TY - JOUR T1 - Comparing the effects of climate and land use on surface water quality using future watershed scenarios JF - Science of the Total Environment Y1 - 2019 A1 - Motew, Melissa A1 - Chen, Xi A1 - Carpenter, Stephen R. A1 - Booth, Eric G. A1 - Seifert, Jenny A1 - Qiu, Jiangxiao A1 - Loheide, Steven P. A1 - Turner, Monica G. A1 - Zipper, Samuel C. A1 - Kucharik, Christopher J. KW - climate KW - land use KW - Manure KW - phosphorus KW - Surface water quality KW - Watershed AB - Eutrophication of freshwaters occurs in watersheds with excessive pollution of phosphorus (P). Factors that affect P cycling and transport, including climate and land use, are changing rapidly and can have legacy effects, making future freshwater quality uncertain. Focusing on the Yahara Watershed (YW) of southern Wisconsin, USA, an intensive agricultural landscape, we explored the relative influence of land use and climate on three indicators of water quality over a span of 57 years (2014–2070). The indicators included watershed-averaged P yield from the land surface, direct drainage P loads to a lake, and average summertime lake P concentration. Using biophysical model simulations of future watershed scenarios, we found that climate exerted a stronger influence than land use on all three indicators, yet land use had an important role in influencing long term outcomes for each. Variations in P yield due to land use exceeded those due to climate in 36 of 57 years, whereas variations in load and lake total P concentration due to climate exceeded those due to land use in 54 of 57 years, and 52 of 57 years, respectively. The effect of land use was thus strongest for P yield off the landscape and attenuated in the stream and lake aquatic systems where the influence of weather variability was greater. Overall these findings underscore the dominant role of climate in driving inter-annual nutrient fluxes within the hydrologic network and suggest a challenge for land use to influence water quality within streams and lakes over timescales less than a decade. Over longer timescales, reducing applications of P throughout the watershed was an effective management strategy under all four climates investigated, even during decades with wetter conditions and more frequent extreme precipitation events. VL - 693 SN - 0048-9697 UR - http://www.sciencedirect.com/science/article/pii/S0048969719334047 ER - TY - JOUR T1 - Management of minimum lake levels and impacts on flood mitigation: A case study of the Yahara Watershed, Wisconsin, USA JF - Journal of Hydrology Y1 - 2019 A1 - Chen, Xi A1 - Motew, Melissa M. A1 - Booth, Eric G. A1 - Zipper, Samuel C. A1 - Loheide, Steven P. A1 - Kucharik, Christopher J. KW - ecosystem services KW - Flood exposure assessment KW - Hydrologic model KW - Lake level management AB - Lake level regulation is commonly used to manage water resources and mitigate flood risk in watersheds with linked river–lake systems. In this study, we first assess exposure, in terms of both population and land area, to flooding impacts in the Yahara Watershed’s chain of four lakes in southern Wisconsin as affected by minimum lake level management. A flooding exposure assessment shows that the areas surrounding the upstream lakes, Mendota and Monona, have dense urban areas with high populations that are exposed to flooding; Waubesa has low elevations along its lakeshore, resulting in a large potential flooding area; and the most downstream lake, Kegonsa, has a large area of surrounding cropland that is exposed to flooding but impacts a limited population. We then use a linked modeling framework of a land surface model (Agro-IBIS) and a hydrologic-routing model (THMB) to simulate daily lake level over a study period of 1994–2013 in the Yahara Watershed with different minimum lake level management strategies. Modeling results show that the peak lake levels and corresponding exposed land area and population to flooding will decrease under a lower target minimum lake level. However, at the same time, the number of days that the lake level is below winter minimum will increase, which may adversely affect ecosystem health. In addition, our sensitivity analysis indicates that reducing target minimum lake levels will help mitigate flood risk in terms of both flood magnitude and frequency. Nevertheless, this must be balanced against the need to maintain adequately high lake levels for ecosystem services and recreational functions of the lakes. VL - 577 SN - 0022-1694 UR - http://www.sciencedirect.com/science/article/pii/S0022169419306407 JO - Journal of Hydrology ER - TY - JOUR T1 - Nonlinear groundwater influence on biophysical indicators of ecosystem services JF - Nature Sustainability Y1 - 2019 A1 - Qiu, Jiangxiao A1 - Zipper, Samuel C. A1 - Motew, Melissa A1 - Booth, Eric G. A1 - Kucharik, Christopher J. A1 - Loheide, Steven P. AB - Groundwater is a fundamental control on biophysical processes underpinning essential ecosystem services (ES). However, interactions and feedbacks among groundwater, climate and multiple ES remain less well understood. We investigated groundwater effects on a portfolio of food, water and biogeochemical ES indicators in an urbanizing agricultural watershed. Our results show that food production, water quality and quantity, and flood control are most sensitive to groundwater, with the strongest responses under wet and dry climate extremes. Climate mediates groundwater effects, such that several ES have synergies during dry climate, but trade-offs (groundwater increased some ES but declined others) under wet climate. There is substantial spatial heterogeneity in groundwater effects on ES, which is driven primarily by water table depth (WTD) and is also sensitive to soil texture and land cover. Most ES indicators respond nonlinearly to WTD when groundwater is within a critical depth (approximately 2.5 m) of land surface, indicating that small WTD changes can have disproportionately large effects on ES in shallow groundwater areas. Within this critical WTD, increasingly shallow groundwater leads to nonlinear increases in surface flood risk, sediment erosion and phosphorus yield; nonlinear decreases in drainage to the deep vadose zone and thus groundwater recharge; and bidirectional responses of crop and grass production, carbon storage and nitrate leaching. Our study illustrates the complex role of groundwater in affecting multiple ES and highlights that strategically managing groundwater may enhance ES resilience to climate extremes in shallow groundwater settings. SN - 2398-9629 UR - https://doi.org/10.1038/s41893-019-0278-2 JO - Nature Sustainability ER - TY - JOUR T1 - Effects of Root Distribution and Root Water Compensation on Simulated Water Use in Maize Influenced by Shallow Groundwater JF - Vadose Zone Journal Y1 - 2017 A1 - Soylu, Mehmet Evren A1 - Loheide, Steven P. A1 - Kucharik, Christopher J. AB - We investigated the potential impacts of shallow groundwater, root length density (RLD) distribution, and root water compensation on transpiration and net primary productivity (NPP). An agroecosystem model (AgroIBIS-VSF) that is capable of simulating variably saturated water flow was driven with hourly weather observations in southern Wisconsin over 27 yr for various RLD distributions across a continuum of groundwater depth. The results indicated that the strength of the relationship between groundwater depth and water use in the critical water table depth zone is controlled by the root structure and root water uptake (RWU) strategy. In this zone, transpiration is progressively more sensitive to the groundwater level as roots become shallower. The impact of drought on corn (Zea mays L.) lessens and corn becomes less reliant on compensated RWU capabilities as roots extend deeper. Simulations indicated that the use of the compensated RWU approach results in NPP increases of 38.1 (3.81%), 30.8 (2.74%), and 6.4 (0.55%) g C m-2 yr-1 during the driest years (i.e., when growing season precipitation is below the 30th percentile of the long-term observations) for shallow, intermediate, and deep RLDs, respectively. Moreover, shallow groundwater supported RWU, and corn with a shallow RLD benefited the most from shallow groundwater, with an increase in annual transpiration of 230 mm. Our findings underscore the importance of incorporating compensatory RWU and selecting an appropriate and representative RLD for contrasting vegetation types in ecosystem models to simulate a more realistic plant response to variable climate and groundwater depth conditions. VL - 16 UR - http://dx.doi.org/10.2136/vzj2017.06.0118 ER - TY - JOUR T1 - The Influence of Legacy P on Lake Water Quality in a Midwestern Agricultural Watershed JF - Ecosystems Y1 - 2017 A1 - Motew, Melissa A1 - Chen, Xi A1 - Booth, Eric G. A1 - Carpenter, Stephen R. A1 - Pinkas, Pavel A1 - Zipper, Samuel C. A1 - Loheide, Steven P. A1 - Donner, Simon D. A1 - Tsuruta, Kai A1 - Vadas, Peter A. A1 - Kucharik, Christopher J. AB - Decades of fertilizer and manure applications have led to a buildup of phosphorus (P) in agricultural soils and sediments, commonly referred to as legacy P. Legacy P can provide a long-term source