summers, we determined the macrophyte diversity and measured a range of physico-chemical and biological parameters in 51 quarry lakes in the catchment area of the rivers Meuse and Rhine. We compared the results of this campaign to the chemical and macrophyte sampling as performed for the WFD in the immediate surrounding shallow standing waters. Alpha (local) and beta diversity (regional), and local contribution to beta diversity were calculated for the whole region of which beta diversity was further partitioned into a true species replacement and richness difference component. Quarry lakes contain higher water quality reflected by lower nutrient and chlorophyll-a concentration compared with shallow water bodies. Additionally, quarry lakes contribute significantly to the regional macrophyte diversity pool by harboring distinctly different macrophyte communities (beta diversity — replacement). Specifically quarry lakes with a total phosphorus concentration in the water column below 35 μg P/l contribute most to beta diversity among quarry lakes. Novel ecosystems such as deep quarry lakes are often perceived as less valuable ecosystems, with strong implications regarding their management. Our results show that quarry lakes are in general of better chemical and biological quality compared with shallow standing waters. We therefore call for a more integrated assessment of the quality of quarry lakes and corresponding management strategy of these waters by water managers.
  • Proceedings of the International Association of Hydrological Sciences

    Integrated impact assessment of adaptive management strategies in a Dutch peatland polder

    Henk van Hardeveld, Harm de Jong, Maxim Knepflé, Thijs de Lange, Paul Schot, Bas Spanjers, Sven Teurlincx
    To achieve a more sustainable management of the subsiding Dutch peatlands, adaptations such as progressively higher surface water levels, pressurized field drains and a transition from dairy farming to paludiculture are considered. However, a clear understanding of implementation pathways for adaptive management strategies is lacking. Therefore, we used the RE:PEAT tool to elucidate the short-term and long-term impacts during 2025–2100 of two adaptive management strategies in Polder Zegveld and how to fairly distribute the costs and benefits of these strategies among the stakeholder groups. The strategies resulted in marked differences in soil subsidence and temporal trends in societal costs and benefits that affected stakeholders unequally. The
    adaptations were shown to reduce soil subsidence and enhance the sustainability of peatland management. We explored several options for a collective implementation of the adaptative management strategies. In addition, we discuss several ideas to further capitalize on the potential of the RE:PEAT tool to support peatland management. Currently, we are developing additional features that enable high spatio-temporal resolution simulations of the integrated dynamics of the surface water system, the shallow groundwater system, rainfall-runoff processes and solute transport. In combination with the PCDitch model, this will also enable detailed ecological assessments. This will pave the way for implementation pathways for adaptive management strategies that will contribute to a more sustainable peatland management.
  • Water

    Exploring How Cyanobacterial Traits Affect Nutrient Loading Thresholds in Shallow Lakes

    Manqi Chang, Sven Teurlincx, Jan H. Janse, Hans W. Paerl, Wolf M. Mooij, Annette B.G. Janssen
    Globally, many shallow lakes have shifted from a clear macrophyte-dominated state to a turbid phytoplankton-dominated state due to eutrophication. Such shifts are often accompanied by toxic cyanobacterial blooms, with specialized traits including buoyancy regulation and nitrogen fixation. Previous work has focused on how these traits contribute to cyanobacterial competitiveness. Yet, little is known on how these traits affect the value of nutrient loading thresholds of shallow lakes. These thresholds are defined as the nutrient loading at which lakes shift water quality state. Here, we used a modelling approach to estimate the effects of traits on nutrient loading thresholds. We incorporated cyanobacterial traits in the process-based ecosystem model PCLake+, known for its ability to determine nutrient loading thresholds. Four scenarios were simulated, including cyanobacteria without traits, with buoyancy regulation, with nitrogen fixation, and with both traits. Nutrient loading thresholds were obtained under N-limited, P-limited, and colimited conditions. Results show that cyanobacterial traits can impede lake restoration actions aimed at removing cyanobacterial blooms via nutrient loading reduction. However, these traits hardly affect the nutrient loading thresholds for clear lakes experiencing eutrophication. Our results provide references for nutrient loading thresholds and draw attention to cyanobacterial traits during the remediation of eutrophic water bodies.
  • Water Research

    Warming and CO2 effects under oligotrophication on temperate phytoplankton communities

