@article {185,
	title = {Comparing the effects of climate and land use on surface water quality using future watershed scenarios},
	journal = {Science of the Total Environment},
	volume = {693},
	year = {2019},
	month = {2019/11/25/},
	pages = {133484},
	abstract = {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{\textendash}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.},
	keywords = {climate, land use, Manure, phosphorus, Surface water quality, Watershed},
	isbn = {0048-9697},
	doi = {10.1016/j.scitotenv.2019.07.290},
	url = {http://www.sciencedirect.com/science/article/pii/S0048969719334047},
	author = {Motew, Melissa and Chen, Xi and Carpenter, Stephen R. and Booth, Eric G. and Seifert, Jenny and Qiu, Jiangxiao and Loheide, Steven P. and Turner, Monica G. and Zipper, Samuel C. and Kucharik, Christopher J.}
}
@article {184,
	title = {Management of minimum lake levels and impacts on flood mitigation: A case study of the Yahara Watershed, Wisconsin, USA},
	journal = {Journal of Hydrology},
	volume = {577},
	year = {2019},
	month = {2019/10/01/},
	abstract = {Lake level regulation is commonly used to manage water resources and mitigate flood risk in watersheds with linked river{\textendash}lake systems. In this study, we first assess exposure, in terms of both population and land area, to flooding impacts in the Yahara Watershed{\textquoteright}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{\textendash}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.},
	keywords = {ecosystem services, Flood exposure assessment, Hydrologic model, Lake level management},
	isbn = {0022-1694},
	doi = {10.1016/j.jhydrol.2019.123920},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169419306407},
	author = {Chen, Xi and Motew, Melissa M. and Booth, Eric G. and Zipper, Samuel C. and Loheide, Steven P. and Kucharik, Christopher J.}
}
@article {179,
	title = {Continuous separation of land use and climate effects on the past and future water balance},
	journal = {Journal of Hydrology},
	volume = {565},
	year = {2018},
	month = {2018/10/01/},
	pages = {106-122},
	abstract = {Understanding the combined and separate effects of climate and land use change on the water cycle is necessary to mitigate negative impacts. However, existing methodologies typically divide data into discrete (before and after) periods, implicitly representing climate and land use as step changes when in reality these changes are often gradual. Here, we introduce a new regression-based methodological framework designed to separate climate and land use effects on any hydrological flux of interest continuously through time, and estimate uncertainty in the contribution of these two drivers. We present two applications in the Yahara River Watershed (Wisconsin, USA) demonstrating how our approach can be used to understand synergistic or antagonistic relationships between land use and climate in either the past or the future: (1) historical streamflow, baseflow, and quickflow in an urbanizing subwatershed; and (2) simulated future evapotranspiration, drainage, and direct runoff from a suite of contrasting climate and land use scenarios for the entire watershed. In the historical analysis, we show that \~{}60\% of recent streamflow changes can be attributed to climate, with approximately equal contributions from quickflow and baseflow. However, our continuous method reveals that baseflow is significantly increasing through time, primarily due to land use change and potentially influenced by long-term increases in groundwater storage. In the simulation of future changes, we show that all components of the future water balance will respond more strongly to changes in climate than land use, with the largest potential land use effects on drainage. These results indicate that diverse land use change trajectories may counteract each other while the effects of climate are more homogeneous at watershed scales. Therefore, management opportunities to counteract climate change effects will likely be more effective at smaller spatial scales, where land use trajectories are unidirectional.},
	keywords = {Baseflow, Climate change, Evapotranspiration, Land use change, Streamflow, Urbanization},
	doi = {10.1016/j.jhydrol.2018.08.022},
	url = {http://www.sciencedirect.com/science/article/pii/S0022169418306188},
	author = {Zipper, Samuel C. and Motew, Melissa and Booth, Eric G. and Chen, Xi and Qiu, Jiangxiao and Kucharik, Christopher J. and Carpenter, Stephen R. and Loheide II, Steven P.}