of P to surface waters where it causes eutrophication. Using a suite of numerical models, we investigated the influence of legacy P on water quality in the Yahara Watershed of southern Wisconsin, USA. The suite included Agro-IBIS, a terrestrial ecosystem model; THMB, a hydrologic and nutrient routing model; and the Yahara Water Quality Model which estimates water quality indicators in the Yahara chain of lakes. Using five alternative scenarios of antecedent P storage (legacy P) in soils and channels under historical climate conditions, we simulated outcomes of P yield from the landscape, lake P loading, and three lake water quality indicators. Legacy P had a significant effect on lake loads and water quality. Across the five scenarios for Lake Mendota, the largest and most upstream lake, average P yield (kg ha−1) varied by −41 to +22%, P load (kg y−1) by −35 to +14%, summer total P (TP) concentration (mg l−1) by −25 to +12%, Secchi depth (m) by −7 to +3%, and the probability of hypereutrophy by −67 to +34%, relative to baseline conditions. The minimum storage scenario showed that a 35% reduction in present-day loads to Lake Mendota corresponded with a 25% reduction in summer TP and smaller reductions in the downstream lakes. Water quality was more vulnerable to heavy rainfall events at higher amounts of P storage and less so at lower amounts. Increases in heavy precipitation are expected with climate change; therefore, water quality could be protected by decreasing P reserves. SN - 1435-0629 UR - http://dx.doi.org/10.1007/s10021-017-0125-0 JO - Ecosystems ER - TY - JOUR T1 - Public access to spatial data on private-land conservation JF - Ecology and Society Y1 - 2017 A1 - Rissman, Adena R. A1 - Owley, Jessica A1 - L'Roe, Andrew W. A1 - Morris, Amy Wilson A1 - Wardropper, Chloe B. KW - conservation easements KW - cost share KW - Environmental governance KW - Geographic Information Systems KW - land trusts KW - privacy KW - private-land conservation KW - tax incentive KW - transparency AB - Information is critical for environmental governance. The rise of digital mapping has the potential to advance private-land conservation by assisting with conservation planning, monitoring, evaluation, and accountability. However, privacy concerns from private landowners and the capacity of conservation entities can influence efforts to track spatial data. We examine public access to geospatial data on conserved private lands and the reasons data are available or unavailable. We conduct a qualitative comparative case study based on analysis of maps, documents, and interviews. We compare four conservation programs involving different conservation tools: conservation easements (the growing but incomplete National Conservation Easement Database), regulatory mitigation (gaps in tracking U.S. Fish and Wildlife Service’s endangered species habitat mitigation), contract payments (lack of spatial data on U.S. Department of Agriculture’s Conservation Reserve Program due to Farm Bill restrictions), and property-tax incentives (online mapping of Wisconsin’s managed forest tax program). These cases illuminate the capacity and privacy reasons for current incomplete or inaccessible spatial data and the politics of mapping private land. If geospatial data are to contribute fully to planning, evaluation, and accountability, we recommend improving information system capacity, enhancing learning networks, and reducing legal and administrative barriers to information access, while balancing the right to information and the right to privacy. VL - 22 UR - https://www.ecologyandsociety.org/vol22/iss2/art24/ IS - 2 ER - TY - JOUR T1 - Urban heat island-induced increases in evapotranspirative demand JF - Geophysical Research Letters Y1 - 2017 A1 - Zipper, Samuel C. A1 - Schatz, Jason A1 - Kucharik, Christopher J. A1 - Loheide, Steven P. KW - ecohydrology KW - plant water use KW - reference evapotranspiration KW - urban climatology KW - urban ecology KW - urban heat island KW - Urban systems KW - Water supply AB - Although the importance of vegetation in mitigating the urban heat island (UHI) is known, the impacts of UHI-induced changes in micrometeorological conditions on vegetation are not well understood. Here we show that plant water requirements are significantly higher in urban areas compared to rural areas surrounding Madison, WI, driven by increased air temperature with minimal effects of decreased air moisture content. Local increases in impervious cover are strongly associated with increased evapotranspirative demand in a consistent manner across years, with