John E. Petersen

Dormitory residents reduce electricity consumption when exposed to real‐time visual feedback and incentives

Purpose – In residential buildings, personal choices influence electricity and water consumption. Prior studies indicate that information feedback can stimulate resource conservation. College dormitories provide an excellent venue for controlled study of the effects of feedback. The goal of this study is to assess how different resolutions of socio‐technical feedback, combined with incentives, encourage students to conserve resources.Design/methodology/approach – An automated data monitoring system was developed that provided dormitory residents with real‐time web‐based feedback on energy and water use in two “high resolution” dormitories. In contrast, utility meters were manually read for 20 “low‐resolution” dormitories, and data were provided to residents once per week. For both groups, resource use was monitored during a baseline period and during a two week “dorm energy competition” during which feedback, education and conservation incentives were provided.Findings – Overall, the introduction of feedb...

Scaling relations in experimental ecology

Figures Tables Contributors Preface I. Background 1. Scale Dependence and the Problem of Extrapolation: Implications for Experimental & Natural Coastal Ecosystems, by W. Michael Kemp, John E. Petersen, Robert H. Gardner II. Scaling Theory 2. Understanding the Problem of Scale in Experimental Ecology, by John A. Wiens 3. The Nature of the Scale Issue in Experimentation, by Timothy F. H. Allen 4. Spatial Allometry: Theory & Application to Experimental and Natural Aquatic Ecosystems, by David C. Schneider III. Scaling Mesocosms to Nature 5. Getting it Right and Wrong: Extrapolations Across Experimental Scales, by Michael L. Pace 6. Some Reluctant Ruminations on Scales (and Claws and Teeth) in Marine Mesocosms, by Scott Nixon 7. Evaluating and Modeling Foraging Performance of Planktivorous & Picivorous Fish: Effects of Containment and Issues of Scale, by Michael R. Heath & Edward D. Houde 8. Experimental Validity & Ecological Scale as Criteria for Evaluating Research Programs, by Shahid Naeem IV. Scale & Experiment in Different Ecosystems 9. Scaling Issues in Experimental Ecology: Fresh Water Systems, by Thomas M. Frost, Robert E. Ulanowicz, Steve C. Blomenshine, Timothy F. H. Allen 10. Terrestrial Perspectives on Issues of Scale in Experimental Ecology, by Anthony W. King, Robert H. Gardner, Colleen A. Hatfield, Shahid Naeem, John E. P 11. Issues of Scale in Land-Margin Ecosystems, by Walter R. Boynton, James D. Hagy, and Denise L. Breitburg 12. Scaling Issues in Marine Experimental Ecosystems: The Role of Patchiness, by David L. Scheurer, David C. Schneider, and Lawrence P. Sanford Index

SCALING AQUATIC PRIMARY PRODUCTIVITY: EXPERIMENTS UNDER NUTRIENT‐ AND LIGHT‐LIMITED CONDITIONS

To explore the interactive effect of physical dimension and nutrient conditions on primary productivity, experimental planktonic–benthic ecosystems were initiated in different-sized cylindrical containers scaled in two ways. One series of experimental ecosystems was scaled for a constant depth (1.0 m) as volume was increased from 0.1 to 1.0 to 10 m3. The other series was scaled for a constant shape (radius/depth = 0.56) across an identical range of volumes. Triplicate systems of each size and shape were housed in a temperature-controlled room illuminated with fluorescent and incandescent lights, and mixed by means of large, slow-moving impellers. All experimental ecosystems received an exchange of filtered estuarine water (10%/d). Nutrient concentrations, and ecosystem primary productivity and respiration, were traced over time during spring, summer, and fall experiments. During the nutrient-rich spring experiment, systems in the constant-shape series exhibited similar gross primary productivity (GPP) whe...

Dimensional approaches to scaling experimental ecosystems: designing mousetraps to catch elephants.

