We enjoy collaborating! Please feel free to contact us.
Climate adaptation and ecology and evolution of species range limits
We study plants, often monkeyflowers (Mimulus species), to understand (1) niche evolution and the underpinnings of distributions, (2) adaptations, tolerances, and evolutionary potentials to adapt to varying environments and (3) consequences of historical and experimental gene flow on these processes. We examine the role of selection, gene flow, and range limits in determining plant adaptations. For example, we study Mimulus laciniatus across its species range. Populations across a broad elevation gradient are being examined in common gardens representing the climate breadth of the species range, and beyond. Population genetics/genomics are being used to understand adaptive responses in the context of gene flow. Continuing research includes climate-based and local-scale niche evolution and niche convergence among closely related species and their genomic basis. [Current collaborators include Ben Blackman, Katie Ferris, Nic Kooyers, Daniel Runcie, Sharon Strauss, and Kevin Rice. Support includes a grant from the Hellman Faculty Fund to JS and an NSF grant (IOS-1558035) to BB, NK, JS, and DR.]
Adaptation in novel environments
We are investigating mountain plants in the California Sierra Nevada and Australian Alps and focusing on species range size and the role of gene flow on the processes of adaptation and tolerance to rapidly changing environments, including the recent exceptional California drought. Gene flow is manipulated experimentally and also assessed through genomics methods. The performance of mountain plants are being tested under a variety of conditions representing different types of environmental stress. Comparative studies include a variety of plant groups, including native grasses, sedges, and forbs. [Current collaborators include Erin Dickman (Yosemite N.P.), Ary Hoffmann, Megan Hirst, Pip Griffin, Neville Walsh, Molly Clemens, and Rachel Slatyer. Support includes a grant from the Hellman Faculty Fund to JS and an NSF grant (BIO/IRFP-1003009) to JS.]
Plant responses across environmental gradients in Yosemite
In addition to the above work in adaptation, we are studying the responses of mountain plants to local and regional scales of environmental variation in Yosemite National Park. In one study we are testing for the effects of stand-level environmental gradients on seedling recruitment and success of giant sequoia (Sequoiadendron giganteum). Our goal is to develop a sequoia seedling niche model based on seedling temperature, light, and soil characteristics in order to better understand seedling recruitment requirements to aid restoration efforts. In another study we are measuring the growth responses of seven species of meadow plants across meadows spanning a wide range of elevations in Yosemite National Park during both drought and non-drought years. Our aim is to understand how climate and local-scale variation in water availability translate to variation in plant performance. [Current collaborators include Molly Stephens, Laurel Sebastian, Michael Spaeth, Kaitlin Lubetkin, Alison Colwell, and Garrett Dickman. Support includes a grant from the Yosemite Conservancy to MS and JS and support from the NSF Yosemite REU at UC Merced.]
Conservation genomics of vernal pool ecosystems
Vernal pool ecosystems contain extremely high biodiversity, yet they are among the most endangered systems in California (~95% gone). We are conducting several studies to better understand the diversity of these critically endangered systems. We are using conservation genomics, focusing on a tribe of grasses specialized within California vernal pools (Orcuttieae), to better understand range-wide levels of genetic variation, and the potential sources and sinks of genetic variation in these fragmented remnant ecosystems. Additionally, we are testing DNA barcoding techniques as a means of detection for both plant soil seed banks and environmental DNA (eDNA) of plants and animals in vernal pools in general. [Current collaborators include Molly Stephens, Dannise Ruiz-Ramos, Michael Dawson, and Daniel Toews. Support includes a grant from the US Fish and Wildlife Service and Bureau of Reclamation to MS and JS and support from the UC Conservation Genomics Consortium to the Sexton and Dawson labs at UC Merced.]
The role of the microbiome in plant adaptation
All plants (and animals) are hosts to myriad internal microbes, yet we still know very little about the roles of this “microbiome” on plant adaptation and success. We are studying how the microbiome responds to environmental conditions and ultimately how these symbiotic microbes may alter or enhance plant performance in stressful conditions. Currently we are examining the microbiome of monkeyflowers under drought and range-limiting conditions and in vernal pool plants using next-generation DNA sequencing techniques. [Current collaborators include Carolin Frank, Mark Sistrom, Clarissa Nobile, Jackie Shay, and Lauren Brooks. Support includes a grant from the DOE Joint Genome Institute to MS, CF, and JS, and UC Merced Senate grants to JS, CF, and CN.]
Global change and sustainability science
We are fascinated, and motivated, by the question of how to manage ecosystems sustainably in the face of global change, and enjoy collaborating across traditional research fields.