Abiotic Conditions, Local Adaptation, and Growth of Pacific Madrone (Arbutus menziesii Pursh)
In collaboration with Dr. Laura DeWald, Dr. Richard Sniezko, Dr. Marianne Elliott, and Dr. Gary Chastagner, I investigated growth and mortality in Pacific madrone, a hardwood tree found on the western coast of the US and into Canada. We looked to see if there are correlations between the abiotic conditions in a madrone seed’s location of origin and how it grows in new locations. The broader aim of this work is to inform seed sourcing strategies for restorations across the western coast of the US and Canada. Often, seeds are chosen assuming there is a high degree of local adaptation, and so relatively local seed sources are used. With climate change; however, there is some move to see if some seed source translocations might be justifiable to help buffer populations against warmer, potentially drier conditions.
In line with local adaptation, we expected that trees from seed sources closer to a planting location would be likely to have lower mortality and probably higher growth. While this was generally true, we did find some seed sources that had relatively high growth and low mortality across planting sites. You can find the manuscript for this publication here!
Nonlocal species invasion in tallgrass prairies
As my undergraduate honors thesis, advised by Dr. Cathy Pfister (UChicago) and Adrienne Ernst (Northwestern), I looked at how the composition and amount of nonlocal species propagule pressure (e.g. seeds) impacted nonlocal species invasion success in an experimental prairie. This study is part of a larger set of studies and it specifically aims to see if heavily managing for some nearby nonlocal, invasive species would be more successful than managing for all of them (which is often logistically infeasible) while attempting to do a prairie restoration. If some nonlocal species will compete with one another and stifle each others growth then perhaps it is not as important to manage for them; if there are nonlocal species that seem to really facilitate further invasion then it could be a focus of management.
I found that, unsurprisingly, the more incoming nonlocal seeds there were, the more nonlocal species biomass would establish in the plots. However, there was not a clear correlation between the number of nonlocal species seeds entering the plot and the number of species who actually established. When the analysis were split by the degree of phylogenetic relatedness of the group of incoming nonlocal species, I found that at moderate levels of relatedness, there was a negative correlation between species richness and the volume of nonlocal species biomass that established. This indicates the potential for interspecies competition between incoming nonlocal species at moderate phylogenetic relatedness. See poster (to the left) or full thesis PDF for more details.
I presented this work at the Ecological Society of America 2018 meeting, receiving 1st place student poster in the Restoration Ecology section (tweet from ESA). This work built on a project at an REU at the Chicago Botanic Garden (with Adrienne Ernst), for which I also made a little youtube video talking about nonlocal species invasion and phylogenetic relatedness.