    Marco J. Cabrerizo, M. Inmaculada Álvarez-Manzaneda, Elizabeth León-Palmero, Gerardo Guerrero-Jiménez, Lisette de Senerpont Domis, Sven Teurlincx, Juan M. González-Olalla
    Eutrophication, global warming, and rising carbon dioxide (CO2) levels are the three most prevalent pressures impacting the biosphere. Despite their individual effects are well-known, it remains untested how oligotrophication (i.e. nutrients reduction) can alter the planktonic community responses to warming and elevated CO2 levels. Here, we performed an indoor mesocosm experiment to investigate the warming × CO2 interaction under a nutrient reduction scenario (40%) mediated by an in-lake management strategy (i.e. addition of a commercial solid-phase phosphorus sorbent -Phoslock®) on a natural freshwater plankton community. Biomass production increased under warming × CO2 relative to present-day conditions; however, a Phoslock®-mediated oligotrophication reduced such values by 30–70%. Conversely, the warming × CO2 × oligotrophication interaction stimulated the photosynthesis by 20% compared to ambient nutrient conditions, and matched with higher resource use efficiency (RUE) and nutrient demand. Surprisingly, at a group level, we found that the multi-stressors scenario increased the photosynthesis in eukaryotes by 25%, but greatly impaired in cyanobacteria (ca. −25%). This higher cyanobacterial sensitivity was coupled with a reduced light harvesting efficiency and compensation point. Since Phoslock®-induced oligotrophication unmasked a strong negative warming × CO2 effect on cyanobacteria, it becomes crucial to understand how the interplay between climate change and nutrient abatement actions may alter the, ecosystems functioning. With an integrative understanding of these processes, policy makers will design more appropriate management strategies to improve the ecological status of aquatic ecosystems without compromising their ecological attributes and functioning.
  • Current Opinion in Environmental Sustainability

    Towards restoring urban waters: understanding the main pressures

    Sven Teurlincx, Jan J. Kuiper, Ellen C. M. Hoevenaar, Miquel Lürling, Bob Brederveld, Annelies Veraart, Annette B.G. Janssen, Wolf M. Mooij, Lisette de Senerpont Domis
    Water bodies in the urban landscape are omnipresent, with many being small, lentic waters such as ponds and lakes. Because of high anthropogenic forcing, these systems have poor water quality, with large consequences for the provisioning of ecosystem services. Understanding of the main pressures on urban water quality is key to successful management. We identify six pressures that we hypothesize to have strong links to anthropogenic forcing including: eutrophication, aquatic invasive species, altered hydrology, altered habitat structure, climate change, and micropollutants. We discuss how these pressures may affect water quality and ecological functioning of urban waters. We describe how these pressures may interact, posing challengers for water management. We identify steps that need to be taken towards sustainable restoration, recognizing the challenges that potentially interacting pressures pose to water managers.
  • Ecological Modelling

    PCLake +: a process-based ecological model to assess the trophic state of stratified and non-stratified freshwater lakes worldwide

    Annette B.G. Janssen, Sven Teurlincx, Arthur HW Beusen, M.A.J. Huijbregts, Jasmijn Rost, Aafke M. Schipper, Laura Seelen, Wolf M. Mooij, Jan H. Janse
    The lake ecosystem model PCLake is a process-based model that was developed to simulate water quality based on ecological interactions in shallow, non-stratifying lakes in the temperate climate zone. Here we present PCLake+, which extends the PCLake model to cover a wide range of freshwater lakes that differ in stratification regime and climate-related processes. To this end, the model was extended with a hypolimnion layer that can be invoked and configured by forcing functions or by simple built-in empirical relationships that impose stratification. Further adjustments to the original PCLake model have been made with respect to the calculation of 1) light irradiation in the water column, 2) evaporation processes and 3) phenology of macrophytes. The simulation output of PCLake+ for different types of lakes complies well with generally accepted limnological knowledge, thus holding promise for future contributions to ecological theory and application to lakes around the globe.
  • Water Research

    Modelling induced bank filtration effects on freshwater ecosystems to ensure sustainable drinking water production