most increases caused by elevated temperatures during the growing season rather than changes in changes in growing season length. Potential evapotranspiration is up to 10% higher due to the UHI, potentially mitigating changes to the water and energy balances caused by urbanization. Our results indicate that local-scale land cover decisions (increases in impervious cover) can significantly impact evapotranspirative demand, with likely implications for water and carbon cycling in urban ecosystems. SN - 1944-8007 UR - http://dx.doi.org/10.1002/2016GL072190 ER - TY - JOUR T1 - Urban heat island impacts on plant phenology: intra-urban variability and response to land cover JF - Environmental Research Letters Y1 - 2016 A1 - Samuel C Zipper A1 - Jason Schatz A1 - Aditya Singh A1 - Christopher J Kucharik A1 - Philip A Townsend A1 - Steven P Loheide KW - land surface phenology KW - remote sensing KW - sensor network KW - urban climate KW - urban ecology KW - urban heat island KW - vegetation phenology AB - Despite documented intra-urban heterogeneity in the urban heat island (UHI) effect, little is knownabout spatial or temporal variability in plant response to the UHI. Using an automated temperaturesensor network in conjunction with Landsat-derived remotely sensed estimates of start/end of thegrowing season, we investigate the impacts of the UHI on plant phenology in the city of Madison WI(USA) for the 2012–2014 growing seasons. Median urban growing season length (GSL) estimated fromtemperature sensors is ∼5 d longer than surrounding rural areas, and UHI impacts on GSL arerelatively consistent from year-to-year. Parks within urban areas experience a subdued expression ofGSL lengthening resulting from interactions between the UHI and a park cool island effect. Acrossall growing seasons, impervious cover in the area surrounding each temperature sensor explains >50%of observed variability in phenology. Comparisons between long-term estimates of annual meanphenological timing, derived from remote sensing, and temperature-based estimates of individualgrowing seasons show no relationship at the individual sensor level. The magnitude of disagreementbetween temperature-based and remotely sensed phenology is a function of impervious and grass coversurrounding the sensor, suggesting that realized GSL is controlled by both local land cover andmicrometeorological conditions. VL - 11 SN - 1748-9326 UR - http://stacks.iop.org/1748-9326/11/i=5/a=054023 IS - 5 ER - TY - JOUR T1 - Plausible futures of a social-ecological system: Yahara watershed, Wisconsin, USA JF - Ecology and Society Y1 - 2015 A1 - Carpenter, Stephen R. A1 - Booth, Eric G. A1 - Gillon, Sean A1 - Kucharik, Christopher J. A1 - Loheide, Steven A1 - Mase, Amber S. A1 - Motew, Melissa A1 - Qiu, Jiangxiao A1 - Rissman, Adena R. A1 - Seifert, Jenny A1 - Soylu, Evren A1 - Turner, Monica A1 - Wardropper, Chloe B. KW - alternative futures KW - climate KW - ecosystem services KW - eutrophication KW - governance KW - lakes KW - land-use change KW - phosphorus KW - scenarios AB - Agricultural watersheds are affected by changes in climate, land use, agricultural practices, and human demand for energy, food, and water resources. In this context, we analyzed the agricultural, urbanizing Yahara watershed (size: 1345 km², population: 372,000) to assess its responses to multiple changing drivers. We measured recent trends in land use/cover and water quality of the watershed, spatial patterns of 10 ecosystem services, and spatial patterns and nestedness of governance. We developed scenarios for the future of the Yahara watershed by integrating trends and events from the global scenarios literature, perspectives of stakeholders, and models of biophysical drivers and ecosystem services. Four qualitative scenarios were created to explore plausible trajectories to the year 2070 in the watershed’s social-ecological system under different regimes: no action on environmental trends, accelerated technological development, strong intervention by government, and shifting values toward sustainability. Quantitative time-series for 2010–2070 were developed for weather and land use/cover during each scenario as inputs to model changes in ecosystem services. Ultimately, our goal is to understand how changes in the social-ecological system of the Yahara watershed, including management of land and water resources, can build or impair resilience to shifting drivers, including climate. VL - 20 UR - http://www.ecologyandsociety.org/vol20/iss2/art10/ IS - 2 JO - Ecology and Society ER - TY - JOUR T1 - Untangling the