Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed continuum

Kaushal, Sujay S.; Delaney-Newcomb, Katie; Findlay, Stuart E. G.; Newcomer, Tamara A.; Duan, Shuiwang; Pennino, Michael J.; Sivirichi, Gwendolyn M.; Sides-Raley, Ashley M.; Walbridge, Mark R.; Belt, Kenneth T.

doi:10.1007/s10533-014-9979-9

Cited by 93 publications

(120 citation statements)

References 73 publications

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…The reason for the outlier GFCP is not clear, but a much better correlation between sediment ash-free dry weight and watershed ISC was reported in our previous study at the same Baltimore LTER sites (Duan and Kaushal et al, 2013). In any case, organic matter content in urban stream sediments was generally higher than in rural streams (also reported in Paul and Meyer, 2001), probably due to additional organic matter inputs from algal (Kaushal et al, 2014b) and anthropogenic sources (e.g., wastewater; Daniel et al, 2002). Our recent work showed that gross primary production and organic matter lability increased with watershed urbanization (Kaushal et al, 2014b).…”

Section: Changes In Salinization Effects With Watershed Urbanizationmentioning

confidence: 51%

“…In any case, organic matter content in urban stream sediments was generally higher than in rural streams (also reported in Paul and Meyer, 2001), probably due to additional organic matter inputs from algal (Kaushal et al, 2014b) and anthropogenic sources (e.g., wastewater; Daniel et al, 2002). Our recent work showed that gross primary production and organic matter lability increased with watershed urbanization (Kaushal et al, 2014b). Wastewater inputs from sewer leaks are common in the urban tributaries in the lower Gwynns Falls (DE-PRM and Baltimore City Department of Public Works, 2004; Kaushal et al, 2011).…”

Section: Changes In Salinization Effects With Watershed Urbanizationmentioning

confidence: 74%

“…Therefore, increasing ionic strength (or salinization) can enhance the solubility of the proteinaceous materials via sodium dispersion (Green et al, 2008(Green et al, , 2009a or through nonspecific electrostatic interactions at low salinities (called a "salting-in" effect) (Tanford, 1961;Chen et al, 1989). Furthermore, because stream sediments are generally enriched in these labile, proteinaceous materials derived from biofilms (algae and microbes) and wastewater organics in urban watersheds (Daniel et al, 2002;Kaushal et al, 2011Kaushal et al, , 2014bKaushal and Belt, 2012;Newcomer et al, 2012;, it is reasonable that salinization can mobilize a large amount of protein-like labile dissolved organic matter from stream sediments. Relative to the proteinaceous materials, humic substances are larger hydrophobic molecules occurring in the colloidal size range (e.g., Aiken et al, 1985).…”

Section: S Duan and S S Kaushal: Salinization Alters Fluxes Of Biomentioning

confidence: 99%

See 2 more Smart Citations

Salinization alters fluxes of bioreactive elements from stream ecosystems across land use

Duan

Kaushal

2015

Biogeosciences

View full text Add to dashboard Cite

Abstract. There has been increased salinization of fresh water over decades due to the use of road salt deicers, wastewater discharges, saltwater intrusion, human-accelerated weathering, and groundwater irrigation. Salinization can mobilize bioreactive elements (carbon, nitrogen, phosphorus, sulfur) chemically via ion exchange and/or biologically via influencing of microbial activity. However, the effects of salinization on coupled biogeochemical cycles are still not well understood. We investigated potential impacts of increased salinization on fluxes of bioreactive elements from stream ecosystems (sediments and riparian soils) to overlying stream water and evaluated the implications of percent urban land use on salinization effects. Two-day incubations of sediments and soils with stream and deionized water across three salt levels were conducted at eight routine monitoring stations across a land-use gradient at the Baltimore Ecosystem Study Long-Term Ecological Research (LTER) site in the Chesapeake Bay watershed. Results indicated (1) salinization typically increased sediment releases of labile dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), total dissolved Kjeldahl nitrogen (TKN) (ammonium + ammonia + dissolved organic nitrogen), and sediment transformations of nitrate; (2) salinization generally decreased DOC aromaticity and fluxes of soluble reactive phosphorus from both sediments and soils; (3) the effects of increased salinization on sediment releases of DOC and TKN and DOC quality increased with percentage watershed urbanization. Biogeochemical responses to salinization varied between sediments and riparian soils in releases of DOC and DIC, and nitrate transformations. The differential responses of riparian soils and sediments to increased salinization were likely due to differences in organic matter sources and composition. Our results suggest that short-term increases in salinization can cause releases of significant amounts of labile organic carbon and nitrogen from stream substrates and organic transformations of nitrogen and phosphorus in urban watersheds. Given that salinization of fresh water will increase in the future due to human activities, significant impacts on carbon and nutrient mobilization and water quality should be anticipated.

show abstract

Section: Changes In Salinization Effects With Watershed Urbanizationmentioning

confidence: 51%

Section: Changes In Salinization Effects With Watershed Urbanizationmentioning

confidence: 74%

Section: S Duan and S S Kaushal: Salinization Alters Fluxes Of Biomentioning

confidence: 99%

See 1 more Smart Citation

Salinization alters fluxes of bioreactive elements from stream ecosystems across land use