    Mikael Gillefalk, Wolf M. Mooij, Sven Teurlincx, Annette B.G. Janssen, Jan H. Janse, Manqi Chang, Jan Köhler, Sabine Hilt
    Induced bank filtration (IBF) is a water abstraction technology using different natural infiltration systems for groundwater recharge, such as river banks and lake shores. It is a cost-effective pre-treatment method for drinking water production used in many regions worldwide, predominantly in urban areas. Until now, research concerning IBF has almost exclusively focussed on the purification efficiency and infiltration capacity. Consequently, knowledge about the effects on source water bodies is lacking. Yet, IBF interrupts groundwater seepage and affects processes in the sediment potentially resulting in adverse effects on lake or river water quality. Securing sufficient source water quality, however, is important for a sustainable drinking water production by IBF. In this study, we analysed the effects of five predicted mechanisms of IBF on shallow lake ecosystems using the dynamic model PCLake: declining CO2 and nutrient availability, as well as increasing summer water temperatures, sedimentation rates and oxygen penetration into sediments. Shallow lake ecosystems are abundant worldwide and characterised by the occurrence of alternative stable states with either clear water and macrophyte dominance or turbid, phytoplankton-dominated conditions. Our results show that IBF in most scenarios increased phytoplankton abundance and thus had adverse effects on shallow lake water quality. Threshold levels for critical nutrient loading inducing regime shifts from clear to turbid conditions were up to 80% lower with IBF indicating a decreased resilience to eutrophication. The effects were strongest when IBF interrupted the seepage of CO2 rich groundwater resulting in lower macrophyte growth. IBF could also enhance water quality, but only when interrupting the seepage of groundwater with high nutrient concentrations. Higher summer water temperatures increased the share of cyanobacteria in the phytoplankton community and thus the risk of toxin production. In relative terms, the effects of changing sedimentation rates and oxygen penetration were small. Lake depth and size influenced the effect of IBF on critical nutrient loads, which was strongest in shallower and smaller lakes. Our model results stress the need of a more comprehensive ecosystem perspective including an assessment of IBF effects on threshold levels for regime shifts to prevent high phytoplankton abundance in the source water body and secure a sustainable drinking water supply.
  • Current Opinion in Environmental Sustainability

    Modeling water quality in the Anthropocene: Directions for the next-generation aquatic ecosystem models

    Wolf M. Mooij, Dianneke van Wijk, Arthur HW Beusen, Bob Brederveld, Manqi Chang, Marleen Cobben, D.L. DeAngelis, Andrea S. Downing, Pamela Green, Alena Gsell, Inese Huttunen, Jan H. Janse, Annette B.G. Janssen, Geerten Hengeveld, Xiangzhen Kong, Lilith Kramer, Jan J. Kuiper, Simon J. Langan, Bart A. Nolet, Rascha Nuijten, Maryna Strokal, Tineke A. Troost, A.M. van Dam, Sven Teurlincx
    “Everything changes and nothing stands still” (Heraclitus). Here we review three major improvements to freshwater aquatic ecosystem models — and ecological models in general — as water quality scenario analysis tools towards a sustainable future. To tackle the rapid and deeply connected dynamics characteristic of the Anthropocene, we argue for the inclusion of eco-evolutionary, novel ecosystem and social-ecological dynamics. These dynamics arise from adaptive responses in organisms and ecosystems to global environmental change and act at different integration levels and different time scales. We provide reasons and means to incorporate each improvement into aquatic ecosystem models. Throughout this study we refer to Lake Victoria as a microcosm of the evolving novel social-ecological systems of the Anthropocene. The Lake Victoria case clearly shows how interlinked eco-evolutionary, novel ecosystem and social-ecological dynamics are, and demonstrates the need for transdisciplinary research approaches towards global sustainability.
  • Water Research

    An affordable and reliable assessment of aquatic decomposition: Tailoring the Tea Bag Index to surface waters

