Research projects
Research themes
Advocating for soils to be included in the understanding of ecosystem processes through education and outreach
Influence of soil on post-disturbance resilience (fire, forestry, agriculture)
Exploring how soils will be altered as the climate changes
Spatial variability in soil properties
Soil-water relations across the landscape
Soil as a driver for habitat suitability and flora/fauna distribution patterns
Research projects
Photo ©Brittany Johnson
How can we better deliver wetland carbon data for policy- and decision-makers?
Wetlands disproportionately contribute to carbon storage, storing 30% (202–754 PgC) of the global soil organic carbon (SOC) stock (1500 PgC) while only occupying 8–11% of the land surface. Inland freshwater wetlands (teal carbon) accounts for 10 times more SOC than blue carbon sites in the US, but we have limited knowledge about these landscape features, their fluxes, or their impacts on emission. The goal of this project is to develop state-of-the-art foundational baseline data on SOC stocks for all inland wetlands in the US that can be integrated into local, state, and national level policies, conservation and restoration prioritization activities, and wetland condition assessments.
Linking practice to policy change in urban community gardens
This project seeks to understand what would make gardeners feel safe in their UCGs and identify interventions on local and regulatory levels that centers community feedback, which could mitigate exposure to contaminants in UCGs. In general, there is an absence of guidelines for UCGs, which makes it very difficult to make recommendations about what is safe. Moreover, guidelines that do exist have not considered community feedback. Legacies of environmental racism have resulted in limited choices for underserved gardeners who seek access to healthy food, and are already vulnerable to multiple environmental injustices. This project will address these issues in UCGs in order to improve their health.
Photo ©Brittany Johnson
Photo ©Brittany Johnson
Blue carbon, green fields: Incorporating marine carbon into terrestrial farms
What happens when sea lettuce clogs up the works at a beautiful Pacific Northwest shellfish farm? Vacuum it up and use it to fertilize farms! This project investigates the creation of a climate smart commodity in seaweed. This project aims to help local farms, marine and terrestrial, benefit from the growth of this sea lettuce and feed our local communities. Who doesn't want fresh oysters on the half shell paired with fresh sourdough bread and a crispy salad??? Uh oh, now I'm hungry...
Building capacity for tribal, community, and agency research in urban watersheds
Seattle's Duwamish River was declared an EPA Superfund site in 2001. For decades, the Duwamish Tribe, the Duwamish River Cleanup Coalition (DRCC), and their partners have driven accountability and contaminant remediation, while supporting the connections of local residents to this industrialized yet vibrant river. While some cleanup has occurred, remaining contaminants and stormwater runoff continue to impact community resilience and coastal ecosystem health. This project links urban research through co-created community-driven assessment, data-collection, visioning, and dissemination.
Photo ©Jovelle Tamayo
Photo ©Wendy Gibble
Using soil property analysis to support the recovery of endangered plant species
Why do plants grow where they grow? What keeps them from expanding? This project aims to explore the habitat requirements of endangered endemic plants, Umtanum desert buckwheat (Eriogonum codium) and White Bluffs Bladderpod (Physaria douglasii), and how we can support the establishment of new colonies and recovery of existing groups. characterize the soil environment of multiple sites (including the natural site), test the effects of grass-specific herbicides on plants in a nursery setting, evaluate seedling survival at the natural site, and attempt to establish plants at the natural site to develop out-planting protocols.
Hydrophobicity as a result of burn severity in the Pacific Northwest
The effects of climate change are evident as fire regimes shift towards larger and more frequent burns. Planning the future of land management and the maintenance of ecosystem health requires understanding the linkages between above- and below-ground processes. Soil experiences many chemical and physical changes during fire, including changes in how the soil interacts with water. Depending on the temperature of the fire and the properties of the soil/vegetation, hydrophobic layers (water repellent, HPLs) can be created and naturally occurring HPLs enhanced or destroyed. These HPLs can reduce or prevent water infiltration thereby affecting water availability for pioneer or recovering species. They can also increase the risk of topsoil loss via erosion. HPLs can persist for varying lengths of time from seconds to years after a fire; thus the impacts of HP can be seen long after the fire event. We would like to better understand how HPLs vary with time, space, and fire severity in the PNW in order to predict recovery and resilience of ecosystems to fire.
Photo ©Jalene Weatherholt
Photo ©Brittany Johnson
Relationships between soil chemistry, microclimate, and Pinus ponderosa growth
As forest water stress is expected to increase due to changes in climate, the high tolerance of ponderosa pine (Pinus ponderosa, PIPO) to drought and fire is predicted to allow this species to expand its range by over 20%. While effective silvicultural management will require understanding past responses of PIPO to climate, most existing dendroclimatology research ignores the role of soils in regulating plant growth. We are examining the possible origins of noise in tree rings, isotopes, and dendrometer-based increment growth based on differences in soil microclimate, nutrient status, and soil water availability. Initially, we are focusing on Washington State, with plans to later expand this study across the range of PIPO in the western United States.
How do soils help to shape patterns in biogeochemistry, flow, and temperature in streams?
Soils and streams have an irrefutable bond. Nutrients from the soil leach in to waterways, water is exchanged, pollutants captured and treated, habitats formed for macro- and micro-organisms, and thermal refugia created and destroyed for aquatic species. Understanding how these processes are connected will help to answer some critical questions regarding drivers of water quality and potential effects of climate change. We currently lack a mechanistic understanding of how relative mixtures of surface water and groundwater change both at the site scale as well as longitudinally along a stream through time. Observational studies suggest significant spatial heterogeneity from a stream’s source (spring) to the mouth of the watershed in physical properties such as temperature and chemical properties such as nutrients, ions, and carbon speciation and concentrations. Many of these processes are driven by the characteristics of the surrounding soil environment.
Photo ©USGS
Photo ©Virginia McDaniel, USFS
Responses of soil chemical, physical, and biological characteristics to prescribed fire
Fire is one of the most transformative natural ecosystem process. As humans have embraced the incorporation of fire back into landscapes where historic fire intervals were short, the use of prescribed fires have been the preferred method of reintroduction. The effects of fire on the soil (and therefore the rest of the ecosystem) are often dramatic, but vary significantly depending on the fire itself. This study investigates the response of the soil system to these events from the perspective of changes in chemical properties, physical structure and soil-water relations, and the response of the soil biological community. Utilizing new techniques like environmental DNA and collaborating with a large and diverse group of researchers, we hope to examine how soil processes help to shape ecosystem recovery and resilience to fire.
How can we restore old growth forests and still produce timber?
There is a fundamental problem in plantation-style planting: the amount of timber produced and the quality of that timber decline over time. The question of how to create appropriate adaptive management strategies to balance the health of the ecosystem with the economic, cultural, and recreational value of the land came to the forefront of forestry research and long term productivity sites (LTEPs) were established. The goal of these is to create old-growth forests (~10 trees/acre) while harvesting hardwood or conifer understory rotations. Resampling LTEPs is key to asses their effectiveness, and current campaigns are underway.
Figure: LTEP
Photo ©Brittany Johnson
Examining the lasting effects of land management on forest soil health
Forest management techniques effect the ecosystem on a myriad of time scales. This project explores the influence of different harvest strategies ten years after implementation at a long-term ecological productivity study site in northern Oregon. Understanding how silvicultural practices change the environment will shine a light on balancing the sustainable use of forestry products with ecosystem productivity.