Jenny M. Dauer

Contribution of Calcium Oxalate to Soil-Exchangeable Calcium

Abstract Acid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypothesized that the highly insoluble biomineral Ca oxalate might represent an additional soil Ca pool that is not detected in standard measures of soil-exchangeable Ca. We asked whether several standard method extractants for soil-exchangeable Ca could also access Ca held in Ca oxalate crystals using spike recovery tests in both pure solutions and soil extractions. In solutions of the extractants ammonium chloride, ammonium acetate, and barium chloride, we observed 2% to 104% dissolution of Ca oxalate crystals, with dissolution increasing with both solution molarity and ionic potential of cation extractant. In spike recovery tests using a low-Ca soil, we estimate that 1 M ammonium acetate extraction dissolved sufficient Ca oxalate to contribute an additional 52% to standard measurements of soil-exchangeable Ca. However, in a high-Ca soil, the amount of Ca oxalate spike that would dissolve in 1 M ammonium acetate extraction was difficult to detect against the large pool of exchangeable Ca. We conclude that Ca oxalate can contribute substantially to standard estimates of soil-exchangeable Ca in acid forest soils with low soil-exchangeable Ca. Consequently, measures of exchangeable Ca are unlikely to fully resolve discrepancies in ecosystem Ca mass balance unless the contribution of Ca oxalate to exchangeable Ca is also assessed.

Conservation of Energy: An Analytical Tool for Student Accounts of Carbon-Transforming Processes

Energy and energy conservation are powerful concepts for understanding biological systems, but helping students use these concepts as tools for analysis of these complex systems poses special challenges. This chapter focuses on three issues that arise in teaching about energy in biological systems: 1. Understanding the purpose of the concept of energy. Students often use energy in cause-effect stories related to vitality or animation (“energy is what makes things happen”), rather than treating energy as an enduring entity that can be used as a tool for analysis. In instruction, we treat the principles of energy conservation as “rules to be followed.” Students use these rules to trace energy through processes and observe how energy constrains these processes. 2. Identifying forms of energy in living systems. Students often associate energy with cause, vitality, or growth in ways that do not align with scientific conceptions of energy. In our instruction, we make simplifications we feel are important for helping students develop a working discourse about energy in science classrooms: we describe energy in different forms, one of which is chemical energy that is associated with bonds of molecules. 3. Tracing energy separately from matter. Students often lack a sense of necessity for distinguishing between matter and energy (“glucose is energy”). We use physical representations of energy (twist ties) and a framework for scaffolding distinct accounts of matter and energy to help students focus on explaining matter and energy as separate entities.

Connections between Student Explanations and Arguments from Evidence about Plant Growth

In an analysis of 22 middle and high school student interviews, we found that many students reinterpret the hypotheses and results of standard investigations of plant growth to match their own understandings. Students may benefit from instructional strategies that scaffold their explanations and inquiry about how plants grow.

Application of construal level and value-belief norm theories to undergraduate decision-making on a wildlife socio-scientific issue

ABSTRACT One aim of science education is to develop scientific literacy for decision-making in daily life. Socio-scientific issues (SSI) and structured decision-making frameworks can help students reach these objectives. This research uses value belief norm (VBN) theory and construal level theory (CLT) to explore students’ use of personal values in their decision-making processes and the relationship between abstract and concrete problematization and their decision-making. Using mixed methods, we conclude that the level of abstraction with which students problematise a prairie dog agricultural production and ecosystem preservation issue has a significant relationship to the values students used in the decision-making process. However, neither abstraction of the problem statement nor students’ surveyed value orientations were significantly related to students’ final decisions. These results may help inform teachers’ understanding of students and their use of a structured-decision making tool in a classroom, and aid researchers in understanding if these tools help students remain objective in their analyses of complex SSIs.

In Their Own Words: The Significance of Participant Perceptions in Assessing Entomology Citizen Science Learning Outcomes Using a Mixed Methods Approach

A mixed methods study was used to transcend the traditional pre-, post-test approach of citizen science evaluative research by integrating adults’ test scores with their perceptions. We assessed how contributory entomology citizen science affects participants’ science self-efficacy, self-efficacy for environmental action, nature relatedness and attitude towards insects. Pre- and post-test score analyses from citizen scientists (n = 28) and a control group (n = 72) were coupled with interviews (n = 11) about science experiences and entomological interactions during participation. Considering quantitative data alone, no statistically significant changes were evident in adults following participation in citizen science when compared to the control group. Citizen scientists’ pre-test scores were significantly higher than the control group for self-efficacy for environmental action, nature relatedness and attitude towards insects. Interview data reveal a notable discrepancy between measured and perceived changes. In general, citizen scientists had an existing, long-term affinity for the natural world and perceived increases in their science self-efficacy, self-efficacy for environmental action, nature relatedness and attitude towards insects. Perceived influences may act independently of test scores. Scale instruments may not show impacts with variances in individual’s prior knowledge and experiences. The value of mixed methods on citizen science program evaluation is discussed.

A framework for pollination systems thinking and conservation

Abstract We conducted interviews with 16 postsecondary students at a large public university on pollination systems knowledge. A semi-structured interview protocol was developed with open-ended prompts to elicit student explanations of pollination systems. Congruent themes were developed through coding of the interview transcripts into low, medium, and high sophistication of responses. From this, we developed a framework of pollination knowledge informed by systems thinking models that describe structures of plants and pollinators, conservation behaviors, and the function of pollination systems. The framework described can be used to explain students’ understanding of pollination systems and identify strengths and gaps in this knowledge. We propose this framework may also be used as the basis for instrument development evaluating the impacts of educational programming designed to improve students’ pollination knowledge.