    Laura Seelen, Giovanna Flaim, Joost Keuskamp, Sven Teurlincx, Raquel Arias Font, Duygu Tolunay, Markéta Fránková, Kateřina Šumberová, Maria Temponeras, Mirjana Lenhardt, Eleanor Jennings, Lisette de Senerpont Domis
    Litter decomposition is a vital part of the global carbon cycle as it determines not only the amount of carbon to be sequestered, but also how fast carbon re-enters the cycle. Freshwater systems play an active role in the carbon cycle as it receives, and decomposes, terrestrial litter material alongside decomposing aquatic plant litter. Decomposition of organic matter in the aquatic environment is directly controlled by water temperature and nutrient availability, which are continuously affected by global change. We adapted the Tea Bag Index (TBI), a highly standardized methodology for determining soil decomposition, for lakes by incorporating a leaching factor. By placing Lipton pyramid tea bags in the aquatic environment for 3 hours, we quantified the period of intense leaching which usually takes place prior to litter (tea) decomposition. Standard TBI methodology was followed after this step to determine how fast decomposition takes place (decomposition rate, k1) and how much of the material cannot be broken down and is thus sequestered (stabilization factor, S). A Citizen Science project was organized to test the aquatic TBI in 40 European lakes located in four climate zones, ranging from oligotrophic to hypereutrophic systems. We expected that warmer and/or eutrophic lakes would have a higher decomposition rate and a more efficient microbial community resulting in less tea material to be sequestered. The overall high decomposition rates (k1) found confirm the active role lakes play in the global carbon cycle. Across climate regions the lakes in the warmer temperate zone displayed a higher decomposition rate (k1) compared to the colder lakes in the continental and polar zones. Across trophic states, decomposition rates were higher in eutrophic lakes compared to oligotrophic lakes. Additionally, the eutrophic lakes showed a higher stabilization (S), thus a less efficient microbial community, compared to the oligotrophic lakes, although the variation within this group was high. Our results clearly show that the TBI can be used to adequately assess the decomposition process in aquatic systems. Using “alien standard litter” such as tea provides a powerful way to compare decomposition across climates, trophic states and ecosystems. By providing standardized protocols, a website, as well as face to face meetings, we also showed that collecting scientifically relevant data can go hand in hand with increasing scientific and environmental literacy in participants. Gathering process-based information about lake ecosystems gives managers the best tools to anticipate and react to future global change. Furthermore, combining this process-based information with citizen science, thus outreach, is in complete agreement with the Water Framework Directive goals as set in 2010.
  • Science of the Total Environment

    Effect of river restoration on life-history strategies in fish communities

    Alessandro Manfrin, Sven Teurlincx, Armin W. Lorenz, Peter Haase, Maare Marttila, Jukka Syrjänen, Gregor Thomas, Stefan Stoll
  • Current Opinion in Environmental Sustainability

    How to model algal blooms in any lake on earth

    Annette B.G. Janssen, Jan H. Janse, Arthur HW Beusen, Manqi Chang, John A Harrison, Inese Huttunen, Xiangzhen Kong, Jasmijn Rost, Sven Teurlincx, Tineke A. Troost, Dianneke van Wijk, Wolf M. Mooij
    Algal blooms increasingly threaten lake and reservoir water quality at the global scale, caused by ongoing climate change and nutrient loading. To anticipate these algal blooms, models to project future algal blooms worldwide are required. Here we present the state-of-the-art in algal projection modelling and explore the requirements of an ideal algal projection model. Based on this, we identify current challenges and opportunities for such model development. Since most building blocks are present, we foresee that algal projection models for any lake on earth can be developed in the near future. Finally, we think that algal bloom projection models at a global scale will provide a valuable contribution to global policymaking, in particular with respect to SDG 6 (clean water and sanitation).
  • Science of the Total Environment

    A generically parameterized model of Lake eutrophication (GPLake) that links field-, lab- and model-based knowledge

    Manqi Chang, Sven Teurlincx, Donald L. DeAngelis, Jan H. Janse, Tineke A. Troost, Dianneke van Wijk, Wolf M. Mooij, Annette B.G. Janssen
    Worldwide, eutrophication is threatening lake ecosystems. To support lake management numerous eutrophication models have been developed. Diverse research questions in a wide range of lake ecosystems are addressed by these models. The established models are based on three key approaches: the empirical approach that employs field surveys, the theoretical approach in which models based on first principles are tested against lab experiments, and the process-based approach that uses parameters and functions representing detailed biogeochemical processes. These approaches have led to an accumulation of field-, lab- and model-based knowledge, respectively. Linking these sources of knowledge would benefit lake management by exploiting complementary information; however, the development of a simple tool that links these approaches was hampered by their large differences in scale and complexity. Here we propose a Generically Parameterized Lake eutrophication model (GPLake) that links field-, lab- and model-based knowledge and can be used to make a first diagnosis of lake water quality. We derived GPLake from consumer-resource theory by the principle that lacustrine phytoplankton is typically limited by two resources: nutrients and light. These limitations are captured in two generic parameters that shape the nutrient to chlorophyll-a relations. Next, we parameterized GPLake, using knowledge from empirical, theoretical, and process-based approaches. GPLake generic parameters were found to scale in a comparable manner across data sources. Finally, we show that GPLake can be applied as a simple tool that provides lake managers with a first diagnosis of the limiting factor and lake water quality, using only the parameters for lake depth, residence time and current nutrient loading. With this first-order assessment, lake managers can easily assess measures such as reducing nutrient load, decreasing residence time or changing depth before spending money on field-, lab- or model- experiments to support lake management.
  • Current Opinion in Environmental Sustainability

