02250nas a2200253   4500008004100000020001400041245008000055210006900135260001300204300001400217490000700231520146400238653002401702653002801726653002801754653001501782653001601797653001801813653002801831100002601859700001701885700002301902856007101925       2017                        eng d  a0264-837700aUncertain monitoring and modeling in a watershed nonpoint pollution program0 aUncertain monitoring and modeling in a watershed nonpoint pollut  c2017/9//  a690 - 7010 v673 aPerformance-based programs governing land use rely on environmental measurement, prediction, and assessment. Yet complex, nonlinear social and environmental change can lead to uncertainties in quantification and forecasting and create challenges for operationalizing programs. This research examines the roles that environmental monitoring and modeling uncertainty play in experimental land and water governance through an analysis of a regulatory water quality program in Wisconsin, USA. The case demonstrates how uncertainties in measurement and prediction of pollution runoff shape program design and participant perceptions. We draw on interviews, a survey, participant observation, and policy document analysis to illustrate how regulators and participants (including municipalities, sewerage treatment plants, farmers and nonprofit organizations) perceive and react to uncertainty. Because current and future water quality data are based largely on model estimates, but regulatory compliance will likely be based on measured in-stream outcomes, participants must evaluate potential risks of involvement. Stakeholders have relied on partnership building and legal modifications such as extended compliance timelines to reduce the risks associated with uncertainty. Experimentation under uncertainty led to sustained stakeholder dialogue, and an iterative process of deciding how monitoring and modeling should be used to track and prove program progress.10aAdaptive governance10aExperimental governance10aPerformance measurement10aRegulation10aUncertainty10aWater quality10aWatershed collaboration1 aWardropper, Chloe, B.1 aGillon, Sean1 aRissman, Adena, R.  uhttp://www.sciencedirect.com/science/article/pii/S026483771631204201830nas a2200253   4500008004100000020001400041245006900055210006800124260000900192520107000201653001701271653002001288653003301308653002201341653001801363653002201381653001801403653001701421100002301438700001801461700003001479700002401509856004301533       2017                        eng d  a1944-800700aUrban heat island-induced increases in evapotranspirative demand0 aUrban heat islandinduced increases in evapotranspirative demand  c20173 aAlthough 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.10aecohydrology10aplant water use10areference evapotranspiration10aurban climatology10aurban ecology10aurban heat island10aUrban systems10aWater supply1 aZipper, Samuel, C.1 aSchatz, Jason1 aKucharik, Christopher, J.1 aLoheide, Steven, P.  uhttp://dx.doi.org/10.1002/2016GL07219002649nas a2200229   4500008004100000020001400041245011100055210006900166260000900235520192900244653002402173653001102197653001702208653002402225653001902249653002402268653001802292653002202310100001802332700003002350856003902380       2016                        eng d  a1097-008800aUrban heat island effects on growing seasons and heating and cooling degree days in Madison, Wisconsin USA0 aUrban heat island effects on growing seasons and heating and coo  c20163 aUrban 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.10acooling degree days10aenergy10afreeze dates10agrowing degree days10agrowing season10aheating degree days10aurban climate10aurban heat island1 aSchatz, Jason1 aKucharik, Christopher, J.  uhttp://dx.doi.org/10.1002/joc.467502269nas a2200289   4500008004100000020001400041245010100055210006900156260000900225300001100234490000700245520139300252653002701645653001901672653001901691653001801710653001801728653002201746653002501768100002201793700001801815700001801833700002901851700002401880700002301904856005201927       2016                        eng d  a1748-932600aUrban heat island impacts on plant phenology: intra-urban variability and response to land cover0 aUrban heat island impacts on plant phenology intraurban variabil  c2016  a0540230 v113 aDespite 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.10aland surface phenology10aremote sensing10asensor network10aurban climate10aurban ecology10aurban heat island10avegetation phenology1 aZipper, Samuel, C1 aSchatz, Jason1 aSingh, Aditya1 aKucharik, Christopher, J1 aTownsend, Philip, A1 aLoheide, Steven, P  uhttp://stacks.iop.org/1748-9326/11/i=5/a=05402302622nas a2200277   