TY - JOUR T1 - Scale-dependent interactions between tree canopy cover and impervious surfaces reduce daytime urban heat during summer JF - Proceedings of the National Academy of Sciences Y1 - 2019 A1 - Ziter, Carly D. A1 - Pedersen, Eric J. A1 - Kucharik, Christopher J. A1 - Turner, Monica G. KW - air temperature KW - ecosystem services KW - landscape context KW - urban forest KW - urban heat island AB - Cities worldwide are experiencing record-breaking summer air temperatures, with serious consequences for people. Increased tree cover is suggested as a climate adaptation strategy, but the amount of tree canopy cover needed to counteract higher temperatures associated with impervious surface cover is not known. We used a bicycle-mounted measurement system to quantify the interaction of canopy cover and impervious surface cover on urban air temperature. Daytime air temperature was substantially reduced with greater canopy cover (≥40%) at the scale of a typical city block (60–90 m), especially on the hottest days. However, reducing impervious surfaces remained important for lowering nighttime temperatures. Results can guide strategies for increasing tree cover to mitigate daytime urban heat and improve residents’ well-being.As cities warm and the need for climate adaptation strategies increases, a more detailed understanding of the cooling effects of land cover across a continuum of spatial scales will be necessary to guide management decisions. We asked how tree canopy cover and impervious surface cover interact to influence daytime and nighttime summer air temperature, and how effects vary with the spatial scale at which land-cover data are analyzed (10-, 30-, 60-, and 90-m radii). A bicycle-mounted measurement system was used to sample air temperature every 5 m along 10 transects (∼7 km length, sampled 3–12 times each) spanning a range of impervious and tree canopy cover (0–100%, each) in a midsized city in the Upper Midwest United States. Variability in daytime air temperature within the urban landscape averaged 3.5 °C (range, 1.1–5.7 °C). Temperature decreased nonlinearly with increasing canopy cover, with the greatest cooling when canopy cover exceeded 40%. The magnitude of daytime cooling also increased with spatial scale and was greatest at the size of a typical city block (60–90 m). Daytime air temperature increased linearly with increasing impervious cover, but the magnitude of warming was less than the cooling associated with increased canopy cover. Variation in nighttime air temperature averaged 2.1 °C (range, 1.2–3.0 °C), and temperature increased with impervious surface. Effects of canopy were limited at night; thus, reduction of impervious surfaces remains critical for reducing nighttime urban heat. Results suggest strategies for managing urban land-cover patterns to enhance resilience of cities to climate warming. UR - http://www.pnas.org/content/early/2019/03/19/1817561116.abstract JO - Proc Natl Acad Sci USA ER - TY - JOUR T1 - The synergistic effect of manure supply and extreme precipitation on surface water quality JF - Environmental Research Letters Y1 - 2018 A1 - Melissa Motew A1 - Eric G. Booth A1 - Stephen R. Carpenter A1 - Xi Chen A1 - Christopher J. Kucharik AB - 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<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. SN - 1748-9326 UR - http://iopscience.iop.org/10.1088/1748-9326/aaade6 ER - TY - JOUR T1 - Shifting drivers and static baselines in environmental governance: challenges for improving and proving water quality outcomes JF - Regional Environmental Change Y1 - 2016 A1 - Gillon, Sean A1 - Booth, Eric G. A1 - Rissman, Adena R. KW - Agricultural intensification KW - Climate change KW - Environmental governance KW - Land use change KW - Shifting drivers KW - Water quality AB - Understanding the conditions that enable or constrain success in environmental governance is crucial for developing effective interventions and adapting approaches. Efforts to achieve and assess success in environmental quality improvement are often impeded by changes in conditions that drive outcomes but lie outside the scope of intervention and monitoring. We document how long-term changes in land use, agriculture, and climate act as non-stationary, shifting drivers of change that combine to render water quality management interventions less effective and increasingly difficult to assess. Focusing on the Yahara River watershed of south-central Wisconsin, USA, we ask how baselines influence program modeling, monitoring, and evaluation, as well as adaptation in governance approach. Through historical trend, GIS, and policy and qualitative data analyses, we find that changes in long-term land use and precipitation pattern dynamics exert tremendous pressure on water quality outcomes but are not captured in snapshot baseline assessments used in management planning or evaluation. Specifically, agricultural sector change related to the intensification of milk and manure production is increasingly challenging to address through best management practices, and flashier precipitation associated with climate change makes it difficult to achieve goals and establish a causal connection between management interventions and outcomes. Analysis of shifting drivers demonstrates challenges facing environmental governance in the context of climatic and social–ecological change. We suggest that goal setting, program design, and evaluation incorporate new modes of analysis that address slowly changing and external determinants of success. VL - 16 SN - 1436-3798 UR - http://dx.doi.org/10.1007/s10113-015-0787-0 IS - 3 JO - Reg Environ Change ER - TY - JOUR T1 - Spatial fit between water quality policies and hydrologic ecosystem services in an urbanizing agricultural landscape JF - Landscape Ecology Y1 - 2016 A1 - Qiu, Jiangxiao A1 - Wardropper, Chloe B. A1 - Rissman, Adena R. A1 - Turner, Monica G. KW - Flood regulation KW - Freshwater KW - Groundwater quality KW - Groundwater recharge KW - landscape ecology KW - Policy targeting KW - Spatial overlap KW - Surface-water quality KW - Wisconsin KW - Yahara Watershed AB - Context Sustaining hydrologic ecosystem services is critical for human wellbeing but challenged by land use for agriculture and urban development. Water policy and management strive to safeguard hydrologic services, yet