    A perspective on water quality in connected systems: modelling feedback between upstream and downstream transport and local ecological processes

    Sven Teurlincx, Dianneke van Wijk, Wolf M. Mooij, Jan J. Kuiper, Inese Huttunen, Bob Brederveld, Manqi Chang, Jan H. Janse, Ben Woodward, Fenjuan Hu, Annette B.G. Janssen
    Food production for a growing world population relies on application of fertilisers and pesticides on agricultural lands. However, these substances threaten surface water quality and thereby endanger valued ecosystem services such as drinking water supply, food production and recreational water use. Such deleterious effects do not merely arise on the local scale, but also on the regional scale through transport of substances as well as energy and biota across the catchment. Here we argue that aquatic ecosystem models can provide a process-based understanding of how these transports by water and organisms as vectors affect – and are affected by – ecosystem state and functioning in networks of connected lakes. Such a catchment scale approach is key to setting critical limits for the release of substances by agricultural practices and other human pressures on aquatic ecosystems. Thereby, water and food production and the trade-offs between them may be managed more sustainably.
  • Toxins

    Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

    Evanthia Mantzouki, Miquel Lürling, Jutta Fastner, Lisette de Senerpont Domis, Elżbieta Wilk-Woźniak, Judita Koreivienė, Laura Seelen, Sven Teurlincx, Yvon J. M. Verstijnen, Wojciech Krztoń, Edward Walusiak, Jūratė Karosienė, Jūratė Kasperovičienė, Ksenija Savadova, Irma Vitonytė, Carmen Cillero-Castro, Agnieszka Budzyńska, Ryszard Goldyn, Anna Kozak, Joanna Rosińska, Elżbieta Szeląg-Wasielewska, Piotr Domek, Natalia Jakubowska-Krepska, Kinga Kwasizur, Beata Messyasz, Aleksandra Pełechata, Mariusz Pełechaty, Mikolaj Kokocinski, Ana García-Murcia, Monserrat Real, Elvira Romans, Jordi Noguero-Ribes, David Parreño Duque, Elísabeth Fernández-Morán, Nusret Karakaya, Kerstin Häggqvist, Nilsun Demir, Meryem Beklioğlu, Nur Filiz, Eti E. Levi, Uğur Iskin, Gizem Bezirci, Ülkü Nihan Tavşanoğlu, Koray Özhan, Spyros Gkelis, Manthos Panou, Özden Fakioglu, Christos Avagianos, Triantafyllos Kaloudis, Kemal Çelik, Mete Yilmaz, Rafael Marcé, Núria Catalán, Andrea G. Bravo, Moritz Buck, William Colom-Montero, Kristiina Mustonen, Don Pierson, Yang Yang, Pedro M. Raposeiro, Vítor Gonçalves, Maria G. Antoniou, Nikoletta Tsiarta, Valerie McCarthy, Victor C. Perello, Tõnu Feldmann, Alo Laas, Kristel Panksep, Lea Tuvikene, Ilona Gagala, Joana Mankiewicz-Boczek, Meral Apaydın Yağcı, Şakir Çınar, Kadir Çapkın, Abdulkadir Yağcı, Mehmet Cesur, Fuat Bilgin, Cafer Bulut, Rahmi Uysal, Ulrike Obertegger, Adriano Boscaini, Giovanna Flaim, Nico Salmaso, Leonardo Cerasino, Jessica Richardson, Petra M Visser, Jolanda Verspagen, Tünay Karan, Elif Neyran Soylu, Faruk Maraşlıoğlu, Agnieszka Napiórkowska-Krzebietke, Agnieszka Ochocka, Agnieszka Pasztaleniec, Ana M. Antão-Geraldes, Vitor Vasconcelos, João Morais, Micaela Vale, Latife Köker, Reyhan Akçaalan, Meriç Albay, Dubravka Špoljarić Maronić, Filip Stević, Tanja Žuna Pfeiffer, Jeremy Fonvielle, Dietmar Straile, Karl-Otto Rothhaupt, Lars-Anders Hansson, Pablo Urrutia-Cordero, Luděk Bláha, Rodan Geriš, Markéta Fránková, Mehmet Ali Turan Koçer, Mehmet Tahir Alp, Spela Remec-Rekar, Tina Elersek, Theodoros Triantis, Sevasti-Kiriaki Zervou, Anastasia Hiskia, Sigrid Haande, Birger Skjelbred, Beata Madrecka, Hana Nemova, Iveta Drastichova, Lucia Chomova, Christine Edwards, Tuğba Ongun Sevindik, Hatice Tunca, Burçin Önem, Boris Aleksovski, Svetislav Krstić, Itana Bokan Vucelić, Lidia Nawrocka, Pauliina Salmi, Danielle Machado-Vieira, Alinne Gurjão de Oliveira, Jordi Delgado-Martín, David García-García, Jose Luís Cereijo, Joan Gomà, Mari Carmen Trapote, Teresa Vegas-Vilarrúbia, Biel Obrador, Magdalena Grabowska, Maciej Karpowicz, Damian Chmura, Bárbara Úbeda, José Ángel Gálvez, Arda Özen, Kirsten Seestern Christoffersen, Trine Perlt Warming, Justyna Kobos, Hanna Mazur-Marzec, Carmen Pérez-Martínez, Eloísa Ramos-Rodríguez, Lauri Arvola, Pablo Alcaraz-Párraga, Magdalena Toporowska, Barbara Pawlik-Skowronska, Michał Niedźwiecki, Wojciech Pęczuła, Manel Leira, Armand Hernández, Enrique Moreno-Ostos, José María Blanco, Valeriano Rodríguez, Jorge Juan Montes-Pérez, Roberto L. Palomino, Estela Rodríguez-Pérez, Rafael Carballeira, Antonio Camacho, Antonio Picazo, Carlos Rochera, Anna C. Santamans, Carmen Ferriol, Susana Romo, Juan Miguel Soria, Julita Dunalska, Justyna Sieńska, Daniel Szymański, Marek Kruk, Iwona Kostrzewska-Szlakowska, Iwona Jasser, Petar Žutinić, Marija Gligora Udovič, Anđelka Plenković-Moraj, Magdalena Frąk, Agnieszka Bańkowska-Sobczak, Michał Wasilewicz, Korhan Özkan, Valentini Maliaka, Kersti Kangro, Hans-Peter Grossart, Hans W. Paerl, Cayelan C. Carey, Bas Ibelings
    situ Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.
  • Frontiers in Plant Science