}
@article {178,
	title = {The synergistic effect of manure supply and extreme precipitation on surface water quality},
	journal = {Environmental Research Letters},
	year = {2018},
	month = {2018},
	abstract = {Over-enrichment of phosphorus (P) in agroecosystems contributes to eutrophication of surface waters. In the Midwest U.S. and elsewhere, climate change is increasing the frequency of high-intensity precipitation events, which can serve as a primary conduit of P transport. Despite uncertainty in their estimates, process-based watershed models are important tools that help characterize watershed hydrology and biogeochemistry and scale up important mechanisms affecting water quality. Using one such model developed for an agricultural watershed in Wisconsin, we conducted a 2x2 factorial experiment to test the effects of (high/low) terrestrial P supply (PSUP) and (high/low) precipitation intensity (PREC) on surface water quality. Sixty-year simulations were conducted for each of the four runs, with annual results obtained for watershed average P yield and concentration at the field scale (220m x 220m grid cells), P load and concentration at the stream scale, and summertime total P concentration (TP) in Lake Mendota. ANOVA results were generated for the 2x2 factorial design, with PSUP and PREC treated as categorical variables. The results showed a significant, positive interaction (p\&lt;0.01) between the two drivers for dissolved P concentration at the field and stream scales, and total P concentration at the field, stream, and lake scales. The synergy in dissolved P was linked to nonlinear dependencies between P stored in manure and the daily runoff to rainfall ratio. The synergistic response of dissolved P loss may have important ecological consequences because dissolved P is highly bioavailable. Overall, the results suggest that high levels of terrestrial P supplied as manure can exacerbate water quality problems in the future as the frequency of high-intensity rainfall events increases with a changing climate. Conversely, lowering terrestrial manure P supply may help improve the resilience of surface water quality to extreme events.},
	isbn = {1748-9326},
	doi = {10.1088/1748-9326/aaade6},
	url = {http://iopscience.iop.org/10.1088/1748-9326/aaade6},
	author = {Melissa Motew and Eric G. Booth and Stephen R. Carpenter and Xi Chen and Christopher J. Kucharik}
}
@article {176,
	title = {Extreme precipitation and phosphorus loads from two agricultural watersheds},
	journal = {Limnology and Oceanography},
	year = {2017},
	pages = {n/a - n/a},
	abstract = {Phosphorus runoff from agricultural land is a major cause of eutrophication in lakes and reservoirs. Frequency and intensity of extreme precipitation events are increasing in agricultural regions of the Upper Midwestern U.S., and these increases are projected to continue as climate warms. We quantified the linkage between extreme daily precipitation and extreme daily discharge, phosphorus (P) load, and P concentration for Pheasant Branch and the Yahara River, two tributaries of Lake Mendota, Wisconsin, U.S.A. using the generalized Pareto distribution. Although precipitation extremes have increased since 1940, over the shorter period of stream monitoring (1994{\textendash}2015 for Pheasant Branch and 1991{\textendash}2015 for Yahara) there is no significant trend in extreme precipitation. Nonetheless a disproportionate number of extreme precipitation events (for example seven of the 11 largest 24-h events since 1901) occurred during the period of stream monitoring. Daily precipitation extremes were associated with extremes in daily discharge and P load. P load return levels increased steeply and almost linearly with precipitation on log-log axes. The trend toward more frequent and intense precipitation extremes will increase P loading and intensify the eutrophication of the lake, unless the excessive P enrichment of the watershed is reversed.},
	isbn = {1939-5590},
	doi = {10.1002/lno.10767},
	url = {http://dx.doi.org/10.1002/lno.10767},
	author = {Carpenter, Stephen R. and Booth, Eric G. and Kucharik, Christopher J.}
}
@article {164,
	title = {The Influence of Legacy P on Lake Water Quality in a Midwestern Agricultural Watershed},
	journal = {Ecosystems},
	year = {2017},
	month = {2017//},
	pages = {1 - 15},