implementation is often fragmented. Understanding the spatial fit between water polices and hydrologic services is needed to assess the spatial targeting of policy portfolios at landscape scales. Objectives We investigated spatial fit between 30 different public water policies and four hydrologic services (surface and groundwater quality, freshwater supply, and flood regulation) in the Yahara Watershed (Wisconsin, USA)—a Midwestern landscape that typifies tensions between agriculture, urban development, and freshwater resources. Methods Spatial extent of water policy implementation was mapped, and indicators of hydrologic services were quantified for subwatersheds using empirical estimates and validated spatial models. Results We found a spatial misfit between the overall spatial implementation of water policy and regions of water quality concern, indicating a need for better targeting. Water quality policies can also be leveraged to protect other hydrologic services such as freshwater supply and flood regulation. Individual policy application areas varied substantially in their spatial congruence with each hydrologic service, indicating that not all services are protected by a single policy and highlighting the need for a broad spectrum of policies to sustain hydrologic services in diverse landscapes. We also identified where future policies could be targeted for improving hydrologic services. Conclusions Joint spatial analysis of policies and ecosystem services is effective for assessing spatial aspects of institutional fit, and provides a foundation for guiding future policy efforts. SN - 1572-9761 UR - http://dx.doi.org/10.1007/s10980-016-0428-0 JO - Landscape Ecology 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 - Soil Moisture Regime and Land Use History Drive Regional Differences in Soil Carbon and Nitrogen Storage Across Southern Wisconsin JF - Soil Science Y1 - 2013 A1 - Kucharik, C. J. A1 - Brye, K. R. AB - Agricultural land management can decrease soil organic carbon (SOC) and nitrogen (N) storage and adversely affect soil structure, but the actual impact can be confounded by the soil moisture regime. Wet or poorly drained soils tend to slow the process of organic matter oxidation and promote C storage, whereas comparatively drier or well-drained soils tend to promote organic matter turnover and C release. Therefore, the effects of land management, time since last disturbance, and soil moisture regime on near-surface soil bulk density (BD), SOC and total N (TN), and soil C:N ratios were evaluated across southern Wisconsin using a database generated during a 7-year period. Soil samples from the top 25 cm were collected from 169 sites consisting of prairie restorations and remnant prairies, Conservation Reserve Program land, agriculture (row crops and pasture), wetlands, and forests. Across all sites, soils with a udic soil moisture regime had lower (35%) native SOC, lower (31%) TN, greater (47%) BD, and lower (5.4%) soil C:N ratio than those with an aquic moisture regime. Agricultural (6.0 kg m(-2)) and restoration (5.8 kg m(-2)) sites had 30 and 32.3%, respectively, less SOC than native sites on udic soils, but agricultural (9.0 kg m(-2)) and restoration (8.8 kg m(-2)) sites with an aquic moisture regime shared similar SOC values with native sites under both udic (8.6 kg m(-2)) and aquic (10.6 kg m(-2)) moisture regimes. A 24.8% loss of native SOC attributed to agricultural land management occurred on aquic soils compared with a 33.6% loss on udic soils, and those effects were still present in prairie restorations. An apparent buffering capacity of wetter aquic soils on losses of C and N needs to be considered in quantifying soil C and N sequestration potential. VL - 178 UR - http://dx.doi.org/10.1097/ss.0000000000000015 IS - 9 ER - TY - JOUR T1 - Spatial interactions among ecosystem services in an urbanizing agricultural watershed JF - Proceedings of the National Academy of Sciences of the United States of America Y1 - 2013 A1 - Qiu, J. X. A1 - Turner, M. G. AB - Understanding spatial distributions, synergies, and tradeoffs of multiple ecosystem services (benefits people derive from ecosystems) remains challenging. We analyzed the supply of 10 ecosystem services for 2006 across a large urbanizing agricultural watershed in the Upper Midwest of the United States, and asked the following: (i) Where are areas of high and low supply of individual ecosystem services, and are these areas spatially concordant across services? (ii) Where on the landscape are the strongest tradeoffs and synergies among ecosystem services located? (iii) For ecosystem service pairs that experience tradeoffs, what distinguishes locations that are "win-win" exceptions from other locations? Spatial patterns of high supply for multiple ecosystem services often were not coincident; locations where six or more services were produced at high levels (upper 20th percentile) occupied only 3.3% of the landscape. Most relationships among ecosystem services were synergies, but tradeoffs occurred between crop production and water quality. Ecosystem services related to water quality and quantity separated into three different groups, indicating that management to sustain freshwater services along with other ecosystem services will not be simple. Despite overall tradeoffs between crop production and water quality, some locations were positive for both, suggesting that tradeoffs are not inevitable everywhere and might be ameliorated in some locations. Overall, we found that different areas of the landscape supplied different suites of ecosystem services, and their lack of spatial concordance suggests the importance of managing over large areas to sustain multiple ecosystem services. VL - 110 UR - http://dx.doi.org/10.1073/pnas.1310539110 IS - 29 ER - TY - CHAP T1 - Scenarios and Decisionmaking for Complex Environmental Systems T2 - Environmental futures research: experiences, approaches, and opportunities Y1 - 2012 A1 - Carpenter, Stephen R A1 - Rissman, Adena R AB - 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. JF - Environmental futures research: experiences, approaches, and opportunities PB - U.S. Department of Agriculture, Forest Service, Northern Research Station CY - Newtown Square, PA UR - http://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs-p-107.pdf ER -