    Response of Submerged Macrophyte Communities to External and Internal Restoration Measures in North Temperate Shallow Lakes

    Sabine Hilt, Marta M. Alirangues Nuñez, (Liesbeth) E.S. Bakker, Irmgard Blindow, Thomas A. Davidson, Mikael Gillefalk, Lars-Anders Hansson, Jan H. Janse, Annette B.G. Janssen, Erik Jeppesen, Timm Kabus, Andrea Kelly, Jan Köhler, Torben L. Lauridsen, Wolf M. Mooij, Ruurd Noordhuis, Geoff Phillips, Jacqueline Rücker, Hans-Heinrich Schuster, Martin Søndergaard, Sven Teurlincx, Klaus van de Weyer, Ellen Van Donk, Arno Waterstraat, Nigel J. Willby, Carl D. Sayer
    Submerged macrophytes play a key role in north temperate shallow lakes by stabilising clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analysed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterised by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterised by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallow areas, germinate early in spring, have energy-rich vegetative propagules facilitating rapid initial growth and that can complete their life cycle by early summer. Later in the growing season these plants are, according to our simulations, outcompeted by periphyton, leading to late-summer phytoplankton blooms. Internal lake restoration measures often coincide with a rapid but transient colonisation by hornworts, waterweeds or charophytes. Stable clear-water conditions and a diverse macrophyte flora only occurred decades after external nutrient load reduction or when measures were combined.
  • Frontiers in Microbiology

    Local functioning, landscape structuring: drivers of soil microbial community structure and function in peatlands