	abstract = {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.},
	isbn = {1435-0629},
	doi = {10.1007/s10021-017-0125-0},
	url = {http://dx.doi.org/10.1007/s10021-017-0125-0},
	author = {Motew, Melissa and Chen, Xi and Booth, Eric G. and Carpenter, Stephen R. and Pinkas, Pavel and Zipper, Samuel C. and Loheide, Steven P. and Donner, Simon D. and Tsuruta, Kai and Vadas, Peter A. and Kucharik, Christopher J.}
}
@article {127,
	title = {Biodiversity and ecosystem services require IPBES to take novel approach to scenarios},
	journal = {Sustainability Science},
	year = {2016},
	month = {2016},
	pages = {1 - 5},
	abstract = {What does the future hold for the world{\textquoteright}s ecosystems and benefits that people obtain from them? While the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) has identified the development of scenarios as a key to helping decision makers identify potential impacts of different policy options, it currently lacks a long-term scenario strategy. IPBES will decide how it will approach scenarios at its plenary meeting on 22{\textendash}28 February 2016, in Kuala Lumpur. IPBES now needs to decide whether it should create new scenarios that better explore ecosystem services and biodiversity dynamics. For IPBES to capture the social-ecological dynamics of biodiversity and ecosystem services, it is essential to engage with the great diversity of local contexts, while also including the global tele-coupling among local places. We present and compare three alternative scenario strategies that IPBES could use and then suggest a bottom-up, cross-scale scenario strategy to improve the policy relevance of future IPBES assessments. We propose five concrete steps as part of an effective, long term scenario development process for IPBES in cooperation with the scientific community.},
	isbn = {1862-4057},
	doi = {10.1007/s11625-016-0354-8},
	url = {http://dx.doi.org/10.1007/s11625-016-0354-8},
	author = {Kok, Marcel T. J. and Kok, Kasper and Peterson, Garry D. and Hill, Rosemary and Agard, John and Carpenter, Stephen R.}
}
@article {147,
	title = {From qualitative to quantitative environmental scenarios: Translating storylines into biophysical modeling inputs at the watershed scale},
	journal = {Environmental Modelling \& Software},
	volume = {85},
	year = {2016},
	pages = {80 - 97},
	abstract = {Scenarios are increasingly used for envisioning future social-ecological changes and consequences for human well-being. One approach integrates qualitative storylines and biophysical models to explore potential futures quantitatively and maximize public engagement. However, this integration process is challenging and sometimes oversimplified. Using the Yahara Watershed (Wisconsin, USA) as a case study, we present a transparent and reproducible roadmap to develop spatiotemporally explicit biophysical inputs [climate, land use/cover (LULC), and nutrients] that are consistent with scenario narratives and can be linked to a process-based biophysical modeling suite to simulate long-term dynamics of a watershed and a range of ecosystem services. Our transferrable approach produces daily weather inputs by combining climate model projections and a stochastic weather generator, annual narrative-based watershed-scale LULC distributed spatially using transition rules, and annual manure and fertilizer (nitrogen and phosphorus) inputs based on current farm and livestock data that are consistent with each scenario narrative.},
	keywords = {Biophysical modeling, Climate change, Land use change, scenarios, Social-ecological systems, Watershed},
	isbn = {1364-8152},
	doi = {10.1016/j.envsoft.2016.08.008},
	url = {http://www.sciencedirect.com/science/article/pii/S1364815216304935},
	author = {Booth, Eric G. and Qiu, Jiangxiao and Carpenter, Stephen R. and Schatz, Jason and Chen, Xi and Kucharik, Christopher J. and Loheide II, Steven P. and Motew, Melissa M. and Seifert, Jenny M. and Turner, Monica G.}
}
@article {134,
	title = {Invasive species triggers a massive loss of ecosystem services through a trophic cascade},
	journal = {Proceedings of the National Academy of Sciences},
	year = {2016},
	month = {2016/03/21},