4500008004100000020001400041245011400055210006900169260001200238520171500250653003001965653002401995653002302019653003102042653002702073653001702100653001402117653002602131653003602157653001602193100002302209700002502232700002002257700002402277856004302301       2015                        eng d  a1944-797300aUntangling the effects of shallow groundwater and soil texture as drivers of subfield-scale yield variability0 aUntangling the effects of shallow groundwater and soil texture a  c07/20153 aWater 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.10a0402 Agricultural systems10a0486 Soils/pedology10a1813 Eco-hydrology10a1829 Groundwater hydrology10aagroecosystem modeling10aAgroIBIS-VSF10aHydrus-1D10aPrecision agriculture10asoil-plant-atmosphere continuum10awater table1 aZipper, Samuel, C.1 aSoylu, Mehmet, Evren1 aBooth, Eric, G.1 aLoheide, Steven, P.  uhttp://dx.doi.org/10.1002/2015WR01752202245nas a2200157   4500008004100000020001400041245007700055210006900132260000900201300001100210490000700221520175900228100001801987700003002005856005202035       2015                        eng d  a1748-932600aUrban climate effects on extreme temperatures in Madison, Wisconsin, USA0 aUrban climate effects on extreme temperatures in Madison Wiscons  c2015  a0940240 v103 aAs 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.1 aSchatz, Jason1 aKucharik, Christopher, J.  uhttp://stacks.iop.org/1748-9326/10/i=9/a=09402402700nas a2200157   4500008004100000245011500041210006900156260001500225300001600240490000700256520216200263100002302425700003002448700002102478856004302499       2015                        eng d00aUsing a Simple Apparatus to Measure Direct and Diffuse Photosynthetically Active Radiation at Remote Locations0 aUsing a Simple Apparatus to Measure Direct and Diffuse Photosynt  c2015/02/10  ae0115633 - 0 v103 aPlant 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.1 aCruse, Michael, J.1 aKucharik, Christopher, J.1 aNorman, John, M.  uhttps://wsc.limnology.wisc.edu/node/9602747nas a2200241   4500008004100000020001400041245013800055210006900193260000900262300001100271490000800282520193800290653002102228653001902249653002302268653002602291653002602317653002002343653002102363100002302384700002702407856007102434       2014                        eng d  a0168-192300aUsing evapotranspiration to assess drought sensitivity on a subfield scale with HRMET, a high resolution surface energy balance model0 aUsing evapotranspiration to assess drought sensitivity on a subf  c2014  a91-1020 v1973 aAbstract Evapotranspiration (ET) rates provide a valuable within-season indicator of plant productivity, as well as data on fluxes of water in a landscape. Applying remote sensing for ET estimation has potential to improve the sustainable management of water resources in agricultural settings. Most current ET models, however, rely on ‘dry’ and ‘wet’ pixels within a given scene to partition turbulent fluxes between latent and sensible heat, thus limiting their ability to map ET throughout the growing season at extremely high (meter scale) spatial resolutions. Here, we develop a field-validated surface energy balance model, High Resolution Mapping of EvapoTranspiration (HRMET), which requires only basic meteorological data, spatial surface temperature and canopy structure data. We use HRMET to estimate ET rates over two commercial cornfields in south-central Wisconsin during the 2012 growing season, which was characterized by severe drought. HRMET results indicate that the magnitude of within-field variability in ET rates was primarily driven by water availability. The application of remotely sensed data to precision agriculture has also been hampered by turnaround time between image acquisition and availability. We introduce relative ET (ETR), which enables comparison of ET rates between image dates by normalizing for variability caused by weather and crop stage. ETR also provides an intuitive, index-like metric for evaluating spatial variability in ET on a subfield scale. ETR maps illuminate persistent patterns in ET across measurement dates that may be driven by soil water availability and topography. ETR is used to develop a novel paired-image technique that can map subfield sensitivity classes to stressors such as drought. Sensitivity class mapping can be used to circumvent issues related to turnaround time to facilitate the incorporation of remotely sensed data into precision agriculture.10aDrought response10aEnergy balance10aEvapotranspiration10aPrecision agriculture10aSpatial heterogeneity10aThermal imagery10aYield monitoring1 aZipper, Samuel, C.1 aII, Steven, P. Loheide  uhttp://www.sciencedirect.com/science/article/pii/S0168192314001518