In addition to the projects outlined below, I recently served as an expert on the Minneapolis Parks and Recreation Board Climate Resiliency Working Group. This was a year long process to help plan for the next 20 years of the parks in Minneapolis. You can read more about their proposed plan here: MPRB Draft 2021 Comprehensive Plan
Adaptation to future rainfall patterns under climate change
Climate change is affecting both the volume and distribution of rainfall. This is expected to affect the growth and reproduction of plant populations. Local adaptation, the pattern whereby natural selection in response to local environmental conditions leads to differences among populations, might affect how populations are affected by and will respond to changing rainfall.
In 2016, I conducted an experiment to investigate how common ragweed, Ambrosia artemisiifolia, may respond to future rainfall changes by simulating both decreased and increased rainfall (see a brief blog post about the experiment on the News page). I used event-based rainout shelters to reduce rainfall on some plots, and I added water via watering cans to other plots to increase rainfall. I included seeds from 26 populations sampled across the range to examine how this response depends on the historical climate of each seed source. For this experiment, I used space awarded to me through the University of Minnesota Living Labs Program. The research plot was located on East Bank on the University of Minnesota campus.
I found results to suggest that ragweed may spread and become more abundant in areas projected to become hotter and drier during the summer. I also found that population responses to altered rainfall dependent on historical climate, suggesting that local adaptation has the potential to shape future response of ragweed populations to climate change. The results of this research were published in Oecologia.
The spatial scale of adaptation
There are many examples of adaptation to different environments at a single spatial scale, be it adaptation to climate across large distances or adaptation to serpentine soils at a scale of tens of meters. However, there are relatively few studies that have combined sampling across multiple spatial scales in a single species to simultaneously determine how patterns of adaptation might change across space in response to both environmental and geographic distances.
The spatial scale of adaptation was the primary focus of my dissertation, where I examined adaptation among populations separated by relatively small geographic distances (~1-2 km) and up to much larger distances (~1600 km). I used a combination of manipulative experiments (common gardens, reciprocal transplants) and population genetics in common ragweed to investigate these interests. I recently published the population genetics component in PLoS Genetics.
Amanda J. Gorton 