James Brendan Heffernan

Journal Article Ecosystems · March 1, 2024 Relatively unmanaged interstitial areas at the residential–wildland interface can support the development of novel woody plant communities. Community assembly processes in urban areas involve interactions between spontaneous and cultivated species pools th ... Full text Cite

Sustainability and Biodiversity

Chapter · January 1, 2024 Extraordinary rates of biodiversity loss, coupled with rising human population and consumption rates, threaten the sustainability of Earth's life support systems. An inclusive wealth framework that considers the current and future stocks and flows of human ... Full text Cite

North Carolina Coastal Plain Ditch Types Support Distinct Hydrophytic Communities

Journal Article Wetlands · June 1, 2023 The drainage ditches of the North Carolina Coastal Plain retain ecological structural characteristics of the wetlands they often replace. We surveyed 32 agricultural, freeway, and forested ditch reaches across this region for hydrologic indicators, soil or ... Full text Cite

Carbonates in the Critical Zone

Journal Article Earth's Future · January 1, 2023 Earth's Critical Zone (CZ), the near-surface layer where rock is weathered and landscapes co-evolve with life, is profoundly influenced by the type of underlying bedrock. Previous studies employing the CZ framework have focused primarily on landscapes domi ... Full text Cite

A simple metric for predicting the timing of river phytoplankton blooms

Journal Article Ecosphere · December 1, 2022 In rivers, phytoplankton populations are continuously exported by unidirectional, advective flow. Both transport and growth conditions determine periods of excess phytoplankton growth, or blooms, in a given reach. Phytoplankton abundance, however, has main ... Full text Cite

Respiration regimes in rivers: Partitioning source-specific respiration from metabolism time series

Journal Article Limnology and Oceanography · November 1, 2022 Respiration in streams is controlled by the timing, magnitude, and quality of organic matter (OM) inputs from internal primary production and external fluxes. Here, we estimated the contribution of different OM sources to seasonal, annual, and event-driven ... Full text Cite

People, infrastructure, and data: A pathway to an inclusive and diverse ecological network of networks

Journal Article Ecosphere · November 1, 2022 Macrosystem-scale research is supported by many ecological networks of people, infrastructure, and data. However, no network is sufficient to address all macrosystems ecology research questions, and there is much to be gained by conducting research and sha ... Full text Cite

Climate-Driven Variations in Nitrogen Retention From a Riverine Submerged Aquatic Vegetation Meadow

Journal Article Water Resources Research · October 1, 2022 Large rivers can retain a substantial amount of nitrogen (N), particularly in submerged aquatic vegetation (SAV) meadows that may act as disproportionate control points for N retention. However, the temporal variation of N retention in large rivers remains ... Full text Cite

Ecological homogenization of soil properties in the American residential macrosystem

Journal Article Ecosphere · September 1, 2022 The conversion of native ecosystems to residential ecosystems dominated by lawns has been a prevailing land-use change in the United States over the past 70 years. Similar development patterns and management of residential ecosystems cause many characteris ... Full text Cite

Propagation of inflowing urban stormwater pulses through reservoir embayments

Journal Article Urban Ecosystems · August 1, 2022 Flashy hydrology and high solute loads in stormflow are well-studied effects of the built environment on urban streams. The physical and chemical interactions between inflowing stormwater of urban streams and their termination in large impoundments, howeve ... Full text Cite

Light and flow regimes regulate the metabolism of rivers.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · February 2022 Mean annual temperature and mean annual precipitation drive much of the variation in productivity across Earth's terrestrial ecosystems but do not explain variation in gross primary productivity (GPP) or ecosystem respiration (ER) in flowing waters. We doc ... Full text Cite

Nonlinear dynamics, resilience, and regime shifts in aquatic communities and ecosystems: an overview

Journal Article Limnology and Oceanography · February 1, 2022 Full text Cite

Residential yard management and landscape cover affect urban bird community diversity across the continental USA.

Journal Article Ecological applications : a publication of the Ecological Society of America · December 2021 Urbanization has a homogenizing effect on biodiversity and leads to communities with fewer native species and lower conservation value. However, few studies have explored whether or how land management by urban residents can ameliorate the deleterious effe ... Full text Cite

A Multiscale Approach to Timescale Analysis: Isolating Diel Signals from Solute Concentration Time Series.

