Mapping a forest mosaic – A comparison of vegetation and bird distributions using geographic boundary analysis

Many areas of ecological inquiry require the ability to detect and characterize change in ecological variables across both space and time. The purpose of this study was to investigate ways in which geographic boundary analysis techniques could be used to characterize the pattern of change over space in plant distributions in a forested wetland mosaic. With vegetation maps created using spatially constrained clustering and difference boundary delineation, we examined similarities between the identified boundaries in plant distributions and the occurrence of six species of songbirds. We found that vegetation boundaries were significantly cohesive, suggesting one or more crisp vegetation transition zones exist in the study site. Smaller, less cohesive boundary areas also provided important information about patterns of treefall gaps and dense patches of understory within the study area. Boundaries for songbird abundance were not cohesive, and bird and vegetation difference boundaries did not show significant overlap. However, bird boundaries did overlap significantly with vegetation cluster boundaries. Vegetation clusters delineated using constrained clustering techniques have the potential to be very useful for stratifying bird abundance data collected in different sections of the study site, which could be used to improve the efficiency of monitoring efforts for rare bird species.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43882/1/11258_2004_Article_358203.pd

Iterative Design of a Simulation-Based Module for Teaching Evolution by Natural Selection

Background: This research builds on a previous study that looked at the effectiveness of a simulation-based module for teaching students about the process of evolution by natural selection. While the previous study showed that the module was successful in teaching how natural selection works, the research uncovered some weaknesses in the design. In this paper, we used design-based research to investigate how design changes to the module affected not only students’ understanding of the concepts but also their usage of misconceptions in the assessments. We present results from two studies. In study 1, we looked at gains in understanding on a pre and post-assessment for students who used the revised version of the module. We also examined misconception uses in their answer selections. In study 2, we compared the performance on a summative assessment between students who used the revised version and students who used the original version of the module. We also looked at misconception uses in their answer selections. Results: In study 1, we saw a significant improvement in the pre-post assessment for students who used the revised version. In study 2, we did not find a significant difference on the overall performance outcome between students who used the revised and those that used the original version of the module. In both studies, however, we saw a lower use of misconceptions after students used the revised module. In particular, we saw less use of the adaptive mutation misconception, the belief that mutations are adaptive responses to the environment and are biased towards advantageous mutations. This is promising because in the previous study there was no evidence of decreased use of this misconception. Conclusions: Students showed learning gains on all targeted key concepts, and reduced expression of all targeted misconceptions, which was not found previously for students using the older workbook version of the module. In particular, the revised version appears to help students overcome the adaptive mutation misconception. This article demonstrates how design-based research can contribute to the ongoing improvement of evidence-based instruction in undergraduate biology classrooms

A new assessment of graph construction competency for undergraduate biology students

With an increasing emphasis on teaching the skills and processes of science in the undergraduate biology classroom, working with and interpreting data has become an important part of the curriculum. Visual representations are a key tool when examining data, especially graphs. Undergraduate biology students notoriously have trouble both making good graphs and interpreting graphs. Yet, although there is an extensive literature on graph interpretation challenges amongst students, there has been much less work on the confusions students exhibit when constructing graphs. On the path to creating tools to help teach graphing to biology students, we have been building a new performance-based assessment of graph construction competence. The assessment presents students a research question and asks them to make graphs to test a hypothesis drawn from that question. The graphs are auto-scored for a number of practices associated with making good graphs. The digital nature and auto-scoring has allowed us to provide this assessment and analyze results at larger scales than previous assessments, gathering data that will help focus teaching tools on the areas of highest need. In this workshop, each participant will take one version of the graphing assessment themselves (about 20–30 minutes) and then we will discuss the experience. After talking about how well the assessment lines up to the graphing practices you look for in your students, the presenter will show data on where we find biology students struggle, drawn from students in a diverse set of classes and institutions. Bring your laptop (Mac or Windows only).Note: the creative commons license below is for the abstract and talk only, not the software

