Research

Our research addresses key questions in ecology, conservation, and evolutionary biology by integrating field-based, greenhouse, and growth chamber experiments with laboratory and analytical techniques.

You do not have to have a research project in mind before conducting research in my lab. We will collaborate on developing a project together! Collaborations with students have made my research expand in new, fun, and interesting directions.

Fitness consequences of plasticity

An organism's phenotype is the product of genetics and the environment. The environmental contribution, or plasticity, can arise from conditions experienced during an organism's development, but can also emerge in response to the conditions experienced by its parents. We study interactions between within-generation and transgenerational plasticity and their effects on phenotypic variation and fitness using a variety of environmental manipulations and study species. Topics of investigation include maternal vs. paternal environmental effects, the influence of mating system and the pollination environment, and the role of DNA methylation in generating transgenerational responses (in collaboration with Dr. Debbie Thurtle-Schmidt).

Consequences of climate change

In plants, life history transitions are often initiated by dependable combinations or sequences of cues that are indicative of favorable conditions. We are exploring the consequences of shifting conditions on growth and development in several ways:

Climate change is likely to alter some cues at different rates, while other cues, like photoperiod, will remain unaffected. We are examining how disassociations between temperature and photoperiod will constrain the expression of adaptive life history transitions.
Winter durations are becoming shorter with more frequent freeze/thaw events in the spring. We are studying how these dynamics affect vernalization, dormancy dynamics, and spring phenological synchrony.
Extreme weather events are becoming more frequent. We are interested in how plants respond to extreme heat events, cold snaps, and periods of drought.

Daylength and temperature upon first flower

Constraints to adaptive evolution

Phenology mediates assisted gene flow success.

Natural selection will favor adaptive evolution, or an increase in the frequency of phenotypes that are well suited for a given environment. However, other processes and phenomena can impact a population's ability to adapt to local conditions. For instance, gene flow from populations experiencing contrasting conditions can restrict adaptive evolution by introducing maladapted alleles to a focal population. Conversely, gene flow can spread advantageous alleles across populations or increase genetic variation, thereby facilitating responses to selection. We are exploring adaptive evolution in populations experiencing dissimilar patterns of selection when gene flow varies in strength and direction within and across generations.

Conservation and community engagement

Natural populations negatively impacted by climate change, urbanization, and other stressors may need human intervention to persist. One strategy for increasing population growth and adaptive evolution in declining populations is to move individuals from one portion of a species' range to another (assisted gene flow) or to move individuals beyond a species' current range boundary in anticipation of future favorable migratory events (assisted migration). We study the contexts in which these managements plans are feasible and likely to succeed.

In addition, we have started a long-term monitoring project in collaboration with Mecklenburg County (NC) that explores the factors contributing to the decline of Helianthus schweinitzii (Schweinitz's Sunflower).

We have also begun digitizing the Davidson College Arboretum in ArcGIS, which will provide a resource for tracking tree phenology, carbon content, and other variables of interest.

Project ENABLE

Susana is a founding member of Project ENABLE, which is an online resource for Enriching Navajo as a Biology Language for Education. We present new and existing biology terminology in Diné Bizaad as a way to preserve this language while also enabling better scientific communication. Ongoing efforts include the creation of education materials to help people understand these biological concepts and to learn the terminology in Diné Bizaad.

Project website: enablenavajo.org/navajo/

More information: spectrumnews1.com/wi/milwaukee/news/2021/10/11/breaking-language-barriers--project-enable-creates-new-navajo-words-for-scientific-terms