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 - 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 - Quantifying indirect groundwater-mediated effects of urbanization on agroecosystem productivity using MODFLOW-AgroIBIS (MAGI), a complete critical zone model JF - Ecological Modeling Y1 - 2017 A1 - Zipper, Samuel C. A1 - Soylu, Mehmet Evren A1 - Kucharik, Christopher J. A1 - Loheide II, Steven P. KW - agroecosystem modeling KW - Dynamic vegetation models KW - Groundwater recharge KW - Groundwater-land surface coupling KW - Land use change KW - Urbanization AB - Sustainably accommodating future population growth and meeting global food requirements requires understanding feedbacks between ecosystems and belowground hydrological processes. Here, we introduce MODFLOW-AgroIBIS (MAGI), a new dynamic ecosystem model including groundwater flow, and use MAGI to explore the indirect impacts of land use change (urbanization) on landscape-scale agroecosystem productivity (corn yield). We quantify the degree to which urbanization can indirectly impact yield in surrounding areas by changing the amount of groundwater recharge locally and the water table dynamics at landscape scales. We find that urbanization can cause increases or decreases in yield elsewhere, with changes up to approximately +/− 40% under the conditions simulated due entirely to altered groundwater-land surface interactions. Our results indicate that land use change in upland areas has the largest impact on water table depth over the landscape. However, there is a spatial mismatch between areas with the largest water table response to urbanization elsewhere (upland areas) and locations with the strongest yield response to urbanization elsewhere (midslope areas). This mismatch arises from differences in baseline water table depth prior to urbanization. Yield response to urbanization in lowland areas is relatively localized despite large changes to the vertical water balance due to stabilizing ecohydrological feedbacks between root water uptake and lateral groundwater flow. These results demonstrate that hydrological impacts of land use change can propagate through subsurface flow to indirectly impact surrounding ecosystems, and these subsurface connections should be considered when planning land use at a landscape scale to avoid negative outcomes associated with land use change. VL - 359 SN - 0304-3800 UR - http://www.sciencedirect.com/science/article/pii/S0304380017300789 JO - Ecological Modelling 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 - Alternative scenarios of bioenergy crop production in an agricultural landscape and implications for bird communities JF - Ecological Applications Y1 - 2016 A1 - Blank, Peter J. A1 - Williams, Carol L. A1 - Sample, David W. A1 - Meehan, Timothy D. A1 - Turner, Monica G. KW - bioenergy crops KW - grass biomass KW - grassland birds KW - land-use change KW - landscape scenarios KW - row-crop agriculture KW - species of greatest conservation need AB - Increased demand and government mandates for bioenergy crops in the United States could require a large allocation of agricultural land to bioenergy feedstock production and substantially alter current landscape patterns. Incorporating bioenergy landscape design into land-use decision making could help maximize benefits and minimize trade-offs among alternative land uses. We developed spatially explicit landscape scenarios of increased bioenergy crop production in an 80-km radius agricultural landscape centered on a potential biomass-processing energy facility and evaluated the consequences of each scenario for bird communities. Our scenarios included conversion of existing annual row crops to perennial bioenergy grasslands and conversion of existing grasslands to annual bioenergy row crops. The scenarios explored combinations of four biomass crop types (three potential grassland crops along a gradient of plant diversity and one annual row crop [corn]), three land conversion percentages to bioenergy crops (10%, 20%, or 30% of row crops or grasslands), and three spatial configurations of biomass crop fields (random, clustered near similar field types, or centered on the processing plant), yielding 36 scenarios. For each scenario, we predicted the impact on four bird community metrics: species richness, total bird density, species of greatest conservation need (SGCN) density, and SGCN hotspots (SGCN birds/ha ≥ 2). Bird community metrics consistently increased with conversion of row crops to bioenergy grasslands and consistently decreased with conversion of grasslands to bioenergy row crops. Spatial arrangement of bioenergy fields had strong effects on the bird community and in some cases was more influential than the amount converted to bioenergy crops. Clustering grasslands had a stronger positive influence on the bird community than locating grasslands near the central plant or at random. Expansion of bioenergy grasslands onto marginal agricultural lands will likely benefit grassland bird populations, and bioenergy landscapes could be designed to maximize biodiversity benefits while meeting targets for biomass production. VL - 26 SN - 1939-5582 UR - http://dx.doi.org/10.1890/14-1490 IS - 1 ER - TY - JOUR T1 - From qualitative to quantitative environmental scenarios: Translating storylines into biophysical modeling inputs at the watershed scale JF - Environmental Modelling & Software Y1 - 2016 A1 - Booth, Eric G. A1 - Qiu, Jiangxiao A1 - Carpenter, Stephen R. A1 - Schatz, Jason A1 - Chen, Xi A1 - Kucharik, Christopher J. A1 - Loheide II, Steven P. A1 - Motew, Melissa M. A1 - Seifert, Jenny M. A1 - Turner, Monica G. KW - Biophysical modeling KW - Climate change KW - Land use change KW - scenarios KW - Social-ecological systems KW - Watershed AB - 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. VL - 85 SN - 1364-8152 UR - http://www.sciencedirect.com/science/article/pii/S1364815216304935 JO - Environmental Modelling & Software ER - TY - JOUR T1 - Reducing Phosphorus to Curb Lake Eutrophication is a Success JF - Environmental Science & Technology Y1 - 2016 A1 - Schindler, David W. A1 - Carpenter, Stephen R. A1 - Chapra, Steven C. A1 - Hecky, Robert E. A1 - Orihel, Diane M. AB - 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. VL - 50 SN - 0013-936X UR - http://dx.doi.org/10.1021/acs.est.6b02204 IS - 17 ER - TY - JOUR T1 - Urban heat island effects on growing seasons and heating and cooling degree days in Madison, Wisconsin USA JF - International Journal of Climatology Y1 - 2016 A1 - Schatz, Jason A1 - Kucharik, Christopher J. KW - cooling degree days KW - energy KW - freeze dates KW - growing degree days KW - growing season KW - heating degree days KW - urban climate KW - urban heat island AB - Urban areas tend to be warmer than their rural surroundings, a phenomenon known as the urban heat island (UHI) effect. UHIs are nearly always described in terms of temperature. However, UHIs can also be described using derived climate indices, including growing season length, growing degree days (GDDs), and heating and cooling degree days, which may have more direct ecological and economic significance than temperature alone. To characterize UHI effects on these basic climate parameters, we used over 3 years of continuously collected temperature data from up to 150 locations in and around Madison, Wisconsin, USA, an urban area of population 402 000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. Compared to rural areas, Madison's UHI extended the freeze-free season by several weeks each year. However, it only shifted the onset of spring and fall (represented by 10-day moving average temperature crossing seasonal thresholds) by 1 day or less in spring and by a few days to a week in fall. The different effects on freeze dates versus running-mean temperatures were primarily because the UHI could affect temperatures during individual freeze events much more than it could influence regional seasonal temperature trends. Urban effects on the meteorological growing season were nearly always greater in fall than in spring. We hypothesize that this is due to seasonal differences in sub-surface temperatures, with urban and rural areas presumably having more uniform sub-surface temperatures in spring after being frozen throughout the winter, contributing to weaker UHI effects in spring than in fall. In terms of degree days, densely built urban areas averaged 14% (209) more GDDs, 25% (117) more cooling degree days, and 6% (284) fewer heating degree days than rural areas, indicating that the UHI could have significant impacts on energy consumption in Madison. SN - 1097-0088 UR - http://dx.doi.org/10.1002/joc.4675 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 - Accounting for Results: How Conservation Organizations Report Performance Information JF - Environmental Management Y1 - 2015 A1 - Rissman, Adena R. A1 - Smail, Robert KW - Environmental governance KW - Evidence-based conservation KW - Land conservation KW - Monitoring and evaluation KW - Performance measurement KW - Policy outcomes AB - Environmental program performance information is in high demand, but little research suggests why conservation organizations differ in reporting performance information. We compared performance measurement and reporting by four private-land conservation organizations: Partners for Fish and Wildlife in the US Fish and Wildlife Service (national government), Forest Stewardship Council—US (national nonprofit organization), Land and Water Conservation Departments (local government), and land trusts (local nonprofit organization). We asked: (1) How did the pattern of performance reporting relationships vary across organizations? (2) Was political conflict among organizations’ principals associated with greater performance information? and (3) Did performance information provide evidence of program effectiveness? Based on our typology of performance information, we found that most organizations reported output measures such as land area or number of contracts, some reported outcome indicators such as adherence to performance standards, but few modeled or measured environmental effects. Local government Land and Water Conservation Departments reported the most types of performance information, while local land trusts reported the fewest. The case studies suggest that governance networks influence the pattern and type of performance reporting, that goal conflict among principles is associated with greater performance information, and that performance information provides unreliable causal evidence of program effectiveness. Challenging simple prescriptions to generate more data as evidence, this analysis suggests (1) complex institutional and political contexts for environmental program performance and (2) the need to supplement performance measures with in-depth evaluations that can provide causal inferences about program effectiveness. ER - TY - JOUR T1 - Creating a safe operating space for iconic ecosystems JF - Science Y1 - 2015 A1 - Scheffer, M. A1 - Barrett, S. A1 - Carpenter, S. R. A1 - Folke, C. A1 - Green, A. J. A1 - Holmgren, M. A1 - Hughes, T. P. A1 - Kosten, S. A1 - van de Leemput, I. A. A1 - Nepstad, D. C. A1 - van Nes, E. H. A1 - Peeters, E. T. H. M. A1 - Walker, B. VL - 347 UR - http://www.sciencemag.org/content/347/6228/1317.short IS - 6228 JO - Science ER - TY - JOUR T1 - Planetary boundaries: Guiding human development on a changing planet JF - Science Y1 - 2015 A1 - Steffen, Will A1 - Richardson, Katherine A1 - Rockström, Johan A1 - Cornell, Sarah E. A1 - Fetzer, Ingo A1 - Bennett, Elena M. A1 - Biggs, Reinette