    Sven Teurlincx, Amber Heijboer, Annelies Veraart, George Kowalchuk, Steven A.J. Declerck
    Agricultural peatlands are essential for a myriad of ecosystem functions and play an important role in the global carbon (C) cycle through C sequestration. Management of these agricultural peatlands takes place at different spatial scales, ranging from local to landscape management, and drivers of soil microbial community structure and function may be scale-dependent. Effective management for an optimal biogeochemical functioning thus requires knowledge of the drivers on soil microbial community structure and functioning, as well as the spatial scales upon which they are influenced. During two field campaigns, we examined the importance of different drivers (i.e., soil characteristics, nutrient management, vegetation composition) at two spatial scales (local vs. landscape) for, respectively, the soil microbial community structure (determined by PLFA) and soil microbial community functional capacity (as assessed by CLPP) in agricultural peatlands. First, we show by an analysis of PLFA profiles that the total microbial biomass changes with soil moisture and relative C:P nutrient availability. Secondly, we showed that soil communities are controlled by a distinct set of drivers at the local, as opposed to landscape, scale. Community structure was found to be markedly different between areas, in contrast to community function which showed high variability within areas. We further found that microbial structure appears to be controlled more at a landscape scale by nutrient-related variables, whereas microbial functional capacity is driven locally through plant community feedbacks. Optimal management strategies within such peatlands should therefore consider the scale-dependent action of soil microbial community drivers, for example by first optimizing microbial structure at the landscape scale by targeted areal management, and then optimizing soil microbial function by local vegetation management.
  • Ecology Letters

    Species sorting and stoichiometric plasticity control community C:P ratio of first-order aquatic consumers

    Sven Teurlincx, Mandy Velthuis, D. Seroka, Lynn Govaert, Ellen Van Donk, Dedmer Van de Waal, Steven A.J. Declerck
    Ecological stoichiometry has proven to be invaluable for understanding consumer response to changes in resource quality. Although interactions between trophic levels occur at the community level, most studies focus on single consumer species. In contrast to individual species, communities may deal with trophic mismatch not only through elemental plasticity but also through changes in species composition. Here, we show that a community of first-order consumers (e.g. zooplankton) is able to adjust its stoichiometry (C:P) in response to experimentally induced changes in resource quality, but only to a limited extent. Furthermore, using the Price equation framework we show the importance of both elemental plasticity and species sorting. These results illustrate the need for a community perspective in ecological stoichiometry, requiring consideration of species-specific elemental composition, intraspecific elemental plasticity and species turnover.
  • Applied Soil Ecology

    Exploring the reservoir of potential fungal plant pathogens in agricultural soil

    Maaike Van Agtmaal, Angie Straathof, Aad J Termorshuizen, Sven Teurlincx, M.P.J. Hundscheid, S Ruyters, P. Busschaert, Bart Lievens, Wietse de Boer
    Soil-borne pathogens cause great crop losses in agriculture. Because of their resilience in the soil, these pathogens persist in a population reservoir, causing future outbreaks of crop diseases. Management focus is usually on the most common pathogens occurring, but it is likely that a mixed population of pathogens together affect crops. Next generation sequencing of DNA from environmental samples can provide information on the presence of potential pathogens. The aim of this study was to obtain insight into the factors that drive the composition of potential plant pathogen populations in agricultural soils. To this end, the alpha and beta diversity of fungal OTUs that were assigned as potential plant pathogens for 42 agricultural soils were assessed. The presented study is the first inventory of the pool of pathogens and its correlating factors. The results of this inventory indicate that the composition of pathogens in soil is driven by pH, soil type, crop history, litter saprotrophic fungi and spatial patterns. The major driving factors differed between potential root- and shoot-infecting fungi, suggesting interactions among environmental factors and pathogen traits like reproduction, survival and dispersal. This information is important to understand risks for disease outbreaks and to recommend management strategies to prevent such outbreaks.
  • Aquatic Ecology

    Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective

    Annette B.G. Janssen, George B. Arhonditsis, Arthur HW Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, Rene Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij
    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of existing models. Finally, we discuss how model diversity came about in the past and could evolve in the future. Throughout our study, we use analogies from biodiversity research to analyse and interpret model diversity. We recommend to make models publicly available through open-source policies, to standardize documentation and technical implementation of models, and to compare models through ensemble modelling and interdisciplinary approaches. We end with our perspective on how the field of aquatic ecosystem modelling might develop in the next 5–10 years. To strive for clarity and to improve readability for non-modellers, we include a glossary.
  • Fundamental and Applied Limnology

    Advantages of concurrent use of multiple software frameworks in water quality modelling using a database approach

    Luuk P.A. Van Gerven, Bob Brederveld, Jeroen J.M. de Klein, D.L. DeAngelis, Andrea S. Downing, M. Faber, Daan J. Gerla, J. 't Hoen, Jan H. Janse, Annette B.G. Janssen, M. Jeuken, B.W. Kooi, Jan J. Kuiper, B. Lischke, S. Liu, Thomas Petzoldt, S.A. Schep, Sven Teurlincx, C. Thiange, D. Trolle, Egbert H. van Nes, Wolf M. Mooij
  • Journal of Great Lakes Research

    Alternative stable states in large shallow lakes?