	abstract = {Despite growing recognition of the importance of ecosystem services and the economic and ecological harm caused by invasive species, linkages between invasions, changes in ecosystem functioning, and in turn, provisioning of ecosystem services remain poorly documented and poorly understood. We evaluate the economic impacts of an invasion that cascaded through a food web to cause substantial declines in water clarity, a valued ecosystem service. The predatory zooplankton, the spiny water flea (Bythotrephes longimanus), invaded the Laurentian Great Lakes in the 1980s and has subsequently undergone secondary spread to inland lakes, including Lake Mendota (Wisconsin), in 2009. In Lake Mendota, Bythotrephes has reached unparalleled densities compared with in other lakes, decreasing biomass of the grazer Daphnia pulicaria and causing a decline in water clarity of nearly 1 m. Time series modeling revealed that the loss in water clarity, valued at US$140 million (US$640 per household), could be reversed by a 71\% reduction in phosphorus loading. A phosphorus reduction of this magnitude is estimated to cost between US$86.5 million and US$163 million (US$430{\textendash}US$810 per household). Estimates of the economic effects of Great Lakes invasive species may increase considerably if cases of secondary invasions into inland lakes, such as Lake Mendota, are included. Furthermore, such extreme cases of economic damages call for increased investment in the prevention and control of invasive species to better maximize the economic benefits of such programs. Our results highlight the need to more fully incorporate ecosystem services into our analysis of invasive species impacts, management, and public policy.},
	doi = {10.1073/pnas.1600366113},
	url = {http://www.pnas.org/content/early/2016/03/16/1600366113.abstract},
	author = {Walsh, Jake R. and Carpenter, Stephen R. and Vander Zanden, M. Jake}
}
@article {135,
	title = {Local perspectives and global archetypes in scenario development},
	journal = {Ecology and Society},
	volume = {21},
	year = {2016},
	month = {2016},
	abstract = {Contrasting social-ecological scenarios can help stakeholders envision potential futures and navigate change and uncertainty. Scenario developers integrate stakeholder perceptions into storylines to increase scenario relevance and plausibility while relying on archetypes of change from scenario literature to enrich narratives. This research examines the contributions of local perspectives and global archetypes to scenario development through a case study of a regional scenario project, Yahara 2070, in Wisconsin, USA. Interviews with 50 Yahara watershed stakeholders and 5 members of the project{\textquoteright}s scenario development team were examined to compare themes from scenario archetypes with local perspectives on how change is expected to occur. We next examined how these two sources of inspiration for trajectories of change were used in the development of the Yahara 2070 scenarios. Both global archetypes and local stakeholders emphasized social values, market forces, and policy reform as influences in determining the future, which were reflected in Yahara 2070. However, stakeholders were less likely to mention institutional breakdown, an important theme from the global scenarios literature that was included in Yahara 2070. This research offers a new approach to analyzing similarities and differences between scenarios\&$\#$8217; narratives and local perspectives. Scenario development may involve tensions between the goals of reflecting stakeholder views and including narratives from the global scenarios literature that may be useful for  creating divergent model trajectories and addressing dramatic change into the future. To improve scenario development, scenario projects should document the development process in academic and nonacademic venues, explicitly highlighting sources and constraints in storyline development.},
	keywords = {scenario archetypes, scenario development, social and environmental change, stakeholder perspectives, watershed futures},
	doi = {10.5751/ES-08384-210212},
	url = {http://www.ecologyandsociety.org/vol21/iss2/art12/},
	author = {Wardropper, Chloe B. and Gillon, Sean and Mase, Amber S. and McKinney, Emily A. and Carpenter, Stephen R. and Rissman, Adena R.}
}
@article {158,
	title = {Reducing Phosphorus to Curb Lake Eutrophication is a Success},
	journal = {Environmental Science \& Technology},
	volume = {50},
	year = {2016},
	month = {2016/09/06},
	pages = {8923 - 8929},