Enclosed experimental ecosystems (mesocosms) are small relative to their natural counterparts, are typically operated for short durations relative to the timescales of a number of important ecological processes, and also often have reduced biological and physical complexity relative to nature. These reductions in time, space, and complexity scales have been cited as sources of unrealistic ecological behavior within mesocosms and raise questions about extrapolating results from mesocosms to nature. Dimensional analysis, a technique widely used by engineers to create scale models, uses compensatory distortion as a means of maintaining dynamic similarity in properties and relationships of interest. Although biological parameters are generally less controllable than physical ones, a variety of dimensional approaches can be taken to maintain such key ecological properties as effective habitat size, environmental variability, vertical and horizontal gradients, interactions among habitats, and control of experimental artifacts. To date, application of dimensional approaches to mesocosm design has been largely intuitive and idiosyncratic. We argue that a more explicit, systematic, and quantitative approach will increase realism and may also provide a critical means of developing, testing, and advancing our understanding of scaling relationships in nature.

Dimensional approaches to designing better experimental ecosystems: a practitioners guide with examples

Enclosed, experimental ecosystems (“mesocosms”) are now widely used research tools in ecology. However, the small size, short duration and often simplified biological and physical complexity of mesocosm experiments raises questions about extrapolating results from these miniaturized ecosystems to nature. Dimensional analysis, a technique widely used in engineering to create scale models, employs “compensatory distortion” as a means of maintaining functional similarity in properties and relationships of interest. An earlier paper outlined a general approach to applying dimensional analysis to the construction and interpretation of mesocosm experiments (Petersen and Hastings in Am Nat 157:324, 2001). In this paper we use examples, largely drawn from the aquatic literature, to illustrate how dimensional approaches might be used to maintain key ecological properties. Such key properties include effective habitat size, environmental variability, vertical and horizontal gradients, and interactions among habitats. We distinguish both continuous and discrete approaches that can be used to achieve functional similarity through compensatory distortion. In addition to its potential as a tool for improving the realism of experimental ecosystems, the dimensional approach points towards new options for developing, testing and advancing our understanding of scaling relationships in nature.

The Role of Students in the Co-creation of Transformational Knowledge and Sustainability Experiments: Experiences from Sweden, Japan and the USA

Accompanying realisations that engagement of multiple societal sectors (academia, industry, government, citizenry) and disciplines is required for formulating effective responses to complex sustainability challenges, calls for new forms of knowledge production are increasing in magnitude, both inside and outside the university. In parallel, experiences from the United Nations Decade of Education for Sustainable Development have highlighted that collaborations with societal stakeholders and experiential approaches are desirable for effective sustainability education. This article examines activities at three institutions—Lund University, Oberlin College and the University of Tokyo—to identify potential models for integrating students into the co-creation of transformational knowledge and sustainability experiments with faculty and multiple stakeholders. We examine the types of outputs that can ensue differing participation models, whilst also considering their impact on university and stakeholder efforts to advance societal sustainability. We argue that transformational sustainability partnerships integrating students can foster the alignment of the three university missions of education, research and community engagement with place-specific needs and sustainability challenges. Accordingly, efforts to promote experiential forms of sustainability education with societal stakeholders should refrain from focusing uniquely on education and encourage synergistic linking of all university missions. (Less)

Electricity and Water Conservation on College and University Campuses in Response to National Competitions among Dormitories: Quantifying Relationships between Behavior, Conservation Strategies and Psychological Metrics