effects of shallow groundwater and soil texture as drivers of subfield-scale yield variability JF - Water Resources Research Y1 - 2015 A1 - Zipper, Samuel C. A1 - Soylu, Mehmet Evren A1 - Booth, Eric G. A1 - Loheide, Steven P. KW - 0402 Agricultural systems KW - 0486 Soils/pedology KW - 1813 Eco-hydrology KW - 1829 Groundwater hydrology KW - agroecosystem modeling KW - AgroIBIS-VSF KW - Hydrus-1D KW - Precision agriculture KW - soil-plant-atmosphere continuum KW - water table AB - Water table depth (WTD), soil texture, and growing season weather conditions all play critical roles in determining agricultural yield; however, the interactions among these three variables have never been explored in a systematic way. Using a combination of field observations and biophysical modeling, we answer two questions: (1) under what conditions can a shallow water table provide a groundwater yield subsidy and/or penalty to corn production?; and, (2) how do soil texture and growing season weather conditions influence the relationship between WTD and corn yield? Subfield-scale yield patterns during a dry (2012) and wet (2013) growing season are used to identify sensitivity to weather. Areas of the field that are negatively impacted by wet growing seasons have the shallowest observed WTD (< 1 m), while areas with consistently strong yield have intermediate WTD (1-3 m). Parts of the field that perform consistently poorly are characterized by deep WTD (> 3 m) and coarse soil textures. Modeling results find that beneficial impacts of shallow groundwater are more common than negative impacts under the conditions studied, and that the optimum WTD is shallower in coarser soils. While groundwater yield subsidies have a higher frequency and magnitude in coarse-grained soils, the optimum WTD responds to growing season weather at a relatively constant rate across soil types. We conclude that soil texture defines a baseline upon which WTD and weather interact to determine overall yield. Our work has implications for water resource management, climate/land use change impacts on agricultural production, and precision agriculture. This article is protected by copyright. All rights reserved. SN - 1944-7973 UR - http://dx.doi.org/10.1002/2015WR017522 ER - TY - JOUR T1 - Extreme daily loads: role in annual phosphorus input to a north temperate lake JF - Aquatic Sciences Y1 - 2014 A1 - Carpenter, Stephen R A1 - Booth, Eric G A1 - Kucharik, Christopher J A1 - Lathrop, Richard C KW - Daily load extremes KW - Lake KW - Phosphorus load KW - Water quality AB - Changes in fertilizer use, manure management or precipitation may alter the frequency of episodes of high nutrient runoff and thereby affect annual nutrient loads and total nutrient concentrations of lakes. We developed an empirical, stochastic model for daily P loads and used the model to project annual P loads and summer total P concentrations in Lake Mendota, Wisconsin, USA. Daily P loads (8,250 daily observations) were fit closely by a three-part gamma distribution composed of days with low, intermediate, and high P loads. High P load days happen when heavy rains or snowmelt occur on soil with abundant P, often as a result of manure or inorganic fertilizer application. In Lake Mendota, on average 29 days per year accounted for 74 % of the annual load. Simulations showed that median annual P loads increased linearly with the frequency of high P load days. However, the upper quantiles of the annual P load distribution increased more steeply than the median. Increases in the number of high P load days per year also increased summer concentrations of P in the lake. Thus increases in the frequency of high P load days due to larger precipitation events or increased application of fertilizers and manure may worsen widespread problems caused by P pollution of lakes in this agricultural watershed. SN - 1015-1621 UR - http://dx.doi.org/10.1007/s00027-014-0364-5 JO - Aquat Sci ER - TY - JOUR T1 - Influence of groundwater on plant water use and productivity: Development of an integrated ecosystem - Variably saturated soil water flow model JF - Agricultural and Forest Meteorology Y1 - 2014 A1 - Soylu, M. E. A1 - Kucharik, C. J. A1 - Loheide, S. P. AB - Plant physiology influences the energy and water balance of the soil-plant-atmosphere continuum. However, impacts of soil water dynamics on plants in shallow groundwater environments are not completely understood, partially due to the limited ability of current models to simulate groundwater vegetation interactions. In this study, we analyzed the influence of groundwater-induced