	abstract = {As human populations increase and land-use intensifies, toxic and unsightly nuisance blooms of algae are becoming larger and more frequent in freshwater lakes. In most cases, the blooms are predominantly blue-green algae (Cyanobacteria), which are favored by low ratios of nitrogen to phosphorus. In the past half century, aquatic scientists have devoted much effort to understanding the causes of such blooms and how they can be prevented or reduced. Here we review the evidence, finding that numerous long-term studies of lake ecosystems in Europe and North America show that controlling algal blooms and other symptoms of eutrophication depends on reducing inputs of a single nutrient: phosphorus. In contrast, small-scale experiments of short duration, where nutrients are added rather than removed, often give spurious and confusing results that bear little relevance to solving the problem of cyanobacteria blooms in lakes.As human populations increase and land-use intensifies, toxic and unsightly nuisance blooms of algae are becoming larger and more frequent in freshwater lakes. In most cases, the blooms are predominantly blue-green algae (Cyanobacteria), which are favored by low ratios of nitrogen to phosphorus. In the past half century, aquatic scientists have devoted much effort to understanding the causes of such blooms and how they can be prevented or reduced. Here we review the evidence, finding that numerous long-term studies of lake ecosystems in Europe and North America show that controlling algal blooms and other symptoms of eutrophication depends on reducing inputs of a single nutrient: phosphorus. In contrast, small-scale experiments of short duration, where nutrients are added rather than removed, often give spurious and confusing results that bear little relevance to solving the problem of cyanobacteria blooms in lakes.},
	isbn = {0013-936X},
	doi = {10.1021/acs.est.6b02204},
	url = {http://dx.doi.org/10.1021/acs.est.6b02204},
	author = {Schindler, David W. and Carpenter, Stephen R. and Chapra, Steven C. and Hecky, Robert E. and Orihel, Diane M.}
}
@article {93,
	title = {Creating a safe operating space for iconic ecosystems},
	journal = {Science},
	volume = {347},
	year = {2015},
	month = {2015/03/20},
	pages = {1317 - 1319},
	doi = {10.1126/science.aaa3769},
	url = {http://www.sciencemag.org/content/347/6228/1317.short},
	author = {Scheffer, M. and Barrett, S. and Carpenter, S. R. and Folke, C. and Green, A. J. and Holmgren, M. and Hughes, T. P. and Kosten, S. and van de Leemput, I. A. and Nepstad, D. C. and van Nes, E. H. and Peeters, E. T. H. M. and Walker, B.}
}
@article {91,
	title = {Fragmented water quality governance: Constraints to spatial targeting for nutrient reduction in a Midwestern USA watershed},
	journal = {Landscape and Urban Planning},
	volume = {137},
	year = {2015},
	pages = {64 - 75},
	abstract = {Spatially targeted interventions improve the effectiveness of environmental policy, but are challenged by implementation constraints and coordination among governments. Spatial targeting research rarely acknowledges the diversity of actors navigating complicated institutional dynamics to deploy environmental policy instruments. We mapped 35 nutrient reduction interventions by federal, state, county, and municipal governments and interviewed 15 policymakers and agency staff in Wisconsin{\textquoteright}s Yahara Watershed, USA to understand how multilevel governance impacts spatial targeting and implementation of water quality policy. Our Geographic Information System database showed that county governments implemented the most policies, while the state promulgated the most rules, with uneven application of policy interventions across the landscape. Spatial targeting differed between agricultural and non-agricultural policies and by type of tool (land acquisition, direct management, incentive, and regulation). We found a negative correlation between areas of policy intervention and phosphorus yield across government levels (p < 0.001), with the strongest negative correlations by implementing agency. Interviews revealed that for government agencies, spatial targeting is constrained by program and funding requirements and data limitations for soil and land use practices. In order to target the highest phosphorus yielding subwatersheds, governments will need to alter the spatial location of their efforts.},
	keywords = {Midwestern USA watershed, Multilevel governance, Spatial policy analysis, Surface water quality},
	isbn = {0169-2046},
	doi = {10.1016/j.landurbplan.2014.12.011},
