This large project is led by the Pacific Northwest National Laboratory in collaboration with multiple partners, including the Smithsonian Environmental Research Center (SERC) and Argonne National Lab. The COMPASS - FME project aims to understand the coupled interactions of plants, microbes, soils/sediments, and hydrology within coastal systems to inform multi- scale, integrated models from reaction scales to the coastal terrestrial-aquatic interface (TAI). The project’s research emphasis is primarily on terrestrial and wetland processes that are influenced by coastal waters, such as the fluxes and transformations of carbon, nutrients, and redox elements through these systems. This project includes several national labs, and research institutions in the W. Basin of Lake Erie and Chesapeake Bay
The project comprises two parts: a field study and a coastal modeling study. COMPASS-FME: Field, Measurements, and Experiments, which focuses on field studies and associated process and ecosystem modeling of two coastal interfaces. COMPASS-GLM: Great Lakes Modeling focuses on modeling and analysis of coastal systems in the Great Lakes Region.
Dr. Weintraub is a co-Investigator on COMPASS-FME. COMPASS-FME seeks to advance a scalable, predictive understanding of the fundamental biogeochemical processes, ecological structure, and ecosystem dynamics that distinguish coastal terrestrial-aquatic interfaces (TAIs) from the purely terrestrial or aquatic systems to which they are coupled. To achieve the COMPASS vision, FME will focus on overarching long-term science questions: What fundamental mechanisms control the structure, function, and evolution of coastal TAIs? How do these fundamental mechanisms interact across spatial scales, and what interactions are most important to improving predictive models? The two-year COMPASS-FME pilot study aims to develop predictive understanding of the causes, mechanisms, and consequences of the shift between aerobic and anaerobic conditions at both saltwater and freshwater TAIs.
The Pilot Watershed Project: Does implementing best management practices reduce the potential for phosphorus runoff from agricultural fields?
Phosphorus (P) is an essential nutrient for plants and is often added
as fertilizer to farm fields. However, adding P to fields can be
problematic because P added to
agricultural fields can runoff into surface waters and contribute to
harmful algal blooms, including the bloom that shut down the Toledo
municipal water supply in August 2014.
The application of P fertilizers is often inefficient, as much of the P
forms complexes with soil particles and is unavailable to plants. In
addition, some of the P from previous fertilizer applications remains
bound to soil particles from year to year, becoming “legacy P”. After
several years of fertilization, a soil may become saturated with P, at
which point the ability of soil particles to bind additional P becomes
negligible. At this point, P inputs to surface waters may
increase—either by erosion of soil particles into waterways, or by
runoff of dissolved P that does not bind to P-saturated soils.
The Pilot Watershed Project will
advance state and national efforts to address
coastal eutrophication and hypoxia by simultaneously supporting agricultural production
and improving water quality. Located in the
Shallow Run watershed of Hardin County in
northwest Ohio, it integrates concentrated
implementation of agricultural best management practices with field-to-stream monitoring in a
limited geographic area to improve water quality
outcomes. To achieve higher implementation
rates by farmers, the five-year program tests
the strategy of agglomeration whereby growers
encourage neighbors to implement practices so
that the whole community receives greater cost
share benefits. The goal of our research, which began in Fall 2023 and is ongoing, is
to determine if implementing best management practices such as the use of cover crops and subsurface P fertilizer placement reduces the potential for P runoff from agricultural fields.
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Biological and geochemical controls on phosphorus bioavailability in arctic tundra
The
National Science Foundation funded this three-PI/three institution
collaborative project in August 2019. Research and sample collection
began in Summer 2021.
Phosphorus (P) is a nutrient essential for life but its supply in the
environment is often limited, resulting in P limitation to plant growth
and/or decomposition in some environments. Plants and microorganisms
take up P as dissolved phosphate in soil water. Phosphate is also
removed from solution by binding with soil minerals. In particular,
iron minerals strongly bind phosphate and may regulate its availability
to plants and microorganisms. This project will investigate how
geochemical and biological systems “compete” for phosphate in arctic
tundra soils near Toolik Field Station, Alaska, where soil warming and
permafrost thaw are altering carbon and water budgets, which in turn
affects soil moisture and nutrient availability. This research is
broadly important to understanding how soil properties (e.g., soil
saturation and pH) affect this competition for phosphate and
consequently influence plant growth and the ability of arctic
ecosystems to serve as future carbon sources or sinks. The implications
of this work extend beyond arctic systems and will increase the
fundamental understanding of soil P availability.
Winter snow depth as a driver of microbial activity, nutrient cycling, tree growth and treeline advance in the Arctic
The National Science Foundation funded this three-PI/two-institution collaborative project in 2015. The field experiment was setup in September 2016, and research will continue through August 2021. The position of the Arctic treeline is an important regulator of surface energy budgets, carbon cycling and subsistence resources in high latitude environments. It has long been thought that temperature exerts a direct control on the growth of treeline trees and the position of the treeline. However, our recent work in the Arctic with white spruce suggests that indirect effects of temperature on soil nutrient availability may be of equal or greater importance. These results highlight the importance of winter snow depth as a driver of tree growth. If our hypotheses are confirmed by our experimental manipulations, our findings will alter our predictions of where and when treelines may advance. Cold soils at the treeline, particularly during winter, may limit microbial activity and nutrient availability to the point where trees are barely able to survive and grow.
Measurements made during winter have revealed that Arctic forests
maintain snowpacks that are much deeper than observed at treeline.
Trees are thought to trap snow and lead to a deeper snowpack,
insulating the soil from cold air and allowing for greater overwinter
microbial activity and greater nutrient mineralization. Indeed, we
found a strong positive correlation between white spruce growth and
winter snow depth. We are now conducting a field experiment to isolate
the mechanisms underlying this correlation by using snowfences to
manipulate winter snow depth and fertilizer to increase soil nutrient
availability at three treelines that differ in soil moisture. To
provide a test of the importance of temperature as a direct control
on
treeline tree growth, we are experimentally warming tree shoots. We
predict that both experimental snow and nutrient additions
will lead to
large increases in microbial activity, photosynthesis, tree growth,
seed quality,
seed production, seedling establishment and recruitment
of new trees. We expect to observe
the greatest positive responses
where soils are wet and cold. Meanwhile, we predict that
shoot warming
will lead to negligible changes in growth. This research will elucidate
the relationship between snow depth and soil nutrient availability, and
determine the relative importance of nutrient and temperature
limitations at treeline to white spruce—a dominant member of the boreal
forest and the northernmost tree species in North America.
To view
past research projects, please click here. |
