Irena F. Creed

Bio: Irena F. Creed is an academic researcher from University of Saskatchewan. The author has contributed to research in topics: Wetland & Climate change. The author has an hindex of 42, co-authored 195 publications receiving 7969 citations. Previous affiliations of Irena F. Creed include University of Western Ontario & University of Toronto.

Emerging threats and persistent conservation challenges for freshwater biodiversity

Abstract: In the 12 years since Dudgeon et al. (2006) reviewed major pressures on freshwater ecosystems, the biodiversity crisis in the world’s lakes, reservoirs, rivers, streams and wetlands has deepened. While lakes, reservoirs and rivers cover only 2.3% of the Earth’s surface, these ecosystems host at least 9.5% of the Earth’s described animal species. Furthermore, using the World Wide Fund for Nature’s Living Planet Index, freshwater population declines (83% between 1970 and 2014) continue to outpace contemporaneous declines in marine or terrestrial systems. The Anthropocene has brought multiple new and varied threats that disproportionately impact freshwater systems. We document 12 emerging threats to freshwater biodiversity that are either entirely new since 2006 or have since intensified: (i) changing climates; (ii) e-commerce and invasions; (iii) infectious diseases; (iv) harmful algal blooms; (v) expanding hydropower; (vi) emerging contaminants; (vii) engineered nanomaterials; (viii) microplastic pollution; (ix) light and noise; (x) freshwater salinisation; (xi) declining calcium; and (xii) cumulative stressors. Effects are evidenced for amphibians, fishes, invertebrates, microbes, plants, turtles and waterbirds, with potential for ecosystem-level changes through bottom-up and top-down processes. In our highly uncertain future, the net effects of these threats raise serious concerns for freshwater ecosystems. However, we also highlight opportunities for conservation gains as a result of novel management tools (e.g. environmental flows, environmental DNA) and specific conservation-oriented actions (e.g. dam removal, habitat protection policies,managed relocation of species) that have been met with varying levels of success.Moving forward, we advocate hybrid approaches that manage fresh waters as crucial ecosystems for human life support as well as essential hotspots of biodiversity and ecological function. Efforts to reverse global trends in freshwater degradation now depend on bridging an immense gap between the aspirations of conservation biologists and the accelerating rate of species endangerment.

Trees, forests and water : Cool insights for a hot world

Abstract: Forest-driven water and energy cycles are poorly integrated into regional, national, continental and global decision-making on climate change adaptation, mitigation, land use and water management. This constrains humanity's ability to protect our planet's climate and life-sustaining functions. The substantial body of research we review reveals that forest, water and energy interactions provide the foundations for carbon storage, for cooling terrestrial surfaces and for distributing water resources. Forests and trees must be recognized as prime regulators within the water, energy and carbon cycles. If these functions are ignored, planners will be unable to assess, adapt to or mitigate the impacts of changing land cover and climate. Our call to action targets a reversal of paradigms, from a carbon-centric model to one that treats the hydrologic and climate-cooling effects of trees and forests as the first order of priority. For reasons of sustainability, carbon storage must remain a secondary, though valuable, by-product. The effects of tree cover on climate at local, regional and continental scales offer benefits that demand wider recognition. The forest- and tree-centered research insights we review and analyze provide a knowledge-base for improving plans, policies and actions. Our understanding of how trees and forests influence water, energy and carbon cycles has important implications, both for the structure of planning, management and governance institutions, as well as for how trees and forests might be used to improve sustainability, adaptation and mitigation efforts.

Regulation of Nitrate‐N Release from Temperate Forests: A Test of the N Flushing Hypothesis