Journal Article Environmental science & technology · September 2021 Solute concentration time series reflect hydrological and biological drivers through various frequencies, phases, and amplitudes of change. Untangling these signals facilitates the understanding of dynamic ecosystem conditions and transient water quality i ... Full text Cite

Estimating Benthic Light Regimes Improves Predictions of Primary Production and constrains Light-Use Efficiency in Streams and Rivers

Journal Article Ecosystems · June 1, 2021 Light-use efficiency (LUE) describes conversion of incident light into gross primary production (GPP), combining the inherent photosynthetic efficiency of chloroplasts with light-capture ability of the autotrophic community. In lotic ecosystems, LUE is poo ... Full text Cite

A seasonally dynamic model of light at the stream surface

Journal Article Freshwater Science · June 1, 2021 Light is a primary constraint on primary production and drives many ecological processes in stream ecosystems, yet light regimes have received considerably less attention than other factors of the stream environment, such as hydrology or nutrient cycling. ... Full text Cite

Hypoxia dynamics and spatial distribution in a low gradient river

Journal Article Limnology and Oceanography · June 1, 2021 Deoxygenation of aquatic ecosystems is a key feature of the Anthropocene. Studies are increasingly reporting low oxygen conditions in rivers and headwater streams even in the absence of high nutrient loads. We examined the frequency of river hypoxia (disso ... Full text Cite

Competition Among Limestone Depressions Leads to Self-Organized Regular Patterning on a Flat Landscape

Journal Article Journal of Geophysical Research: Earth Surface · May 1, 2021 Self-organized pattern formation is widespread and functionally significant. Scale-dependent feedback in space (short-distance positive feedback coupled with long-distance negative feedback) has been embraced as an arguably universal mechanism of ecologica ... Full text Cite

Municipal regulation of residential landscapes across US cities: Patterns and implications for landscape sustainability.

Journal Article Journal of environmental management · December 2020 Local regulations on residential landscapes (yards and gardens) can facilitate or constrain ecosystem services and disservices in cities. To our knowledge, no studies have undertaken a comprehensive look at how municipalities regulate residential landscape ... Full text Cite

How Old Are Marshes on the East Coast, USA? Complex Patterns in Wetland Age Within and Among Regions

Journal Article Geophysical Research Letters · October 16, 2020 Sea-level dynamics, sediment availability, and marine energy are critical drivers of coastal wetland formation and persistence, but their roles as continental-scale drivers remain unknown. We evaluated the timing and spatial variability of wetland formatio ... Full text Cite

Woody Plant–Soil Relationships in Interstitial Spaces Have Implications for Future Forests Within and Beyond Urban Areas

Sustainability and Biodiversity

North Carolina Coastal Plain Ditch Types Support Distinct Hydrophytic Communities

Carbonates in the Critical Zone

A simple metric for predicting the timing of river phytoplankton blooms

Respiration regimes in rivers: Partitioning source-specific respiration from metabolism time series

People, infrastructure, and data: A pathway to an inclusive and diverse ecological network of networks

Climate-Driven Variations in Nitrogen Retention From a Riverine Submerged Aquatic Vegetation Meadow

Ecological homogenization of soil properties in the American residential macrosystem

Propagation of inflowing urban stormwater pulses through reservoir embayments

Light and flow regimes regulate the metabolism of rivers.

Nonlinear dynamics, resilience, and regime shifts in aquatic communities and ecosystems: an overview

Journal Article Limnology and Oceanography · February 1, 2022 Full text Cite

Residential yard management and landscape cover affect urban bird community diversity across the continental USA.

A Multiscale Approach to Timescale Analysis: Isolating Diel Signals from Solute Concentration Time Series.

Estimating Benthic Light Regimes Improves Predictions of Primary Production and constrains Light-Use Efficiency in Streams and Rivers

A seasonally dynamic model of light at the stream surface

Hypoxia dynamics and spatial distribution in a low gradient river

Competition Among Limestone Depressions Leads to Self-Organized Regular Patterning on a Flat Landscape

Municipal regulation of residential landscapes across US cities: Patterns and implications for landscape sustainability.

