David M. Iwaniec
Arizona State University
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Featured researches published by David M. Iwaniec.
Sustainability Science | 2014
Arnim Wiek; David M. Iwaniec
Envisioning how a desirable future might look is a long-standing effort in human evolution and social change. Utopian thought and visions provide direction for actions and behavior; more so, they create identity and community. Accordingly, the discourse on sustainability and sustainable development has recognized that positive visions about our societies’ future are an influential, if not indispensable, stimulus for change. Visioning is, thus, considered a key method in sustainability research and problem solving, for instance, in transformational sustainability science or in planning for urban sustainability. Yet, quality criteria for sustainability visions and guidelines on how to rigorously craft such visions are scattered over different strands of the literature and some are insufficiently developed. The goal of this article is to review and synthesize such quality criteria and design guidelines to inform sustainability visioning methodology. The review provides a concise reference framework for sustainability students, researchers, and professionals on how to enhance their sustainability visioning practices.
Hydrobiologia | 2006
Daniel L. Childers; David M. Iwaniec; Damon Rondeau; Gustavo Rubio; Emilie Verdon; Christopher J. Madden
Aboveground net primary production (ANPP) by the dominant macrophyte and plant community composition are related to the changing hydrologic environment and to salinity in the southern Everglades, FL, USA. We present a new non-destructive ANPP technique that is applicable to any continuously growing herbaceous system. Data from 16 sites, collected from 1998 to 2004, were used to investigate how hydrology and salinity controlled sawgrass (Cladium jamaicense Crantz.) ANPP. Sawgrass live biomass showed little seasonal variation and annual means ranged from 89 to 639 gdw m−2. Mortality rates were 20–35% of live biomass per 2 month sampling interval, for biomass turnover rates of 1.3–2.5 per year. Production by C. jamaicense was manifest primarily as biomass turnover, not as biomass accumulation. Rates typically ranged from 300 to 750 gdw m−2 year−1, but exceeded 1000 gdw m−2 year−1 at one site and were as high as 750 gdw m−2 year−1 at estuarine ecotone sites. Production was negatively related to mean annual water depth, hydroperiod, and to a variable combining the two (depth-days). As water depths and hydroperiods increased in our southern Everglades study area, sawgrass ANPP declined. Because a primary restoration goal is to increase water depths and hydroperiods for some regions of the Everglades, we investigated how the plant community responded to this decline in sawgrass ANPP. Spikerush (Eleocharis sp.) was the next most prominent component of this community at our sites, and 39% of the variability in sawgrass ANPP was explained by a negative relationship with mean annual water depth, hydroperiod, and Eleocharis sp. density the following year. Sawgrass ANPP at estuarine ecotone sites responded negatively to salinity, and rates of production were slow to recover after high salinity years. Our results suggest that ecologists, managers, and the public should not necessarily interpret a decline in sawgrass that may result from hydrologic restoration as a negative phenomenon.
Hydrobiologia | 2006
David M. Iwaniec; Daniel L. Childers; Damon Rondeau; Christopher J. Madden; Colin J. Saunders
Everglades periphyton mats are tightly-coupled autotrophic (algae and cyanobacteria) and heterotrophic (eubacteria, fungi and microinvertebrates) microbial assemblages. We investigated the effect of water column total phosphorus and nitrogen concentrations, water depth and hydroperiod on periphyton of net production, respiration, nutrient content, and biomass. Our study sites were located along four transects that extended southward with freshwater sheetflow through sawgrass-dominated marsh. The water source for two of the transects were canal-driven and anchored at canal inputs. The two other transects were rain-driven (ombrotrophic) and began in sawgrass-dominated marsh. Periphyton dynamics were examined for upstream and downstream effects within and across the four transects. Although all study sites were characterized as short hydroperiod and phosphorus-limited oligotrophic, they represent gradients of hydrologic regime, water source and water quality of the southern Everglades. Average periphyton net production of 1.08 mg C AFDW−1 h−1 and periphyton whole system respiration of 0.38 mg C AFDW−1 h−1 rates were net autotrophic. Biomass was generally highest at ombrotrophic sites and sites downstream of canal inputs. Mean biomass over all our study sites was high, 1517.30 g AFDW m−2. Periphyton was phosphorus-limited. Average periphyton total phosphorus content was 137.15 μg P g−1 and average periphyton total N:P ratio was 192:1. Periphyton N:P was a sensitive indicator of water source. Even at extremely low mean water total phosphorus concentrations ( ≤ 0.21 μmol l−1), we found canal source effects on periphyton dynamics at sites adjacent to canal inputs, but not downstream of inflows. These canal source effects were most pronounced at the onset of wet season with initial rewetting. Spatial and temporal variability in periphyton dynamics could not solely be ascribed to water quality, but was often associated with both hydrology and water source.