Abstract: During the past decade, significant spatial and temporal variability in the release of nitrate-nitrogen (N) from catchments in a sugar maple forest in central Ontario was observed. To explain this variability, we tested the flushing hypothesis [Hornberger et al., 1994], where, when the soil saturation deficit is high, N accumulates in the upper layers of the soil and, as the soil saturation deficit decreases, the formation of a saturated subsurface layer flushes N from the upper layers of the soil into the stream. We used the Regional Hydro-Ecological Simulation System to simulate water, carbon, and N dynamics. A N flushing index was modeled as S/S30, the ratio of the current day saturation deficit to the previous 30-day average saturation deficit. A N source index was modeled as the ratio of N supply/demand. The relationship between the simulated N indices and the observed release of N indicated two mechanisms for the release of N from catchments: (1) a N flushing mechanism, where the N-enriched upper layer of the soil is flushed, after a period of low demand for N by the forest (e.g., during spring snowmelt and autumn stormflow, the water table rising into previously unsaturated parts of a N-enriched soil profile) or after a period of high demand for N by the forest (e.g., during summer droughts, the water table rising into previously saturated parts of a N-impoverished soil profile following a period of enhanced rates of nitrification); and (2) a N draining mechanism, where spring snowmelt recharge of the groundwater translocates N from the upper layer of the soil into deeper hydrological flow pathways that are released slowly over the year.

A framework for broad‐scale classification of hydrologic response units on the Boreal Plain: is topography the last thing to consider?

Abstract: K. Devito,1* I. Creed,2 T. Gan,3 C. Mendoza,4 R. Petrone,5 U. Silins6 and B. Smerdon4 1 University of Alberta, Department of Biological Sciences, Edmonton, Alberta T6G 2E9, Canada 2 University of Western Ontario, Department of Biology, London, Ontario, Canada 3 University of Alberta, Civil and Environmental Engineering, Edmonton, Alberta T6G 2W2, Canada 4 University of Alberta, Department of Earth & Atmospheric Sciences, Edmonton, Alberta T6G 2E3, Canada 5 Wilfrid Laurier University, Department of Geography and Environmental Studies, Waterloo, Ontario, Canada 6 University of Alberta, Department of Renewable Resources, Edmonton, Alberta T6G 2H1, Canada

Export of nitrogen from catchments within a temperate forest: Evidence for a unifying mechanism regulated by variable source area dynamics

Abstract: Considerable variation in the export of dissolved inorganic nitrogen (DIN) and dissolved organic nitrogen (DON) was observed among catchments located within an old- growth sugar maple forest in central Ontario. Although discharge was a strong predictor of N-export, rates of export were variable for each catchment, ranging from 250% to 150% from the catchment-average response for DIN and 225% to 125% from the catchment-average response for DON. Among the catchments, a unifying flushing behavior was apparent for NO3 -N, the dominant form of DIN in the discharge waters, providing a basis for explaining the variation in the export of DIN. Flushing occurs when a water table rises to the soil surface with subsequent mobilization of nutrients stored near or at the soil surface to surface waters. Catchment-specific flushing behaviors were captured in "flushing" characteristic time constants, defined as the time interval required for a decline in N concentrations in discharge waters to e 21 (37%) of their initial concentration. Variation in flushing behavior was linked to variation in N export; catchments with short flushing times (interpreted as catchments with source areas that are less variable) were observed to export less N than catchments with long flushing times (source areas that are more variable). A hypothesis was formulated in which catchment topography and its influence on variable source area dynamics accounts for variation in flushing behavior, hence variation in the export of NO3 -N among the catchments. The implication of this hypothesis is that to predict accurately the export of NO3 -N from catchments within a landscape, we need first to consider the influence of the topographic complexity of the catchments. Our understanding of the mechanisms of processing and export of DON is not sufficient for accurate prediction at this point, highlighting the need for additional research on DON.