    Annette B.G. Janssen, Sven Teurlincx, S.Q. An, Jan H. Janse, Hans W. Paerl, Wolf M. Mooij
    Many lakes worldwide are experiencing great change due to eutrophication. Consequently, species composition changes, toxic algal blooms proliferate, and drinking water supplies dwindle. The transition to the deteriorated state can be catastrophic with an abrupt change from macrophyte to phytoplankton domination. This has been shown repeatedly in small lakes. Whether such alternative stable states also exist in large shallow lakes is less clear, however. Here we discuss the characteristics that give rise to alternative stable states in large shallow lakes either in the lake as whole or restricted to specific regions of the lake. We include the effect of lake size, spatial heterogeneity and internal connectivity on a lake's response along the eutrophication axis. As a case study, we outline the eutrophication history of Lake Taihu (China) and illustrate how lake size, spatial heterogeneity and internal connectivity can explain the observed spatial presence of different states. We discuss whether these states can be alternatively stable by comparing the data with model output (PCLake). These findings are generalised for other large, shallow lakes. We conclude that locations with prevailing size effects generally lack macrophytes; and, therefore, alternative stable states are unlikely to occur there. However, most large shallow lakes have macrophytes whose presence remains unexplained when only size effect is taken into account. By including spatial heterogeneity in the analysis, the presence of macrophytes and alternative stable states in large shallow lakes is better understood. Finally, internal connectivity is important because a high internal connectivity reduces the stability of alternative states.
  • Wetlands Ecology and Management

    The impact of river regulation on the biodiversity intactness of floodplain wetlands

    Jan J. Kuiper, Jan H. Janse, Sven Teurlincx, Jos T.A. Verhoeven, Rob Alkemade
    Alteration of natural flow regime is considered a major threat to biodiversity in river floodplain ecosystems. Measurements of quantitative relationships between flow regime change and biodiversity are, however, incomplete and inconclusive. This hampers the assessment of human impact on riverine floodplain wetlands in global biodiversity evaluations. We systematically reviewed the scientific literature and extracted information from existing data sets for a meta-analysis to unravel a general quantitative understanding of the ecological consequences of altered flow regimes. From 28 studies we retrieved both ecological and hydrological data. Relative mean abundance of original species (mean species abundance, MSA) and relative species richness were used as effect size measures of biodiversity intactness. The meta-analysis showed that alteration of a natural flow regime reduces the MSA by more than 50 % on average, and species richness by more than 25 %. Impact on species richness and abundance tends to be related to the degree of hydrological alteration. These results can be used in strategic quantitative assessments by incorporating the relationships into global models on environmental change and biodiversity such as GLOBIO-aquatic.
  • Environmental Modelling and Software

    Serving many at once: How a database approach can create unity in dynamical ecosystem modelling

    Wolf M. Mooij, Bob Brederveld, J.J.M de Klein, D.L. DeAngelis, Andrea S. Downing, M. Faber, Daan J. Gerla, M.R. Hipsey, J. 't Hoen, Jan H. Janse, Annette B.G. Janssen, M. Jeuken, B.W. Kooi, B. Lischke, T. Petzoldt, L. Postma, S.A. Schep, Huub Scholten, Sven Teurlincx, C. Thiange, D. Trolle, Anne A. van Dam, Luuk P.A. Van Gerven, E.H. Van Nes, Jan J. Kuiper
    Simulation modelling in ecology is a field that is becoming increasingly compartmentalized. Here we propose a Database Approach To Modelling (DATM) to create unity in dynamical ecosystem modelling with differential equations. In this approach the storage of ecological knowledge is independent of the language and platform in which the model will be run. To create an instance of the model, the information in the database is translated and augmented with the language and platform specifics. This process is automated so that a new instance can be created each time the database is updated. We describe the approach using the simple Lotka–Volterra model and the complex ecosystem model for shallow lakes PCLake, which we automatically implement in the frameworks OSIRIS, GRIND for MATLAB, ACSL, R, DUFLOW and DELWAQ. A clear advantage of working in a database is the overview it provides. The simplicity of the approach only adds to its elegance.

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