How Old Are Marshes on the East Coast, USA? Complex Patterns in Wetland Age Within and Among Regions

Bioavailability and compositional changes of dissolved organic matter in urban headwaters

Journal Article Aquatic Sciences · October 1, 2020 In urban stream networks, the headwaters are comprised of engineered headwaters where particulate organic matter collects during and between storms. During storms, dissolved organic matter leached from these pools is transported to the stream as stormflow ... Full text Cite

Interactions Between Physical Template and Self-organization Shape Plant Dynamics in a Stream Ecosystem

Journal Article Ecosystems · June 1, 2020 Both internal feedbacks and preexisting heterogeneity of a physical template can produce biological patchiness in ecosystems. The relative importance of the two drivers might change over time, in response to changes in the external environment. This is esp ... Full text Cite

Urban soil carbon and nitrogen converge at a continental scale

Journal Article Ecological Monographs · May 1, 2020 In urban areas, anthropogenic drivers of ecosystem structure and function are thought to predominate over larger-scale biophysical drivers. Residential yards are influenced by individual homeowner preferences and actions, and these factors are hypothesized ... Full text Cite

Watershed and ocean controls of salt marsh extent and resilience

Journal Article Earth Surface Processes and Landforms · May 1, 2020 The formation and evolution of tidal platforms are controlled by the feedbacks between hydrodynamics, geomorphology, vegetation, and sediment transport. Previous work mainly addresses dynamics at the scale of individual marsh platforms. Here, we develop a ... Full text Cite

Ecohydrologic processes and soil thickness feedbacks control limestone-weathering rates in a karst landscape

Journal Article Chemical Geology · November 20, 2019 Chemical weathering of bedrock plays an essential role in the formation and evolution of Earth's critical zone. Over geologic time, the negative feedback between temperature and chemical weathering rates contributes to the regulation of Earth climate. The ... Full text Cite

Mass balance implies Holocene development of a low-relief karst patterned landscape

Journal Article Chemical Geology · November 20, 2019 We constructed mass balances of both calcium and phosphorus for two watersheds in Big Cypress National Preserve in southwest Florida (USA) to evaluate the time scales over which its striking landscape pattern developed. This low-relief carbonate landscape ... Full text Cite

Stoichiometry and daily rhythms: experimental evidence shows nutrient limitation decouples N uptake from photosynthesis.

Journal Article Ecology · October 2019 Diel variability in nutrient concentrations is common but not universal in aquatic ecosystems. Theoretical models of photoautotrophic systems attribute the absence of diel uptake variation to nutrient scarcity, such that diel variability in nutrient uptake ... Full text Cite

Emergent productivity regimes of river networks

Journal Article Limnology And Oceanography Letters · October 1, 2019 High-resolution data are improving our ability to resolve temporal patterns and controls on river productivity, but we still know little about the emergent patterns of primary production at river-network scales. Here, we estimate daily and annual river-net ... Full text Open Access Cite

Coastal Wetland Distributions: Delineating Domains of Macroscale Drivers and Local Feedbacks

Journal Article Ecosystems · September 1, 2019 How do multiple stable states influence local and macroscale ecological patterns? Understanding how local feedbacks operate within heterogeneous coastal environments is essential to forecasting marsh persistence and loss in response to sea level rise, rive ... Full text Cite

Metabolic rhythms in flowing waters: An approach for classifying river productivity regimes

Journal Article Limnology and Oceanography · September 1, 2019 Although seasonal patterns of ecosystem productivity have been extensively described and analyzed with respect to their primary forcings in terrestrial and marine systems, comparatively little is known about these same processes in rivers. However, it is n ... Full text Cite

Climate and lawn management interact to control C₄ plant distribution in residential lawns across seven U.S. cities.

Journal Article Ecological applications : a publication of the Ecological Society of America · June 2019 In natural grasslands, C4 plant dominance increases with growing season temperatures and reflects distinct differences in plant growth rates and water use efficiencies of C3 vs. C4 photosynthetic pathways. However, in lawns ... Full text Cite

Initiation and Development of Wetlands in Southern Florida Karst Landscape Associated With Accumulation of Organic Matter and Vegetation Evolution

Journal Article Journal of Geophysical Research: Biogeosciences · June 1, 2019 Biological processes exert important controls on geomorphic evolution of karst landscapes because carbonate mineral dissolution can be augmented and spatially focused by production of CO2 and biogenic acids from organic matter (OM) decomposition. In Big Cy ... Full text Cite

Ecohydrologic feedbacks controlling sizes of cypress wetlands in a patterned karst landscape

Journal Article Earth Surface Processes and Landforms · April 1, 2019 Many landforms on Earth are profoundly influenced by biota. In particular, biota play a significant role in creating karst biogeomorphology, through biogenic CO 2 accelerating calcite weathering. In this study, we explore the ecohydrologic feedback mechani ... Full text Cite

Wetland Connectivity Thresholds and Flow Dynamics From Stage Measurements

Journal Article Water Resources Research · January 1, 2019 Depressional wetlands are dominant features in many low-gradient landscapes, where they provide water storage and exchange. Typical basin morphology enables water storage during drier periods, when surface flow paths are disconnected and exchange is limite ... Full text Cite

Residential household yard care practices along urban-exurban gradients in six climatically-diverse U.S. metropolitan areas.