Duan

Kaushal

2015

Biogeosciences

View full text Add to dashboard Cite

show abstract

“…4; Kaushal and Belt 2012). This leads to cascading impacts of heterogeneity on the water chemistry and ecosystem functions of urban watersheds across longitudinal, lateral, and vertical dimensions as well as through time (Kaushal and Belt 2012;Kaushal et al 2014a): 1) Longitudinally, there can be significantly enhanced Bhot spots^of gross primary production along the urban watershed continuum up to five times greater than forest streams due to light availability, which can be heterogeneous due to patchy riparian cover (Kaushal et al 2014a). 2) Laterally, downcutting of urban streams due to the flashy delivery of rainwater from impervious surfaces typically disconnects the stream from its former floodplain.…”

Section: The Urban Engineered Watershed: a Specific Model For Integramentioning

confidence: 99%

Dynamic heterogeneity: a framework to promote ecological integration and hypothesis generation in urban systems

et al. 2016

View full text Add to dashboard Cite

Urban areas are understood to be extraordinarily spatially heterogeneous. Spatial heterogeneity, and its causes, consequences, and changes, are central to ecological science. The social sciences and urban design and planning professions also include spatial heterogeneity as a key concern. However, urban ecology, as a pursuit that integrates across these disciplines, lacks a theoretical framework that synthesizes the diverse and important aspects of heterogeneity. This paper presents the concept of dynamic heterogeneity as a tool to explore how social and ecological heterogeneities interact and how they together act as both an outcome of past interactions and a driver future heterogeneity and system functions. To accomplish this goal, we relate heterogeneity to the fundamental concept of the human ecosystem. The human ecosystem concept identifies key processes that require operationalized models of dynamic heterogeneity in three process realms: the flow of materials, the assembly of urban ecosystem biota, and the locational choices humans make concerning land. We exemplify a specific dynamic model of heterogeneity in each of these realms, and indicate a range of complementary statistical approaches to integrate the drivers and outcomes of dynamic heterogeneity across the three realms. We synthesize a hierarchical framework for a theory of dynamic urban heterogeneity, noting its complementarity to other major urban theories and general model approaches. We hypothesize that human actions and structures amplify the dynamics of heterogeneity in urban systems.

show abstract

“…For example, research has characterized ecosystem functions such as nitrogen uptake, denitrification, and ecosystem metabolism in buried streams, storm drains, and stormwater management controls [37,42,[48][49][50]. Other work has investigated broader spatial patterns in transport and transformation of materials along natural and engineered hydrologic flowpaths of the urban watershed continuum [45,51,52]. Finally, recent work has also proposed that the urban watershed continuum can be a useful tool for guiding watershed management and ecosystem restoration by recognizing a distinct hydrology and ecology along urban hydrologic flowpaths [50,53].…”

Section: Urban Waters: From Syndrome To Continuummentioning

confidence: 99%

Urban Evolution: The Role of Water

Kaushal

McDowell

Wollheim

et al. 2015

Water

View full text Add to dashboard Cite

Abstract:The structure, function, and services of urban ecosystems evolve over time scales from seconds to centuries as Earth's population grows, infrastructure ages, and sociopolitical values alter them. In order to systematically study changes over time, the concept of "urban evolution" was proposed. It allows urban planning, management, and restoration to move beyond reactive management to predictive management based on past observations of consistent patterns. Here, we define and review a glossary of core concepts for studying urban evolution, which includes the mechanisms of urban selective pressure and urban adaptation. Urban selective pressure is an environmental or societal driver contributing to urban adaptation. Urban adaptation is the sequential process by which an urban structure, function, or services becomes more fitted to its changing environment or human choices. The role of water is vital to driving urban evolution as demonstrated by historical changes in drainage, sewage flows, hydrologic pulses, and long-term chemistry. In the current paper, we show how hydrologic traits evolve across successive generations of urban ecosystems OPEN ACCESSWater 2015, 7 4064 via shifts in selective pressures and adaptations over time. We explore multiple empirical examples including evolving: (1) urban drainage from stream burial to stormwater management; (2) sewage flows and water quality in response to wastewater treatment; (3) amplification of hydrologic pulses due to the interaction between urbanization and climate variability; and (4) salinization and alkalinization of fresh water due to human inputs and accelerated weathering. Finally, we propose a new conceptual model for the evolution of urban waters from the Industrial Revolution to the present day based on empirical trends and historical information. Ultimately, we propose that water itself is a critical driver of urban evolution that forces urban adaptation, which transforms the structure, function, and services of urban landscapes, waterways, and civilizations over time.

show abstract

Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed continuum

Cited by 93 publications

References 73 publications

Salinization alters fluxes of bioreactive elements from stream ecosystems across land use

Salinization alters fluxes of bioreactive elements from stream ecosystems across land use

Dynamic heterogeneity: a framework to promote ecological integration and hypothesis generation in urban systems

Urban Evolution: The Role of Water

Contact Info

Product

Resources

About