PALMQUIST LAB
Plant Ecology at Marshall University
Our research focuses on quantifying vegetation and ecosystem dynamics over space and time and identifying how ecohydrology, climate, fire, and soil properties shape those patterns. In addition, a key goal of our research is to understand how plant communities will response to ongoing and future global environmental change. An important motivation for our work is to inform landscape conservation and land mangement decision-making. We collect field data, use existing large observational data sets and remote sensing, and implement simulation modeling to answer these questions in a variety of ecosystems, including temperate forests and woodlands, drylands dominated by big sagebrush, and salt marshes.
Fire Effects on Forest Plant Communities
In the temperate deciduous forest region of eastern North America, the exclusion and suppression of fire in fire-adapted forests has had important consequences for forest structure and species composition, most notably a decrease in oak regeneration and herbaceous diversity and an increase in shade-tolerant, fire-sensitive tree species. Ongoing research in the lab is focused on quantifying the effects of fire frequency (including fire suppression) on forest plant communities over multiple decades.
Projects:
Long-term effects of fire frequency on oak regeneration, plant biodiversity, and pollinator habitat in the Wayne National Forest, Ohio. Collaborators: Dr. Todd Hutchinson (USFS) and Dr. Pamela Puppo (Marshall U). Students: Rebekah Shupe, Moses Shafer, Reyna Abreu-Vigil, Khyla Johnson, and Jacob Webb.
Status of mixed pine-oak forests in West Virginia in relation to fire history. Collaborators: Dr. Tom Saladyga (Concord U). Students: Cassie Bacon.
CURRENT RESEARCH
Community Assembly in Longleaf Pine Plant Communities
Multiple ecological processes, which often operate at different spatial and temporal scales, are thought to act synergistically to influence the number and identity of species in local communities. Thus, a key challenge in ecology is to identify those processes and determine their relative importance. In this body of research, we explore vegetation patterns in the longleaf pine ecosystem and quantify the relative importance of multiple ecological processes (fire, soil properties, climate, biogeography history, competition, stochasticity) structuring those patterns over both space and time.
PAST RESEARCH
Drought Impacts along Soil Moisture Gradients
The effects of drought on plant communities include loss of biodiversity, declines in plant biomass, and shifts in species composition. However, those impacts are likely to vary substantially depending on existing soil moisture and plant adaptations to drought. We are quantifying the effects of drought in longleaf pine (Pinus palustris) plant communities of the southeastern U.S by re-sampling permanent plots that have experienced increases in drought in the last several decades. We are documenting how drought impacts vary along existing soil moisture gradients and identifying whether drought-intolerant species are more sensitive and are preferentially lost.
Projects:
Quantifying the vulnerability of longleaf pine woodlands to drought. Collaborators: Lisa Giencke (The Jones Center). Students: Aria Searles, Moses Shafer, Mary Doherty, and Cassie Bacon.
Dryland Plant Comunity Response to Multiple Global Change Drivers
Globally, dryland plant communities are projected to be especially affected by climate change because their structure and function are closely tied to precipitation and temperature. However, the impacts of changing climate will not be uniform and will depend on spatially-structured environmental conditions. Our research uses an individual-based plant simulation models to explore the impacts of climate change, wildfire, and cheatgrass invasion on big sagebrush plant communities across their spatial extent to guide landscape conservation and prioritization.
Projects:
Quantifying the interacting effects of climate change, wildfire, and cheatgrass invasion on big sagebrush plant community composition and habitat quality.
Leveraging livestock grazing as a tool to reduce cheatgrass biomass, fine fuels, and wildfire risk.
Collaborators: Dr. John Bradford (USGS), Dr. William Lauenroth (Yale U), Dr. Daniel Schlaepfer (USGS), Dr. Martin Holdrege (USGS), and Dr. Kevin Doherty (USFS). Students: Maggie England, Rachel Renne, and Alexis Belt.
Effects of Sea-level Rise and Storm Intensification on Coastal Vegetation