“Campus Conservation Nationals” (CCN) is a recurring, nation-wide electricity and water-use reduction competition among dormitories on college campuses. We conducted a two year empirical study of the competition’s effects on resource consumption and the relationship between conservation, use of web technology and various psychological measures. Significant reductions in electricity and water use occurred during the two CCN competitions examined (n = 105,000 and 197,000 participating dorm residents respectively). In 2010, overall reductions during the competition were 4% for electricity and 6% for water. The top 10% of dorms achieved 28% and 36% reductions in electricity and water respectively. Participation was larger in 2012 and reductions were slightly smaller (i.e. 3% electricity). The fact that no seasonal pattern in electricity use was evident during non-competition periods suggests that results are attributable to the competition. Post competition resource use data collected in 2012 indicates that conservation behavior was sustained beyond the competition. Surveys were used to assess psychological and behavioral responses (n = 2,900 and 2,600 in 2010 and 2012 respectively). Electricity reductions were significantly correlated with: web visitation, specific conservation behaviors, awareness of the competition, motivation and sense of empowerment. However, participants were significantly more motivated than empowered. Perceived benefits of conservation were skewed towards global and future concerns while perceived barriers tended to be local. Results also suggest that competitions may be useful for “preaching beyond the choir”–engaging those who might lack prior intrinsic or political motivation. Although college life is distinct, certain conclusions related to competitions, self-efficacy, and motivation and social norms likely extend to other residential settings.

A method for measuring depth-integrated community metabolism in experimental planktonic-benthic ecosystems

We developed incubation chambers of clear acrylic extending the full depth of the water column to measure in situ depth-integrated community metabolism in experimental planktonic–benthic ecosystems. A magnetic stirring apparatus at mid-depth in each chamber prevented stratification and maintained a vertical turnover time that roughly matched turnover in the experimental ecosystems. We used the chambers in light–dark experiments to partition the depth-integrated photosynthesis and respiration occurring in the experimental ecosystems among water column, wall periphyton, and benthic communities. Community metabolism measured with the chambers was positively related to the chlorophyll-a concentrations of the water column and wall periphyton communities. We also found close agreement between the summation of partitioned community metabolism measured in the chambers and an independent measure of total ecosystem metabolism in the experimental ecosystems. Incubations in chambers and in light–dark bottles revealed similar patterns of water column and wall periphyton community metabolism, but magnitudes differed. In addition to application in experimental ecosystems, this incubation chamber technique may provide an efficient and realistic measure of water column and benthic metabolism and nutrient uptake in lakes and estuaries.

Teaching systems thinking to 4th and 5th graders using Environmental Dashboard display technology

Tackling complex environmental challenges requires the capacity to understand how relationships and interactions between parts result in dynamic behavior of whole systems. There has been convincing research that these “systems thinking” skills can be learned. However, there is little research on methods for teaching these skills to children or assessing their impact. The Environmental Dashboard is a technology that uses “sociotechnical” feedback–information feedback designed to affect thought and behavior. Environmental Dashboard (ED) combines real-time information on community resource use with images and words that reflect pro-environmental actions of community members. Prior research indicates that ED supports the development of systems thinking in adults. To assess its impact on children, the technology was installed in a primary school and children were passively exposed to ED displays. This resulted in no measurable impact on systems thinking skills. The next stage of this research examined the impact of actively integrating ED into lessons on electricity in 4th and 5th grade. This active integration enhanced both content-related systems thinking skills and content retention.

Relationships between Spatial Metrics and Plant Diversity in Constructed Freshwater Wetlands.

The diversity of plant species and their distribution in space are both thought to have important effects on the function of wetland ecosystems. However, knowledge of the relationships between plant species and spatial diversity remains incomplete. In this study, we investigated relationships between spatial pattern and plant species diversity over a five year period following the initial restoration of experimental wetland ecosystems. In 2003, six identical and hydrologically-isolated 0.18 ha wetland “cells” were constructed in former farmland in northeast Ohio. The systems were subjected to planting treatments that resulted in different levels of vascular plant species diversity among cells. Plant species diversity was assessed through annual inventories. Plant spatial pattern was assessed by digitizing low-altitude aerial photographs taken at the same time as the inventories. Diversity metrics derived from the inventories were significantly related to certain spatial metrics derived from the photographs, including cover type diversity and contagion. We found that wetlands with high cover type diversity harbor higher plant species diversity than wetlands with fewer types of patches. We also found significant relationships between plant species diversity and spatial patterning of patch types, but the direction of the effect differed depending on the diversity metric used. Links between diversity and spatial pattern observed in this study suggest that high-resolution aerial imagery may provide wetland scientists with a useful tool for assessing plant diversity.