soil temperature change on plant phenology, and the impact of variable depth to the water table on the net primary productivity (NPP), evapotranspiration and stomatal response, by integrating an advanced dynamic agroecosystem model (Agro-IBIS) and a variably saturated soil water flow model (Hydrus-1D) into a single framework. The model is first evaluated using field observations of soil moisture and temperature as well as annual NPP and weekly LAI measurements collected from three replicated maize plots at the Arlington Agricultural Research Station near Arlington, Wisconsin, USA. Comparisons showed reasonable agreement for each dataset without site-specific prior calibration. We then simulated the influence of groundwater on plant physiological responses as well as the energy, carbon, and water balance at the land surface. The model sensitivity analyses indicated that physiological functions of plants are sensitive to water table depth, and the aridity of a particular production site. For example, shallow groundwater limits water stress during dry years, helping to mitigate decreased NPP associated with water deficits. However, if the water table is persistently too close to the surface during the growing season, photosynthesis is negatively affected through oxygen stress on roots regardless of the aridity. To further explore factors influencing plant physiology other than oxygen stress, we designed simulations without oxygen stress effects. Results showed that under shallow groundwater conditions: (1) higher leaf level relative humidity causes higher water use efficiency because of a lower vapor pressure deficit between the leaf and atmosphere: (2) due to delayed corn plant emergence caused by cooler springtime soil temperatures reduces NPP. Our results suggest that models designed to more mechanistically simulate groundwater vegetation interactions may lead to a more realistic representation of feedbacks between plant phenology, soil moisture, temperature, anoxia, NPP and ET. However, until critical data are collected to assess simulated feedbacks and advance our understanding of groundwater vegetation interactions, model confidence will likely remain somewhat limited. (C) 2014 Elsevier B.V. All rights reserved. VL - 189 UR - http://dx.doi.org/10.1016/j.agrformet.2014.01.019 ER - TY - JOUR T1 - Phosphorus loading, transport and concentrations in a lake chain: a probabilistic model to compare management options JF - Aquatic Sciences Y1 - 2014 A1 - Carpenter, S. R. A1 - Lathrop, R. C. AB - Phosphorus (P) loading, exports and concentrations of the four lakes of the Yahara chain (Wisconsin, USA) were compared under four load-reduction plans using a model calibrated with 29-33 years of annual data. P mitigation goals must balance reductions in P concentrations in the four lakes and the export from the lake chain to downstream waters. Lake Mendota, the uppermost lake, is most responsive to P load reductions, and benefits diminish downstream. Nonetheless, the greatest reductions in export from the lake chain to downstream waters derive from P load reductions to lakes lower in the chain. The effective grazer Daphnia pulicaria causes large improvements in water quality. Management to maintain populations of D. pulicaria has substantial benefits that augment those from reductions in P loading. Model projections show high variability in water quality and exports under all load-reduction plans. This variability is driven by inter-annual variation in runoff. Thus lake managers and the public should expect ongoing year-to-year variability in water quality, even though P load mitigation will improve water quality on average. Because of high variability from year to year, ongoing monitoring is essential to assess the effects of management of this chain of lakes. VL - 76 SN - 1015-1621 UR - http://dx.doi.org/10.1007/s00027-013-0324-5 IS - 1 ER - TY - JOUR T1 - Water quality implications from three decades of phosphorus loads and trophic dynamics in the Yahara chain of lakes JF - Inland Waters Y1 - 2014 A1 - Lathrop, R. C. A1 - Carpenter, S. R. AB - Trophic responses to phosphorus (P) loads spanning 29-33 years were assessed for the eutrophic Yahara chain of lakes: Mendota (area = 39.6 km(2), mean depth = 12.7 m, flushing rate = 0.23 yr(-1)); Monona (13.7 km(2), 8.3 m, 1.3 yr(-1)); Waubesa (8.5 km(2), 4.7 m, 4.3 yr(-1)); and Kegonsa (13.0 km(2), 5.1 m, 3.0 yr(-1)). During extended drought periods with low P loads, summer (Jul-Aug) total P (TP) concentrations declined substantially in all 4 lakes, with Mendota achieving mesotrophic conditions (<0.024 mg L-1). In years when P loads were high due to major runoff events, summer TP in the lakes was high (especially in shallower Waubesa and Kegonsa); in some summers dissolved inorganic P was elevated, indicating algae growth was not P limited. Summer TP returned to normal levels following both low and high load years, signifying the lakes were responsive to P load changes. The proportion of P input loads passed via a lake's outlet to the next lake downstream increased as flushing rates increased. Because Monona, Waubesa, and Kegonsa received 60, 83, and 76% of their surface water P load from the respective upstream lake's outlet, reducing P loads in Mendota's large watershed was predicted to produce significant water quality benefits downstream. Modeling indicated a significant grazing effect of Daphnia on summer TP and Secchi transparency readings for Mendota and Monona. Finally, using drought loads as targets, our study established P loading reductions needed to improve water quality in all 4 Yahara lakes. VL - 4 UR - http://dx.doi.org/10.5268/iw-4.1.680 IS - 1 ER - TY - JOUR T1 - What is the influence on water quality in temperate eutrophic lakes of a reduction of planktivorous and benthivorous fish? A systematic review protocol JF - Environmental Evidence Y1 - 2013 A1 - Bernes, C. A1 - Carpenter, S. R. A1 - Gardmark, A. A1 - Larsson, P. A1 - Persson, L. A1 - Skov, C. A1 - Van Donk, E. AB - BACKGROUND:In lakes that have become eutrophic due to sewage discharges or nutrient runoff from land, problems such as algal blooms and oxygen deficiency often persist even when nutrient supplies have been reduced. One reason is that phosphorus stored in the sediments can exchange with the water. There are indications that the high abundance of phytoplankton, turbid water and lack of submerged vegetation seen in many eutrophic lakes may represent a semi-stable state. For that reason, a shift back to more natural clear-water conditions could be difficult to achieve.In some cases, though, temporary mitigation of eutrophication-related problems has been accomplished through biomanipulation: stocks of zooplanktivorous fish have been reduced by intensive fishing, leading to increased populations of phytoplankton-feeding zooplankton. Moreover, reduction of benthivorous fish may result in lower phosphorus fluxes from the sediments. An alternative to reducing the dominance of planktivores and benthivores by fishing is to stock lakes with piscivorous fish. These two approaches have often been used in combination.The implementation of the EU Water Framework Directive has recently led to more stringent demands for measures against eutrophication, and a systematic review could clarify whether biomanipulation is efficient as a measure of that kind.METHODS:The review will examine primary field studies of how large-scale biomanipulation has affected water quality and community structure in eutrophic lakes or reservoirs in temperate regions. Such studies can be based on comparison between conditions before and after manipulation, on comparison between treated and non-treated water bodies, or both. Relevant outcomes include Secchi depth, concentrations of oxygen, nutrients, suspended solids and chlorophyll, abundance and composition of phytoplankton, zooplankton and fish, and coverage of submerged macrophytes. VL - 2 UR - http://www.environmentalevidencejournal.org/content/2/1/9 IS - 1 ER - TY - JOUR T1 - General Resilience to Cope with Extreme Events JF - Sustainability Y1 - 2012 A1 - Carpenter, S. R. A1 - Arrow, K. J. A1 - Barrett, S. A1 - Biggs, R. A1 - Brock, W. A. A1 - Crepin, A. S. A1 - Engstrom, G. A1 - Folke, C. A1 - Hughes, T. P. A1 - Kautsky, N. A1 - Li, C. Z. A1 - McCarney, G. A1 - Meng, K. A1 - Maler, K. G. A1 - Polasky, S. A1 - Scheffer, M. A1 - Shogren, J. A1 - Sterner, T. A1 - Vincent, J. R. A1 - Walker, B. A1 - Xepapadeas, A. A1 - de Zeeuw, A. AB - Resilience to specified kinds of disasters is an active area of research and practice. However, rare or unprecedented disturbances that are unusually intense or extensive require a more broad-spectrum type of resilience. General resilience is the capacity of social-ecological systems to adapt or transform in response to unfamiliar, unexpected and extreme shocks. Conditions that enable general resilience include diversity, modularity, openness, reserves, feedbacks, nestedness, monitoring, leadership, and trust. Processes for building general resilience are an emerging and crucially important area of research. VL - 4 SN - 2071-1050 UR - http://dx.doi.org/10.3390/su4123248 IS - 12 ER -