Nudge: Improving Decisions about Health, Wealth, and Happiness

Abstract: NUDGE: IMPROVING DECISIONS ABOUT HEALTH, WEALTH, AND HAPPINESS by Richard H. Thaler and Cass R. Sunstein Penguin Books, 2009, 312 pp, ISBN 978-0-14-311526-7This book is best described formally as a general explanation of and advocacy for libertarian paternalism, a term coined by the authors in earlier publications. Informally, it is about how leaders, systems, organizations, and governments can nudge people to do the things the nudgers want and need done for the betterment of the nudgees, or of society. It is paternalism in the sense that "it is legitimate for choice architects to try to influence people's behavior in order to make their lives longer, healthier, and better", (p. 5) It is libertarian in that "people should be free to do what they like - and to opt out of undesirable arrangements if they want to do so", (p. 5) The built-in possibility of opting out or making a different choice preserves freedom of choice even though people's behavior has been influenced by the nature of the presentation of the information or by the structure of the decisionmaking system. I had never heard of libertarian paternalism before reading this book, and I now find it fascinating.Written for a general audience, this book contains mostly social and behavioral science theory and models, but there is considerable discussion of structure and process that has roots in mathematical and quantitative modeling. One of the main applications of this social system is economic choice in investing, selecting and purchasing products and services, systems of taxes, banking (mortgages, borrowing, savings), and retirement systems. Other quantitative social choice systems discussed include environmental effects, health care plans, gambling, and organ donations. Softer issues that are also subject to a nudge-based approach are marriage, education, eating, drinking, smoking, influence, spread of information, and politics. There is something in this book for everyone.The basis for this libertarian paternalism concept is in the social theory called "science of choice", the study of the design and implementation of influence systems on various kinds of people. The terms Econs and Humans, are used to refer to people with either considerable or little rational decision-making talent, respectively. The various libertarian paternalism concepts and systems presented are tested and compared in light of these two types of people. Two foundational issues that this book has in common with another book, Network of Echoes: Imitation, Innovation and Invisible Leaders, that was also reviewed for this issue of the Journal are that 1 ) there are two modes of thinking (or components of the brain) - an automatic (intuitive) process and a reflective (rational) process and 2) the need for conformity and the desire for imitation are powerful forces in human behavior. …

Mitigation and Adaptation Strategies for Global Change

Abstract: ▶ Addresses a wide range of timely environment, economic and energy topics ▶ A forum to review, analyze and stimulate the development, testing and implementation of mitigation and adaptation strategies at regional, national and global scales ▶ Contributes to real-time policy analysis and development as national and international policies and agreements are discussed and promulgated ▶ 94% of authors who answered a survey reported that they would definitely publish or probably publish in the journal again

Image Processing

Abstract: MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.

Biogeochemical Hot Spots and Hot Moments at the Interface of Terrestrial and Aquatic Ecosystems

Abstract: Rates and reactions of biogeochemical processes vary in space and time to produce both hot spots and hot moments of elemental cycling. We define biogeochemical hot spots as patches that show disproportionately high reaction rates relative to the surrounding matrix, whereas hot moments are defined as short periods of time that exhibit disproportionately high reaction rates relative to longer intervening time periods. As has been appreciated by ecologists for decades, hot spot and hot moment activity is often enhanced at terrestrial-aquatic interfaces. Using examples from the carbon (C) and nitrogen (N) cycles, we show that hot spots occur where hydrological flowpaths converge with substrates or other flowpaths containing complementary or missing reactants. Hot moments occur when episodic hydrological flowpaths reactivate and/or mobilize accumulated reactants. By focusing on the delivery of specific missing reactants via hydrologic flowpaths, we can forge a better mechanistic understanding of the factors that create hot spots and hot moments. Such a mechanistic understanding is necessary so that biogeochemical hot spots can be identified at broader spatiotemporal scales and factored into quantitative models. We specifically recommend that resource managers incorporate both natural and artificially created biogeochemical hot spots into their plans for water quality management. Finally, we emphasize the needs for further research to assess the potential importance of hot spot and hot moment phenomena in the cycling of different bioactive elements, improve our ability to predict their occurrence, assess their importance in landscape biogeochemistry, and evaluate their utility as tools for resource management.

Of Theory and Practice

Abstract: Much has been written about theory and practice in the law, and the tension between practitioners and theorists. Judges do not cite theoretical articles often; they rarely "apply" theories to particular cases. These arguments are not revisited. Instead the Essay explores the working and interaction of theory and practice, practitioners and theorists. The Essay starts with a story about solving a legal issue using our intellectual tools - theory, practice, and their progenies: experience and "gut." Next the Essay elaborates on the nature of theory, practice, experience and "gut." The third part of the Essay discusses theories that are helpful to practitioners and those that are less helpful. The Essay concludes that practitioners theorize, and theorists practice. They use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ. Theory, practice, experience and "gut" help us think, remember, decide and create. They complement each other like the two sides of the same coin: distinct but inseparable.