	url = {http://www.sciencedirect.com/science/article/pii/S0169204614003090},
	author = {Wardropper, Chloe B. and Chang, Chaoyi and Rissman, Adena R.}
}
@article {95,
	title = {Planetary boundaries: Guiding human development on a changing planet},
	journal = {Science},
	volume = {347},
	year = {2015},
	month = {2015/02/13},
	abstract = {The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries{\textemdash}climate change and biosphere integrity{\textemdash}have been identified, each of which has the potential on its own to drive the Earth system into a new state should they be substantially and persistently transgressed.},
	doi = {10.1126/science.1259855},
	url = {http://www.sciencemag.org/content/347/6223/1259855.abstract},
	author = {Steffen, Will and Richardson, Katherine and Rockstr{\"o}m, Johan and Cornell, Sarah E. and Fetzer, Ingo and Bennett, Elena M. and Biggs, Reinette and Carpenter, Stephen R. and de Vries, Wim and de Wit, Cynthia A. and Folke, Carl and Gerten, Dieter and Heinke, Jens and Mace, Georgina M. and Persson, Linn M. and Ramanathan, Veerabhadran and Reyers, Belinda and S{\"o}rlin, Sverker}
}
@article {100,
	title = {Plausible futures of a social-ecological system: Yahara watershed, Wisconsin, USA},
	journal = {Ecology and Society},
	volume = {20},
	year = {2015},
	month = {2015},
	abstract = {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 km\&$\#$178;, population: 372,000) to assess its responses to multiple changing drivers. We measured recent trends in land use/cover and water quality of the watershed, spatial patterns of 10 ecosystem services, and spatial patterns and nestedness of governance. We developed scenarios for the future of the Yahara watershed by integrating trends and events from the global scenarios literature, perspectives of stakeholders, and models of biophysical drivers and ecosystem services. Four qualitative scenarios were created to explore plausible trajectories to the year 2070 in the watershed\&$\#$8217;s social-ecological system under different regimes: no action on environmental trends, accelerated technological development, strong intervention by government, and shifting values toward sustainability. Quantitative time-series for 2010\&$\#$8211;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.},
	keywords = {alternative futures, climate, ecosystem services, eutrophication, governance, lakes, land-use change, phosphorus, scenarios},
	doi = {10.5751/ES-07433-200210},
	url = {http://www.ecologyandsociety.org/vol20/iss2/art10/},
	author = {Carpenter, Stephen R. and Booth, Eric G. and Gillon, Sean and Kucharik, Christopher J. and Loheide, Steven and Mase, Amber S. and Motew, Melissa and Qiu, Jiangxiao and Rissman, Adena R. and Seifert, Jenny and Soylu, Evren and Turner, Monica and Wardropper, Chloe B.}
}
@article {102,
	title = {Progress on Nonpoint Pollution: Barriers \& Opportunities},
	journal = {Daedalus},
	volume = {144},
	year = {2015},
	abstract = {Nonpoint source pollution is the runoff of pollutants (including soil and nutrients) from agricultural, urban, and other lands (as opposed to point-source pollution, which comes directly from one outlet). Many efforts have been made to combat both types of pollution, so why are we making so little progress in improving water quality by reducing runoff of soil and nutrients into lakes and rivers? This essay examines the challenges inherent in: 1) producing science to predict and assess nonpoint management and policy effectiveness; and 2) using science for management and policy-making. Barriers to demonstrating causality include few experimental designs, different spatial scales for behaviors and measured outcomes, and lags between when policies are enacted and when their effects are seen. Primary obstacles to using science as evidence in nonpoint policy include disagreements about values and preferences, disputes over validity of assumptions, and institutional barriers to reconciling the supply and demand for science. We will illustrate some of these challenges and present possible solutions using examples from the Yahara Watershed in Wisconsin. Overcoming the barriers to nonpoint-pollution prevention may require policy-makers to gain a better understanding of existing scientific knowledge and act to protect public values in the face of remaining scientific uncertainty.},
	url = {http://www.mitpressjournals.org/loi/daed},