Ecological Applications | 2012
Geneviève S. Metson; Rebecca L. Hale; David M. Iwaniec; Elizabeth M. Cook; Jessica R. Corman; Christopher S. Galletti; Daniel L. Childers
As urban environments dominate the landscape, we need to examine how limiting nutrients such as phosphorus (P) cycle in these novel ecosystems. Sustainable management of P resources is necessary to ensure global food security and to minimize freshwater pollution. We used a spatially explicit budget to quantify the pools and fluxes of P in the Greater Phoenix Area in Arizona, USA, using the boundaries of the Central Arizona-Phoenix Long-Term Ecological Research site. Inputs were dominated by direct imports of food and fertilizer for local agriculture, while most outputs were small, including water, crops, and material destined for recycling. Internally, fluxes were dominated by transfers of food and feed from local agriculture and the recycling of human and animal excretion. Spatial correction of P dynamics across the city showed that human density and associated infrastructure, especially asphalt, dominated the distribution of P pools across the landscape. Phosphorus fluxes were dominated by agricultural production, with agricultural soils accumulating P. Human features (infrastructure, technology, and waste management decisions) and biophysical characteristics (soil properties, water fluxes, and storage) mediated P dynamics in Phoenix. P cycling was most notably affected by water management practices that conserve and recycle water, preventing the loss of waterborne P from the ecosystem. P is not intentionally managed, and as a result, changes in land use and demographics, particularly increased urbanization and declining agriculture, may lead to increased losses of P from this system. We suggest that city managers should minimize cross-boundary fluxes of P to the city. Reduced P fluxes may be accomplished through more efficient recycling of waste, therefore decreasing dependence on external nonrenewable P resources and minimizing aquatic pollution. Our spatial approach and consideration of both pools and fluxes across a heterogeneous urban ecosystem increases the utility of nutrient budgets for city managers. Our budget explicitly links processes that affect P cycling across space with the management of other resources (e.g., water). A holistic management strategy that deliberately couples the management of P and other resources should be a priority for cities in achieving urban sustainability.
Planning Practice and Research | 2014
David M. Iwaniec; Arnim Wiek
Sustainability visioning—creating descriptions of sustainable and desirable future states—has become a prominent tool in urban planning to guide how cities are structured, how they function, and how they are governed. In this article, we present the application of a sustainability visioning approach (SPARC) in support of the City of Phoenixs General Plan Update. The study strove to overcome deficits in current visioning practices, including sufficiently accounting for systems relationships, conflicting values, sustainability principles and stakeholder input; combining public participation with capacity building; and linking creative with analytical activities. We discuss and draw conclusions from this study on how to improve professional and civic capacity for visioning as well as how to bridge the gap between advanced planning practice and research.
BioScience | 2017
Carena J. van Riper; Adam C. Landon; Sarah Kidd; Patrick Bitterman; Lee A. Fitzgerald; Elise F. Granek; Sonia N. Ibarra; David M. Iwaniec; Christopher M. Raymond; David Toledo
Abstract Ecosystem‐services scholarship has largely focused on monetary valuation and the material contributions of ecosystems to human well‐being. Increasingly, research is calling for a deeper understanding of how less tangible, nonmaterial values shape management and stakeholder decisions. We propose a framework that characterizes a suite of sociocultural phenomena rooted in key social science disciplines that are currently underrepresented in the ecosystem‐services literature. The results from three example studies are presented to demonstrate how the tenets of this conceptual model can be applied in practice. We consider the findings from these studies in light of three priorities for future research: (1) complexities in individual and social functioning, (2) the salience and specificity of the perceived benefits of nature, and (3) distinctions among value concepts. We also pose a series of questions to stimulate reflection on how ecosystem‐services research can adopt more pluralistic viewpoints that accommodate different forms of knowledge and its acquisition.
Archive | 2016
Dana Cordell; Geneviève S. Metson; David M. Iwaniec; Thuy T. Bui; Daniel L. Childers; Nguyet Dao; Huyen T.T. Dang; J. Davidson; Brent Jacobs; Save Kumwenda; Tracy Morse; Viet Anh Nguyen; Bernard Thole; Elizabeth A. Tilley
Transdisciplinary Research and Practice for Sustainability Outcomes examines the role of transdisciplinarity in the transformations needed for a sustainable world. After an historical overview of transdisciplinarity, Part 1 focuses on tools and frameworks to achieve sustainability outcomes in practice and Part 2 consolidates work by a number of scholars on supporting transdisciplinary researchers and practitioners.Part 3 is a series of case studies including several international examples that demonstrate the challenges and rewards of transdisciplinary work. The concluding chapter proposes a future research pathway for understanding the human factors that underpin successful transdisciplinary research.
Hydrobiologia | 2006
Sharon M.L. Ewe; Evelyn E. Gaiser; Daniel L. Childers; David M. Iwaniec; Victor H. Rivera-Monroy; Robert R. Twilley
Environmental Science & Policy | 2015
Geneviève S. Metson; David M. Iwaniec; Lawrence A. Baker; Elena M. Bennett; Daniel L. Childers; Dana Cordell; Nancy B. Grimm; J. Morgan Grove; Daniel A. Nidzgorski; S White
Sustainability | 2015
Melissa R. McHale; Steward T. A. Pickett; Olga Barbosa; David Bunn; Mary L. Cadenasso; Daniel L. Childers; Meredith Gartin; George R. Hess; David M. Iwaniec; Timon McPhearson; M. Nils Peterson; Alexandria K. Poole; Louie Rivers; Shade T. Shutters; Weiqi Zhou