A1 - Carpenter, Stephen R. A1 - de Vries, Wim A1 - de Wit, Cynthia A. A1 - Folke, Carl A1 - Gerten, Dieter A1 - Heinke, Jens A1 - Mace, Georgina M. A1 - Persson, Linn M. A1 - Ramanathan, Veerabhadran A1 - Reyers, Belinda A1 - Sörlin, Sverker AB - 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—climate change and biosphere integrity—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. VL - 347 UR - http://www.sciencemag.org/content/347/6223/1259855.abstract IS - 6223 JO - Science 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 - Urban climate effects on extreme temperatures in Madison, Wisconsin, USA JF - Environmental Research Letters Y1 - 2015 A1 - Schatz, Jason A1 - Kucharik, Christopher J. AB - As climate change increases the frequency and intensity of extreme heat, cities and their urban heatisland (UHI) effects are growing, as are the urban populations encountering them. These mutuallyreinforcing trends present a growing risk for urban populations. However, we have limitedunderstanding of urban climates during extreme temperature episodes, when additional heat from theUHI may be most consequential. We observed a historically hot summer and historically cold winterusing an array of up to 150 temperature and relative humidity sensors in and around Madison,Wisconsin, an urban area of population 402 000 surrounded by lakes and a rural landscape ofagriculture, forests, wetlands, and grasslands. In the summer of 2012 (third hottest since 1869),Madison’s urban areas experienced up to twice as many hours ⩾32.2 °C (90 °F), mean July T MAX up to1.8 °C higher, and mean July T MIN up to 5.3 °C higher than rural areas. During a record settingheat wave, dense urban areas spent over four consecutive nights above the National Weather Servicenighttime heat stress threshold of 26.7 °C (80 °F), while rural areas fell below 26.7 °C nearlyevery night. In the winter of 2013–14 (coldest in 35 years), Madison’s most densely built urbanareas experienced up to 40% fewer hours ⩽−17.8 °C (0 °F), mean January T MAX up to 1 °C higher, andmean January T MIN up to 3 °C higher than rural areas. Spatially, the UHI tended to be most intensein areas with higher population densities. Temporally, both daytime and nighttime UHIs tended to beslightly more intense during more-extreme heat days compared to average summer days. These resultshelp us understand the climates for which cities must prepare in a warming, urbanizing world. VL - 10 SN - 1748-9326 UR - http://stacks.iop.org/1748-9326/10/i=9/a=094024 IS - 9 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 - Seasonality of the Urban Heat Island Effect in Madison, Wisconsin JF - Journal of Applied Meteorology and Climatology Y1 - 2014 A1 - Schatz, Jason A1 - Kucharik, Christopher J. AB - AbstractSpatial and temporal variation in the urban heat island (UHI) effect from March 2012 through October 2013 was characterized using continuous temperature measurements from an array of up to 151 fixed sensors in and around Madison, Wisconsin, an urban area of population 407 000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. Spatially, the density of the built environment was the primary driver of temperature patterns, with local modifying effects of lake proximity and topographic relief. Temporally, wind speed, cloud cover, relative humidity, soil moisture, and snow all influenced UHI intensity, although the magnitude and significance of their effects varied by season and time of day. Seasonally, UHI intensities tended to be higher during the warmer summer months and lower during the colder months. Seasonal trends in monthly average wind speed and cloud cover tracked annual trends in UHI intensity, with clearer, calmer conditions that are conducive to the stronger UHIs being more common during the summer. However, clear, calm summer nights still had higher UHI intensities than clear, calm winter nights, indicating that some background factor, such as vegetation, shifted baseline UHI intensities throughout the year. The authors propose that regional vegetation and snow-cover conditions set seasonal baselines for UHI intensity and that factors like wind and clouds modified daily UHI intensity around that baseline.AbstractSpatial and temporal variation in the urban heat island (UHI) effect from March 2012 through October 2013 was characterized using continuous temperature measurements from an array of up to 151 fixed sensors in and around Madison, Wisconsin, an urban area of population 407 000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. Spatially, the density of the built environment was the primary driver of temperature patterns, with local modifying effects of lake proximity and topographic relief. Temporally, wind speed, cloud cover, relative humidity, soil moisture, and snow all influenced UHI intensity, although the magnitude and significance of their effects varied by season and time of day. Seasonally, UHI intensities tended to be higher during the warmer summer months and lower during the colder months. Seasonal trends in monthly average wind speed and cloud cover tracked annual trends in UHI intensity, with clearer, calmer conditions that are conducive to the stronger UHIs being more common during the summer. However, clear, calm summer nights still had higher UHI intensities than clear, calm winter nights, indicating that some background factor, such as vegetation, shifted baseline UHI intensities throughout the year. The authors propose that regional vegetation and snow-cover conditions set seasonal baselines for UHI intensity and that factors like wind and clouds modified daily UHI intensity around that baseline. VL - 53 SN - 1558-8424 UR - http://dx.doi.org/10.1175/JAMC-D-14-0107.1 IS - 10 JO - J. Appl. Meteor. Climatol. 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 -