Research

Strodestudents-768x576Science Education

Data Nuggets are classroom activities, co-designed by scientists and teachers, which give students practice interpreting quantitative information and making claims based on evidence. They are created from ongoing scientific research and provide a brief background on a scientist and their study system, a dataset from their research, and challenge students to answer a scientific question using the dataset to support their claim. The goal of Data Nuggets is to engage students in the practices of science through an innovative approach that combines scientific content from authentic research with key concepts in quantitative reasoning.

Data Nugget efficacy study

To assess the efficacy of Data Nuggets we are currently running an efficacy study in classrooms across the country. The evidence from this study will demonstrate whether short, targeted interventions of classroom activities embedded within a typical curriculum can impact student outcomes. We expect students in classrooms using Data Nuggets will demonstrate:

  1. Deeper understanding of quantitative reasoning in the context of science
  2. Improved understanding of the practices and processes of science, particularly in the areas of analyzing and interpreting data and using mathematics and computational thinking
  3. Greater engagement in the practices of science in the classroom
  4. Greater motivation to engage in science and improved general interest in science.

Invasion Biology

The number of invasive species is growing every year, as plants, animals, and microbes are introduced into habitats where they did not historically occur. Invasive species are of concern for scientists and land managers because of their detrimental effects on biodiversity and ecosystem functioning. To help mitigate their effects it is important to understand what processes cause a small fraction of introduced species to become troublesome invaders.

I am interested in learning if and when natural enemies influence invasive species performance, and how the fitness effects of natural enemies change over the course of invasion. To address my questions I use a combination of observational field studies, common gardens and meta-analyses of existing work. Located in old-field communities near the Kellogg Biological Station, my experiments look at the effects of biotic interactions on species of three statuses – native, exotic non-invasive, and invasive.

Screen Shot 2013-09-20 at 8.56.16 PMThe role of natural enemies on native, exotic, and invasive species performance

Natural enemies, such as herbivores and pathogens, are major drivers of both plant community structure and population dynamics. As a result, enemies play key roles in influencing plant distributions, including spread of exotic species that escape enemies during biological invasions. Elton (1958) was the first to recognize the dual role played by natural enemies during invasion: release from enemies from the native range may play a role in the explosive population growth rates of invasive species, and acquisition of enemies in the exotic range may explain why so many of the plants introduced around the world fail to establish and spread. My field research addresses these predictions, and I ask:

  1. Do invasive, exotic, and native species experience different amounts of damage from natural enemies?
  2. Does enemy release result in increased performance for invasive species compared to native and non-invasive exotic species?
  3. Do the benefits of enemy release diminish over time as invasives integrate into natural communities? 

Are altered biotic interactions during invasion a general mechanism to explain invasive success?

While many studies have shown differences in enemy damage between native, exotic, and invasive species it is not yet known if these differences translate into fitness effects. Though a plant may experience less damage in its exotic range, or compared to native species in its exotic range, this does not necessarily translate into increased performance and the potential to invade if damage has minimal effects on plant fitness. To fully examine the role of biotic interactions during invasion, we must determine if and how often enemies affect the fitness of introduced and native species. To address this question I am currently performing a meta-analysis of the invasion literature, looking at studies that have manipulated biotic interactions on native, exotic, and invasive species.

garlic mustardAllelopathic effects of Alliaria petiolata on rhizobia and its implications for native legume performance

Invasive species Alliaria petiolata (garlic mustard), has been shown to harm a common soil mutualists for native plants, mycorrhizal fungi. Its allelopathy reduces the performance of this key mutualist, thus indirectly decreasing the performance of their plant mutualist partners. It is possible that these allelopathic effects may extend to other soil biota. Along with Tomomi Suwa and two undergraduate collaborators (Cristy and Tina), we are testing if A. petiolata’s allelochemicals have similar negative effects on another important symbiotic organism: rhizobia, a nitrogen fixing bacteria that forms symbiotic relationships with legumes.

SaveSave

SaveSave

SaveSave

SaveSave

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s