Interplanetary mesoscale observatory (InterMeso): A mission to untangle dynamic mesoscale structures throughout the heliosphere

Mesoscale dynamics are a fundamental process in space physics, but fall within an observational gap of current and planned missions. Particularly in the solar wind, measurements at the mesoscales (100s RE to a few degrees heliographic longitude at 1 au) are crucial for understanding the connection between the corona and an observer anywhere within the heliosphere. Mesoscale dynamics may also be key to revealing the currently unresolved physics regulating particle acceleration and transport, magnetic field topology, and the causes of variability in the composition and acceleration of solar wind plasma. Studies using single-point observations do not allow for investigations into mesoscale solar wind dynamics and plasma variability, nor do they allow for the exploration of the sub-structuring of large-scale solar wind structures like coronal mass ejections (CMEs), co-rotating/stream interaction regions (CIR/SIRs), and the heliospheric plasma sheet. To address this fundamental gap in our knowledge of the heliosphere at these scales, the Interplanetary Mesoscale Observatory (InterMeso) concept employs a multi-point approach using four identical spacecraft in Earth-trailing orbits near 1 au. Varying drift speeds of the InterMeso spacecraft enable the mission to span a range of mesoscale separations in the solar wind, achieving significant and innovative science return. Simultaneous, longitudinally-separated measurements of structures co-rotating over the spacecraft also allow for disambiguation of spatiotemporal variability, tracking of the evolution of solar wind structures, and determination of how the transport of energetic particles is impacted by these variabilities

Double-crested cormorant predation of yellow perch in Les Cheneaux Islands, Lake Huron

Master of ScienceNatural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/114254/1/39015043205411.pd

How Effective Are Simulated Molecular-level Experiments for Teaching Diffusion and Osmosis?

Diffusion and osmosis are central concepts in biology, both at the cellular and organ levels. They are presented several times throughout most introductory biology textbooks (e.g., Freeman, 2002), yet both processes are often difficult for students to understand (Odom, 1995; Zuckerman, 1994; Sanger et al., 2001; and results herein). Students have deep-rooted misconceptions about how diffusion and osmosis work, especially at the molecular level. We hypothesized that this might be in part due to the inability to see and explore these processes at the molecular level. In order to investigate this, we developed new software, OsmoBeaker, which allows students to perform inquiry-based experiments at the molecular level. Here we show that these simulated laboratories do indeed teach diffusion and osmosis and help overcome some, but not all, student misconceptions

Impact of Double-Crested Cormorant Predation on the Yellow Perch Population in the Les Cheneaux Islands of Michigan

The Michigan Department of Natural Resources, in conjunction with the University of Michigan and the U.S. Fish and Wildlife Service, initiated a research study to determine the impact of double-crested cormorants (Phalacrocorax auritus) on the yellow perch (Perca flavescens) population in the Les Cheneaux Islands area of northern Lake Huron. Aerial and nesting colony counts were conducted to monitor cormorant abundance. Creel census counts and tagging of 8,400 perch were used to study perch abundance. We collected 373 cormorants to study food habits via stomach-content analysis. We found that (1) cormorants fed heavily on yellow perch in early spring, but over the entire season only 10 percent of their diet was perch; (2) alewives (Alosa pseudoharengus) and sticklebacks (Culaea inconstans, Pungitius pungitius, Gasterosteus aculeatus) made up the major portion of the cormorants’ diet; (3) cormorants removed only 2.3 percent of the available perch biomass (v. 1.8 percent by anglers over the same period); (4) most fish taken by cormorants were less than 150 mm long; (5) total annual perch mortality was about 45 percent, of which less than 9 percent was due to cormorants; and (6) cormorants accounted for only 0.8 percent of the mortality of legal-size perch (≥178 mm), whereas summer sport fishing accounted for 2.5 percent. Thus, although the impact of cormorants on the perch population may vary slightly from year to year, we conclude that cormorant predation had minimal impact on the local perch population