	author = {Rissman, Adena R. and Carpenter, Stephen R.}
}
@article {96,
	title = {Using a Simple Apparatus to Measure Direct and Diffuse Photosynthetically Active Radiation at Remote Locations},
	journal = {PLoS ONE},
	volume = {10},
	year = {2015},
	month = {2015/02/10},
	pages = {e0115633 - },
	abstract = {Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO<sub>2</sub>), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50\% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support ecological research via a relatively inexpensive method to collect continuous measurements of total, direct beam and diffuse PAR in remote locations.},
	doi = {10.1371/journal.pone.0115633},
	author = {Cruse, Michael J. and Kucharik, Christopher J. and Norman, John M.}
}
@article {78,
	title = {Extreme daily loads: role in annual phosphorus input to a north temperate lake},
	journal = {Aquatic Sciences},
	year = {2014},
	month = {2014/08/02},
	pages = {1-9},
	abstract = {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.},
	keywords = {Daily load extremes, Lake, Phosphorus load, Water quality},
	isbn = {1015-1621},
	doi = {10.1007/s00027-014-0364-5},
	url = {http://dx.doi.org/10.1007/s00027-014-0364-5},
	author = {Carpenter, Stephen R and Booth, Eric G and Kucharik, Christopher J and Lathrop, Richard C}
}
@article {69,
	title = {Phosphorus loading, transport and concentrations in a lake chain: a probabilistic model to compare management options},
	journal = {Aquatic Sciences},
	volume = {76},
	year = {2014},
	pages = {145-154},
	abstract = {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.},
	isbn = {1015-1621},
	doi = {10.1007/s00027-013-0324-5},
	url = {http://dx.doi.org/10.1007/s00027-013-0324-5},
	author = {Carpenter, S. R. and Lathrop, R. C.}
}
@article {77,
	title = {Regime Shift in Fertilizer Commodities Indicates More Turbulence Ahead for Food Security},
	journal = {PLOS One},
	volume = {9},
	year = {2014},
	month = {May},
	abstract = {Recent human population increase has been enabled by a massive expansion of global agricultural production. A key component of this "Green Revolution{\textquoteright}{\textquoteright} has been application of inorganic fertilizers to produce and maintain high crop yields. However, the long-term sustainability of these practices is unclear given the eutrophying effects of fertilizer runoff as well as the reliance of fertilizer production on finite non-renewable resources such as mined phosphate-and potassium-bearing rocks. Indeed, recent volatility in food and agricultural commodity prices, especially phosphate fertilizer, has raised concerns about emerging constraints on fertilizer production with consequences for its affordability in the developing world. We examined 30 years of monthly prices of fertilizer commodities (phosphate rock, urea, and potassium) for comparison with three food commodities (maize, wheat, and rice) and three non-agricultural commodities (gold, nickel, and petroleum). Here we show that all commodity prices, except gold, had significant change points between 2007-2009, but the fertilizer commodities, and especially phosphate rock, showed multiple symptoms of nonlinear critical transitions. In contrast to fertilizers and to rice, maize and wheat prices did not show significant signs of nonlinear dynamics. From these results we infer a recent emergence of a scarcity price in global fertilizer markets, a result signaling a new high price regime for these essential agricultural inputs. Such a regime will challenge on-going efforts to establish global food security but may also prompt fertilizer use practices and nutrient recovery strategies that reduce eutrophication.},
	isbn = {1932-6203},
	doi = {10.1371/journal.pone.0093998},
	url = {http://dx.doi.org/10.1371/journal.pone.0093998},
	author = {Elser, J. J. and Elser, T. J. and Carpenter, S. R. and Brock, W. A.}
}
@article {71,
	title = {Water quality implications from three decades of phosphorus loads and trophic dynamics in the Yahara chain of lakes},
	journal = {Inland Waters},
	volume = {4},
	year = {2014},
	pages = {1-14},
	abstract = {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{\textquoteright}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{\textquoteright}s outlet, reducing P loads in Mendota{\textquoteright}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.},
	issn = {2044-2041},
	doi = {10.5268/iw-4.1.680},
	url = {http://dx.doi.org/10.5268/iw-4.1.680},