Journal Article PloS one · January 2019 Residential land is expanding in the United States, and lawn now covers more area than the country's leading irrigated crop by area. Given that lawns are widespread across diverse climatic regions and there is rising concern about the environmental impacts ... Full text Cite

The metabolic regimes of 356 rivers in the United States.

Journal Article Scientific data · December 2018 A national-scale quantification of metabolic energy flow in streams and rivers can improve understanding of the temporal dynamics of in-stream activity, links between energy cycling and ecosystem services, and the effects of human activities on aquatic met ... Full text Cite

A multi-city comparison of front and backyard differences in plant species diversity and nitrogen cycling in residential landscapes

Journal Article Landscape and Urban Planning · October 1, 2018 We hypothesize that lower public visibility of residential backyards reduces households’ desire for social conformity, which alters residential land management and produces differences in ecological composition and function between front and backyards. Usi ... Full text Cite

Measuring and interpreting relationships between nutrient supply, demand, and limitation

Journal Article Freshwater Science · September 1, 2018 Stream nutrient uptake and limitation are interconnected by relationships between nutrient supply and demand. We used multiple approaches, including estimates of nutrient supply, measures of stream metabolism derived from dissolved O2 curves, and nutrient- ... Full text Cite

Artificial aquatic ecosystems

Journal Article Water (Switzerland) · August 17, 2018 As humans increasingly alter the surface geomorphology of the Earth, a multitude of artificial aquatic systems have appeared, both deliberately and accidentally. Human modifications to the hydroscape range from alteration of existing waterbodies to constru ... Full text Cite

Stream metabolism heats up

Journal Article Nature Geoscience · June 1, 2018 Higher stream temperatures as the climate warms could lead to lower ecosystem productivity and higher CO2 emissions in streams. An analysis of stream ecosystems finds that such changes will be greatest in the warmest and most productive streams. ... Full text Cite

Sediment chemistry of urban stormwater ponds and controls on denitrification

Journal Article Ecosphere · June 1, 2018 Stormwater ponds and retention basins are ubiquitous features throughout urban landscapes. These ponds are potentially important control points for nitrogen (N) removal from surface water bodies via denitrification. However, there are possible trade-offs t ... Full text Cite

Engineered headwaters can act as sources of dissolved organic matter and nitrogen to urban stream networks

Journal Article Limnology And Oceanography Letters · June 1, 2018 Improved management of urban stream water quality requires identification of sources contributing excess nutrients and organic matter. While soils and lawns are potential nonpoint sources characterized by large pools of carbon (C) and nitrogen (N), their h ... Full text Cite

The metabolic regimes of flowing waters

Journal Article Limnology and Oceanography · March 1, 2018 The processes and biomass that characterize any ecosystem are fundamentally constrained by the total amount of energy that is either fixed within or delivered across its boundaries. Ultimately, ecosystems may be understood and classified by their rates of ... Full text Cite

Homogenization of plant diversity, composition, and structure in North American urban yards:

Journal Article Ecosphere · February 1, 2018 Urban ecosystems are widely hypothesized to be more ecologically homogeneous than natural ecosystems. We argue that urban plant communities assemble from a complex mix of horticultural and regional species pools, and evaluate the homogenization hypothesis ... Full text Cite

Continental-scale homogenization of residential lawn plant communities

Journal Article Landscape and Urban Planning · September 1, 2017 Residential lawns are highly managed ecosystems that occur in urbanized landscapes across the United States. Because they are ubiquitous, lawns are good systems in which to study the potential homogenizing effects of urban land use and management together ... Full text Cite

Fertilizer management and environmental factors drive n2o and no3 losses in corn: A meta-analysis

Journal Article Soil Science Society of America Journal · September 1, 2017 Effective management of nitrogen (N) in agricultural landscapes must account for how nitrate (NO3) leaching and nitrous oxide (N2O) emissions respond to local field-scale management and to broader environmental drivers such as climate and soil. We assemble ... Full text Cite

Ecological homogenization of residential macrosystems.

