Supporting Teacher Learning about Disciplinary Literacy: An Exploration of Professional Development, Social Studies Teachers' Thinking, and Inherent Challenges

This dissertation is comprised of three manuscripts that explore aspects of teacher professional development (PD) for disciplinary literacy. These aspects include (1) the ways that five core features of PD – duration, coherence, collective participation, active learning, and content focus – appear in a PD program focused on developing teacher thinking about disciplinary literacy; (2) the conceptions that social studies teachers held about disciplinary literacy while they participated in a PD program focused on disciplinary literacy; and (3) the challenges inherent to disciplinary literacy that impede the enactment of PD focused on disciplinary literacy. Data for this dissertation was collected through a yearlong qualitative study of a county-based PD program that focused on developing teacher thinking about disciplinary literacy. Data collected include observations of PD sessions, interviews with the PD Coordinator, interviews with and observations of four participating social studies teachers, and artifact collection. The analysis of the PD program (Chapter 2), based on an application of Desimone’s (2009) five-feature conceptual framework for studying PD, finds that most of the core features of PD were only partially realized, including the content focus and coherence. The exploration of four social studies teachers’ thinking (Chapter 3) reveals a continuum of disparate conceptions about disciplinary literacy and how it can be taught. A review of the challenges that arose during the enactment of the PD program (Chapter 4) uncovers some challenges inherent to learning about disciplinary literacy, including the disciplinary expertise gap between teachers and disciplinary experts. Taken as a whole, these sets of findings suggest that disciplinary literacy is a particularly problematic topic for teachers to learn because part of the necessary content focus is the work of disciplinary experts. Since disciplinary expert work takes place outside the settings of schools and traditional PD sites and may not be familiar to teachers, PD programs focused on disciplinary literacy confront the added challenges of bridging the world of the disciplinary expert with the world of the teacher. This, in turn, places higher demands on teacher knowledge development than might be encountered in PD programs that deal exclusively with school-based topics. To assist in meeting these demands, this dissertation proposes a set of design principles for planning and facilitating PD focused on disciplinary literacy (Chapter 5). Based on a translation of the five-feature conceptual framework and the findings of this dissertation, these design principles suggest actionable means for implementing core features of PD focused on disciplinary literacy.PHDEducational StudiesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/138641/1/jaumen_1.pd

Burmese pythons in Florida: A synthesis of biology, impacts, and management tools

Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive Burmese pythons. We describe existing control tools and review challenges to productive research, identifying key knowledge gaps that would improve future research and decision making for python control. (119 pp

Enhanced hyporheic exchange flow around woody debris does not increase nitrate reduction in a sandy streambed

Anthropogenic nitrogen pollution is a critical problem in freshwaters. Although riverbeds are known to attenuate nitrate, it is not known if large woody debris (LWD) can increase this ecosystem service through enhanced hyporheic exchange and streambed residence time. Over a year, we monitored the surface water and pore water chemistry at 200 points along a ~50m reach of a lowland sandy stream with three natural LWD structures. We directly injected 15N-nitrate at 108 locations within the top 1.5m of the streambed to quantify in situ denitrification, anammox and dissimilatory nitrate reduction to ammonia, which, on average, contributed 85%, 10% and 5% of total nitrate reduction, respectively. Total nitrate reducing activity ranged from 0-16µM h-1 and was highest in the top 30cm of the stream bed. Depth, ambient nitrate and water residence time explained 44% of the observed variation in nitrate reduction; fastest rates were associated with slow flow and shallow depths. In autumn, when the river was in spate, nitrate reduction (in situ and laboratory measures) was enhanced around the LWD compared with non-woody areas, but this was not seen in the spring and summer. Overall, there was no significant effect of LWD on nitrate reduction rates in surrounding streambed sediments, but higher pore water nitrate concentrations and shorter residence times, close to LWD, indicated enhanced delivery of surface water into the streambed under high flow. When hyporheic exchange is too strong, overall nitrate reduction is inhibited due to short flow-paths and associated high oxygen concentrations

Influence of woody debris on nutrient retention in catastrophically disturbed streams

The role of woody debris in nutrient cycling was investigated in two catastrophically disturbed streams in the Pacific Northwest that had been subjected to large inputs of wood. One study site in each catchment had all woody debris removed (take section), while the debris in the other study site was left intact (leave section). Nitrate, phosphate and chloride (a conservative tracer) were released in each section and nutrient retention was monitored at downstream stations. Phosphate was removed from solution more than nitrate, probably due to the high N : P ratio in the stream water. However, there were no major differences in nutrient retention between the take and leave sections. In contrast, experiments in recirculating chambers showed that woody debris and cobbles exhibited higher nitrate and phosphate uptake per unit surface area than sand/gravel or fine particulate organic matter. The high uptake rates of woody debris and cobbles may be related to their suitability for colonization by heterotrophic microorganisms and algae. Wood may not influence nutrient retention significantly at the reach level because of its low surface area relative to other substrates. However, wood may be very important at small spatial scales because of its high uptake activity