RESEARCH
My graduate work was in two systems: Erythranthe laciniata, the cutleaf monkeyflower, an endemic forb in the Sierra Nevada; and three endgandered vernal pool grasses, Neostapfia colusana, Orcuttia inaequalis, and Tuctoria greenei. These systems are adapted to seasonal drought, but as climate change drives temperatures up and even further reduces rainfall, these plants will need to adapt or they will face extinction. My research focuses on the genetic variation present in populations across the range of all four species, and how this variation impacts the adaptive potential of those populations.
Chamaecrista fasciculata, the partridge pea, is the focus of my post-doctoral research. I am conducting a range-wide survey of the nitrogen-fixing bacteria that colonize the nodules the plant forms on its roots. I am also investigating the extent of local adaptation to local bacterial communities, as well as the impact of climate change on this symbiosis.
My monkeyflower work uses a resurrection framework to study the impacts of the 2012-2016 drought in California on populations across the species range. My study uses nine populations, with three each from low, middle, and high elevations.
My vernal pool grass work is a part of the California Conservation Genomics Project, and uses whole genome sequences from across the species ranges of all three grasses.
My partridge pea work is funded through an NSF-PRFB award.
MONKEYFLOWER LOCAL ADAPTATION
To study local adaptation and rangewide response to climate change, I implemented a common garden, reciprocal transplant, resurrection study. I planted three gardens at native monkeyflower populations at low, middle, and high elevations.
This study primarily addresses three questions:
Are low elevations less favorable than high elevations?
Are drought generation (2014) plants more fit in contemporary conditions than pre-drought generation (2006) plants?
Do drought generation plants show a signal of local adaptation?
MONKEYFLOWER DROUGHT STUDY
My lab experiment used plant growth chambers to test population-level, family-level, and generation-level responses to multiple conditions. I tested responses to non-drought and drought conditions in average and hot temperature environments, resulting in four treatments. Using family level replication, I can also test how quantitative genetic variation varies by population and generation in response to the treatments.
My lab experiment primarily addresses the following questions:
Do drought generation plants have higher fitness in drought conditions? And in hot conditions?
Do hot conditions adversely affect fitness?
Does intra-population variation shrink in adverse conditions?
Is QGV reduced in drought generation populations?
VERNAL POOL GRASSES POPULATION GENETICS
My vernal pool study uses DNA sequences collected from three endangered vernal pool grasses. Vernal pool habitat is highly fragmented and is susceptible to further development. Using whole genome resequencing, I can determine measures of classic population genetic variables like inbreeding, gene flow, and variation.
The primary questions of this study are:
Is variation distributed evenly across the range?
Are populations experiencing gene flow?
Are populations that are highly isolated experiencing inbreeding depression?
CHAMAECRISTA FASCICULATA RHIZOBIAL SYMBIOSIS
My partridge pea research uses a combination of field and genomic techniques to understand the symbiosis between the pea and its bacterial symbionts. I have three aims:
Aim 1: Characterize how rhizobial communities assemble across an environmental gradient with a range-wide landscape genomics study.
Aim 2: Evaluate the consequences of elevated temperatures for the plant-rhizobial symbiosis and determine if those consequences are related to range position.
Aim 3: Investigate local adaptation in the plant-rhizobial symbiosis in the context of climate change.
I am primarily hosted at UGA under the advisement of Dr. Jill Anderson, with additional advisement from Dr. Liana Burghardt at Penn State and Dr. Seema Sheth at NC State. All three are co-sponsors on my PRFB.