Journal Article Nature ecology & evolution · June 2017 Full text Cite

Land use and topography bend and break fractal rules of water body size-distributions

Journal Article Limnology And Oceanography Letters · June 1, 2017 The size-distributions of inland water bodies (WB) within different regions often poorly conform to geophysically based theoretical models (power-law: y = axβ); however, the causes of these deviations remain unknown. Therefore, we compared WB abundance and ... Full text Cite

Landscape and Regional Stream Ecology

Chapter · July 21, 2016 Due to the directional flow of water, the study of streams is an inherently spatial undertaking. Since early in its emergence, stream research has emphasized the connection between the ecology of channels and the valleys they drain, as well as the connecti ... Full text Cite

Plant nitrogen concentration and isotopic composition in residential lawns across seven US cities.

Journal Article Oecologia · May 2016 Human drivers are often proposed to be stronger than biophysical drivers in influencing ecosystem structure and function in highly urbanized areas. In residential land cover, private yards are influenced by individual homeowner preferences and actions whil ... Full text Cite

Ecosystem services in managing residential landscapes: priorities, value dimensions, and cross-regional patterns

Journal Article Urban Ecosystems · March 1, 2016 Although ecosystem services have been intensively examined in certain domains (e.g., forests and wetlands), little research has assessed ecosystem services for the most dominant landscape type in urban ecosystems—namely, residential yards. In this paper, w ... Full text Cite

Satisfaction, water and fertilizer use in the American residential macrosystem

Journal Article Environmental Research Letters · February 29, 2016 Residential yards across the US look remarkably similar despite marked variation in climate and soil, yet the drivers of this homogenization are unknown. Telephone surveys of fertilizer and irrigation use and satisfaction with the natural environment, and ... Full text Cite

Convergence of microclimate in residential landscapes across diverse cities in the United States

Journal Article Landscape Ecology · January 1, 2016 Context: The urban heat island (UHI) is a well-documented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Re ... Full text Cite

Using Tribal Fishing Rights as Leverage to Restore Salmon Populations in the Columbia River Basin

Conference Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference · January 1, 2016 Link to item Cite

Designer Ecosystems: Incorporating Design Approaches into Applied Ecology

Chapter · November 4, 2015 To satisfy a growing population, much of Earth's surface has been designed to suit humanity's needs. Although these ecosystem designs have improved human welfare, they have also produced significant negative environmental impacts, which applied ecology as ... Full text Cite

Nutrient limitation and physiology mediate the fine-scale (de)coupling of biogeochemical cycles.

Journal Article The American naturalist · September 2014 Nutrients in the environment are coupled over broad timescales (days to seasons) when organisms add or withdraw multiple nutrients simultaneously and in ratios that are roughly constant. But at finer timescales (seconds to days), nutrients become decoupled ... Full text Cite

Morphological characteristics of urban water bodies: mechanisms of change and implications for ecosystem function.

Journal Article Ecological applications : a publication of the Ecological Society of America · July 2014 The size, shape, and connectivity of water bodies (lakes, ponds, and wetlands) can have important effects on ecological communities and ecosystem processes, but how these characteristics are influenced by land use and land cover change over broad spatial s ... Full text Open Access Cite

Assessing the homogenization of urban land management with an application to US residential lawn care.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · March 2014 Changes in land use, land cover, and land management present some of the greatest potential global environmental challenges of the 21st century. Urbanization, one of the principal drivers of these transformations, is commonly thought to be generating land ... Full text Open Access Cite

Ecological homogenization of urban USA

Journal Article Frontiers in Ecology and the Environment · February 1, 2014 A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential lots, commercial areas, and aquatic features. ... Full text Open Access Cite

Macrosystems ecology: Understanding ecological patterns and processes at continental scales

Journal Article Frontiers in Ecology and the Environment · February 1, 2014 Macrosystems ecology is the study of diverse ecological phenomena at the scale of regions to continents and their interactions with phenomena at other scales. This emerging subdiscipline addresses ecological questions and environmental problems at these br ... Full text Open Access Cite