	author = {Lathrop, R. C. and Carpenter, S. R.}
}
@article {67,
	title = {What is the influence on water quality in temperate eutrophic lakes of a reduction of planktivorous and benthivorous fish? A systematic review protocol},
	journal = {Environmental Evidence},
	volume = {2},
	year = {2013},
	abstract = {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.},
	doi = {10.1186/2047-2382-2-9},
	url = {http://www.environmentalevidencejournal.org/content/2/1/9},
	author = {Bernes, C. and Carpenter, S. R. and Gardmark, A. and Larsson, P. and Persson, L. and Skov, C. and Van Donk, E.}
}
@article {148,
	title = {Embodied phosphorus and the global connections of United States agriculture},
	journal = {Environmental Research Letters},
	volume = {7},
	year = {2012},
	month = {2012},
	pages = {044024},
	abstract = {Agricultural phosphorus (P) use is intricately linked to food security and water quality.Globalization of agricultural systems and changing diets clearly alter these relationships, yettheir specific influence on non-renewable P reserves is less certain. We assessed P fertilizer usedfor production of food crops, livestock and biofuels in the US agricultural system, explicitlycomparing the domestic P use required for US food consumption to the P use embodied in theproduction of US food imports and exports. By far the largest demand for P fertilizer throughout theUS agricultural system was for feed and livestock production (56\% of total P fertilizer use,including that for traded commodities). As little as 8\% of the total mineral P inputs to US domesticagriculture in 2007 (1905 Gg P) was consumed in US diets in the same year, while larger fractionsmay have been retained in agricultural soils (28\%), associated with different post-harvest losses(40\%) or with biofuel refining (10\%). One quarter of all P fertilizer used in the US was linked toexport production, primarily crops, driving a large net P flux out of the country (338 Gg P).However, US meat consumption relied considerably on P fertilizer use in other countries to producered meat imports. Changes in domestic farm management and consumer waste could together reduce the Pfertilizer required for US food consumption by half, which is comparable to the P fertilizerreduction attainable by cutting domestic meat consumption (44\%). US export-oriented agriculture,domestic post-harvest P losses and global demand for meat may ultimately have an important influenceon the lifespan of US phosphate rock reserves.},
	isbn = {1748-9326},
	doi = {10.1088/1748-9326/7/4/044024},
	url = {http://stacks.iop.org/1748-9326/7/i=4/a=044024},
	author = {Graham K MacDonald and Elena M Bennett and Stephen R Carpenter}
}
@article {68,
	title = {General Resilience to Cope with Extreme Events},
	journal = {Sustainability},
	volume = {4},
	year = {2012},
	pages = {3248-3259},
	abstract = {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.},
	isbn = {2071-1050},
	doi = {10.3390/su4123248},
	url = {http://dx.doi.org/10.3390/su4123248},
	author = {Carpenter, S. R. and Arrow, K. J. and Barrett, S. and Biggs, R. and Brock, W. A. and Crepin, A. S. and Engstrom, G. and Folke, C. and Hughes, T. P. and Kautsky, N. and Li, C. Z. and McCarney, G. and Meng, K. and Maler, K. G. and Polasky, S. and Scheffer, M. and Shogren, J. and Sterner, T. and Vincent, J. R. and Walker, B. and Xepapadeas, A. and de Zeeuw, A.}
}
@inbook {89,
	title = {Scenarios and Decisionmaking for Complex Environmental Systems},
	booktitle = {Environmental futures research: experiences, approaches, and opportunities},
	year = {2012},
	publisher = {U.S. Department of Agriculture, Forest Service, Northern Research Station},
	organization = {U.S. Department of Agriculture, Forest Service, Northern Research Station},
	address = {Newtown Square, PA},
	abstract = {Scenarios are used for expanding the scope of imaginable outcomes considered by assessments, planning exercises, or research projects on social-ecological systems. We discuss a global case study, the Millennium Ecosystem Assessment, and a regional
project for an urbanizing agricultural watershed. Qualitative and quantitative aspects of scenarios are complementary. Scenarios can help address several of the currently recognized challenges of sustainability science.},
	url = {http://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs-p-107.pdf},
	author = {Carpenter, Stephen R and Rissman, Adena R}
}
