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 - Continuous separation of land use and climate effects on the past and future water balance JF - Journal of Hydrology Y1 - 2018 A1 - Zipper, Samuel C. A1 - Motew, Melissa A1 - Booth, Eric G. A1 - Chen, Xi A1 - Qiu, Jiangxiao A1 - Kucharik, Christopher J. A1 - Carpenter, Stephen R. A1 - Loheide II, Steven P. KW - Baseflow KW - Climate change KW - Evapotranspiration KW - Land use change KW - Streamflow KW - Urbanization AB - 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. VL - 565 UR - http://www.sciencedirect.com/science/article/pii/S0022169418306188 ER - TY - JOUR T1 - Current and historical land use influence soil‐based ecosystem services in an urban landscape JF - Ecological Applications Y1 - 2018 A1 - Ziter, Carly A1 - Turner, Monica G. KW - carbon KW - ecosystem services KW - Historical ecology KW - land‐use change KW - phosphorus KW - runoff regulation KW - saturated hydraulic conductivity KW - soil KW - Urban ecosystems KW - Water quality AB - Abstract Urban landscapes are increasingly recognized as providing important ecosystem services (ES) to their occupants. Yet, urban ES assessments often ignore the complex spatial heterogeneity and land?use history of cities. Soil?based services may be particularly susceptible to land?use legacy effects. We studied indicators of three soil?based ES, carbon storage, water quality regulation, and runoff regulation, in a historically agricultural urban landscape and asked (1) How do ES indicators vary with contemporary land cover and time since development? (2) Do ES indicators vary primarily among land?cover classes, within land?cover classes, or within sites? (3) What is the relative contribution of urban land?cover classes to potential citywide ES provision? We measured biophysical indicators (soil carbon [C], available phosphorus [P], and saturated hydraulic conductivity [Ks]) in 100 sites across five land?cover classes, spanning an ~125?year gradient of time since development within each land?cover class. Potential for ES provision was substantial in urban green spaces, including developed land. Runoff regulation services (high Ks) were highest in forests; water quality regulation (low P) was highest in open spaces and grasslands; and open spaces and developed land (e.g., residential yards) had the highest C storage. In developed land covers, both C and P increased with time since development, indicating effects of historical land?use on contemporary ES and trade?offs between two important ES. Among?site differences accounted for a high proportion of variance in soil properties in forests, grasslands, and open space, while residential areas had high within?site variability, underscoring the leverage city residents have to improve urban ES provision. Developed land covers contributed most ES supply at the citywide scale, even after accounting for potential impacts of impervious surfaces. Considering the full mosaic of urban green space and its history is needed to estimate the kinds and magnitude of ES provided in cities, and to augment regional ES assessments that often ignore or underestimate urban ES supply. SN - 1051-0761 UR - https://doi.org/10.1002/eap.1689 JO - Ecological Applications 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 -