Nutrient flux, uptake, and autotrophic limitation in streams and rivers

Journal Article Freshwater Science · January 1, 2014 Assessments of biotic nutrient limitation in aquatic ecosystems typically rely on concentrations and ratios of potentially limiting nutrients. While successful in lakes, this approach has been less effective in streams, which often are dominated by benthic ... Full text Cite

Diel phosphorus variation and the stoichiometry of ecosystem metabolism in a large spring-fed river

Journal Article Ecological Monographs · May 1, 2013 Elemental cycles are coupled directly and indirectly to ecosystem metabolism at multiple time scales. Understanding coupling in lotic ecosystems has recently advanced through simultaneous high-frequency measurements of multiple solutes. Using hourly in sit ... Full text Cite

On the multiple ecological roles of water in river networks

Journal Article Ecosphere · February 6, 2013 The distribution and movement of water can influence the state and dynamics of terrestrial and aquatic ecosystems through a diversity of mechanisms. These mechanisms can be organized into three general categories wherein water acts as (1) a resource or hab ... Full text Open Access Cite

Sustainability and Biodiversity

Chapter · January 1, 2013 Extraordinary rates of biodiversity loss, coupled with rising human population and consumption rates, threaten the sustainability of Earth's life support systems. An inclusive wealth framework that considers the current and future stocks and flows of human ... Full text Cite

Discharge competence and pattern formation in peatlands: a meta-ecosystem model of the Everglades ridge-slough landscape.

Journal Article PloS one · January 2013 Regular landscape patterning arises from spatially-dependent feedbacks, and can undergo catastrophic loss in response to changing landscape drivers. The central Everglades (Florida, USA) historically exhibited regular, linear, flow-parallel orientation of ... Full text Open Access Cite

Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer

Journal Article Biogeosciences · May 22, 2012 Aquifer denitrification is among the most poorly constrained fluxes in global and regional nitrogen budgets. The few direct measurements of denitrification in groundwaters provide limited information about its spatial and temporal variability, particularly ... Full text Open Access Cite

Inference of riverine nitrogen processing from longitudinal and diel variation in dual nitrate isotopes

Journal Article Journal of Geophysical Research: Biogeosciences · March 1, 2012 Longitudinal and diel measurements of dual isotope composition (δ15N and δ18O) in nitrate (NO3-N) were made in the Ichetucknee River, a large (∼8m3 s -1), entirely spring-fed river in North Florida, to ... Full text Open Access Cite

Plantâmicrobe interactions and nitrogen dynamics during wetland establishment in a desert stream

Journal Article Biogeochemistry. · February 2012 In late-successional steady state ecosystems, plants and microbes compete for nutrients and nutrient retention efficiency is expected to decline when inputs exceed biotic demand. In carbon (C)-poor environments typical of early primary succession, nitrogen ... Full text Cite

Reciprocal biotic control on hydrology, nutrient gradients, and landform in the greater everglades

Journal Article Critical Reviews in Environmental Science and Technology · February 25, 2011 Restoration can be viewed as the process of reestablishing both exogenous drivers and internal feedbacks that maintain ecosystems in a desirable state. Correcting exogenous and abiotic drivers is clearly necessary, but may be insufficient to achieve desire ... Full text Cite

QBIC, an interdisciplinary and quantitative biological sciences curriculum: Concept to implementation

Journal Article Journal of Science Education · January 1, 2011 QBIC (Quantifying Biology in the Classroom) is a reformed four-year (freshmansenior) program within the Biological Sciences Department at Florida International University. QBIC was implemented with a cohort of 23 freshmen fall 2007, a second cohort of fres ... Cite

Hydrologic Modification and the Loss of Self-organized Patterning in the Ridge-Slough Mosaic of the Everglades

Journal Article Ecosystems. · September 2010 The ridge-slough landscape of the Everglades (Florida, USA), is characterized by elevated ridges dominated by sawgrass (Cladium jamaicense) interspersed among deeper sloughs dominated by floating, submerged and emergent macrophytes and calcareous periphyto ... Full text Cite

Algal blooms and the nitrogen-enrichment hypothesis in Florida springs: evidence, alternatives, and adaptive management.

Journal Article Ecological applications : a publication of the Ecological Society of America · April 2010 Contradictions between system-specific evidence and broader paradigms to explain ecosystem behavior present a challenge for natural resource management. In Florida (U.S.A.) springs, increasing nitrate (NO3-) concentrations have been implicated as the cause ... Full text Open Access Cite

Direct and indirect coupling of primary production and diel nitrate dynamics in a subtropical spring-fed river

Journal Article Limnology and Oceanography · March 1, 2010 We used high-frequency in situ measurements of nitrate (NO3-) and dissolved oxygen (DO) from the springfed Ichetucknee River, Florida, to derive multiple independent estimates of assimilatory nitrogen (N) demand, and to evaluate the short-term dependence o ... Full text Open Access Cite

Hydrologie and biotic influences on nitrate removal in a subtropical spring-fed river

Journal Article Limnology and Oceanography · January 1, 2010 We use a long-term chemical and hydrologic record in combination with longitudinal sampling and highfrequency nitrate (NO3-) measurements from in situ sensors to describe temporal and spatial patterns of nitrogen (N) inputs and removal in the spring-fed Ic ... Full text Open Access Cite

Consequences of a biogeomorphic regime shift for the hyporheic zone of a Sonoran Desert stream

Journal Article Freshwater Biology · October 1, 2008 1. Feedbacks between vegetation and geomorphic processes can generate alternative stable states and other nonlinear behaviours in ecological systems, but the consequences of these biogeomorphic interactions for other ecosystem processes are poorly understo ... Full text Cite

Unintended consequences of urbanization for aquatic ecosystems: A case study from the Arizona desert

Journal Article BioScience · September 1, 2008 Many changes wrought during the construction of "designer ecosystems" are intended to ensure - and often succeed in ensuring - that a city can provide ecosystem goods and services; but other changes have unintended impacts on the ecology of the city, impai ... Full text Open Access Cite

Wetlands as an alternative stable state in desert streams.

Journal Article Ecology · May 2008 Historically, desert drainages of the American southwest supported productive riverine wetlands (ciénegas). Region-wide erosion of ciénegas during the late 19th and early 20th century dramatically reduced the abundance of these ecosystems, but recent reest ... Full text Open Access Cite

Functional ecomorphology: Feedbacks between form and function in fluvial landscape ecosystems

Journal Article Geomorphology · September 1, 2007 The relationship between form and function has been a central organizing principle in biology throughout its history as a formal science. This concept has been relevant from molecules to organisms but loses meaning at population and community levels where ... Full text Cite

Riparian zones increase regional species richness by harboring different, not more, species

Journal Article Ecology · January 1, 2005 Riparian zones are habitats of critical conservation concern worldwide, as they are known to filter agricultural contaminants, buffer landscapes against erosion, and provide habitat for high numbers of species. Here we test the generality of the notion tha ... Full text Open Access Cite

Nutrient mobilization and processing in Sonoran desert riparian soils following artificial re-wetting

Journal Article Biogeochemistry · August 1, 2004 Research in river-floodplain systems has emphasized the importance of nutrient delivery by floodwaters, but the mechanisms by which floods make nutrients available are rarely evaluated. Using a laboratory re-wetting experiment, we evaluated the alternative ... Full text Cite

Effects of urbanization on nutrient biogeochemistry of aridland streams

Chapter · January 1, 2004 Land-use and land-cover change affect the biogeochemistry of stream ecosystems in numerous ways, both direct and indirect. Changes result from hydrologic modifications, including direct alterations of flow regimes and hydrologic flowpaths and indirect chan ... Full text Cite

Horizons in stream biogeochemistry: Flowpaths to progress

Journal Article Ecology · January 1, 2004 Over the past 50 years, conceptual developments in stream ecology and ecosystem ecology have converged, thanks to biogeochemistry and the recognition that in situ processing on one hand and spatial translation of materials, processes, and influence along f ... Full text Cite

The influence of dissolved nutrients and particulate organic matter quality on microbial respiration and biomass in a forest stream

Journal Article Freshwater Biology · November 1, 2003 1. Although dissolved nutrients and the quality of particulate organic matter (POM) influence microbial processes in aquatic systems, these factors have rarely been considered simultaneously. We manipulated dissolved nutrient concentrations and POM type in ... Full text Cite

A RURAL SOCIOLOGISTS PERSPECTIVE

Conference SURGEON GENERAL'S CONFERENCE ON AGRICULTURAL SAFETY AND HEALTH · January 1, 1992 Link to item Cite

Efficiency Considerations in the Social Welfare Agency

Journal Article Administration in Social Work · April 5, 1991 Full text Cite