[ES_JOBS_NET] USGS Mendenhall Postdoc Research Opportunity: Diked wetlands

[Gonneea, Meagan]

Interested applicants are strongly encouraged to contact the Research
Advisors early in the application process to discuss project ideas: Kevin D
Kroeger, PhD <https://www.usgs.gov/staff-profiles/kevin-d-kroeger> and Meagan
Eagle Gonneea, PhD
<https://www.usgs.gov/staff-profiles/meagan-eagle-gonneea>18-23. Predicting
responses to sea level rise and restoration in diked salt marshes
<https://www.usgs.gov/centers/mendenhall/18-23-predicting-responses-sea-level-rise-and-restoration-diked-salt-marshes>

*Closing Date: January 6, 2020*

This Research Opportunity will be filled depending on the availability of
funds. All application materials must be submitted through USAJobs by 11:59
pm, US Eastern Standard Time, on the closing date.

How to Apply <https://www.usgs.gov/centers/mendenhall/when-and-how-apply>

Tidal wetlands are key coastal ecosystems that provide a wealth of services
to society, including recreation, bird and fish habitat, protection from
coastal storms, and rapid storage of atmospheric carbon in soil. Under
natural conditions, tidal exchange between wetlands and the coastal ocean
sustains these important ecosystem services since dynamic biogeochemical
responses result in wetlands that are responsive to rising seas through
elevation gain (Gonneea et al. 2019) and transgression. A substantial
portion of coastal wetlands, however, have managed hydrology, and their
management conditions and histories have important consequences for the
carbon cycle processes that build elevation through soil formation, and
thus for resilience to accelerating sea-level rise. Tidal restrictions and
other managed coastal hydrology, including dikes, tide gates, road and
railroad berms or culverts, water control structures, and ditches, alter
both sea and aquifer elevations and disrupt the dynamic elevation response
of fresh and saline coastal wetlands. In the U.S., we and our colleagues
have estimated that there are ~0.48 million hectares of
restricted/impounded wetlands, and ~0.24 million hectares of drained former
wetlands (Kroeger et al. 2017; Crooks et al. 2018; Fargione et al. 2018).

Related research indicates that alterations of wetland hydrology result in
changes in water level, period and frequency of soil inundation, water
salinity and chemistry, vegetation cover and productivity, habitat quality,
soil carbon storage and elevation trajectory. When coastal wetlands are
impounded, biogeochemical conditions favor the production of methane, a
potent greenhouse gas, while the rate of elevation gain is diminished
(Kroeger, et al. 2017, Gonneea et al. in prep.). Where wetlands are
drained, enhanced aerobic respiration drives massive loss of soil carbon,
as emitted carbon dioxide (IPCC 2013), driving rapid loss of soil
elevation. As a result, under a range of widespread conditions, managed
coastal landscapes have both impaired resilience to sea-level rise and
diminished habitat value, while they emit substantial anthropogenic
greenhouse gas. Finally, the same barriers that impound or drain the
wetlands also serve as barriers to migration, preventing transgression.

Primary hypotheses are that restoration of saline, tidal flows in these
managed wetlands will reduce greenhouse gas emissions, while restoring
natural soil accretion, hazard protection, carbon storage, and ecosystem
conditions. However, data and knowledge on responses to management and to
environmental change remain limited, hampering our ability to predict the
future condition of managed wetlands. Yet, federal agencies, including the
Fish & Wildlife Service and National Park Service, as well as state and
local governments, and other entities that manage impounded or drained
wetlands, are increasingly facing decisions and requesting guidance related
to elevation and habitat change under accelerating relative sea-level rise,
as well as information on greenhouse management potential in coastal
ecosystems. Research at the USGS Woods Hole Science Center has focused on
broadly characterizing the consequences of a range of management actions in
coastal wetlands, and on developing data and tools to guide and inform
decisions based on consideration of habitat, elevation resilience, change
in coastal hazards, and greenhouse gas management potential.

We seek a postdoctoral fellow to conduct basic and applied research that
addresses the consequences of management actions in coastal wetlands, in
the context of accelerating sea level rise. Following are examples of
relevant questions that the project might address, though other topics may
be within the scope of interest:

   -

   How do managed wetlands respond to sea-level rise?
   -

   How does the interaction of sea-level rise with groundwater drive
   changes in vegetation, elevation, biogeochemistry, and resilience?
   -

   How does altered tidal hydrology associated with diking and impoundment
   or drainage alter biogeochemical processes that drive soil accretion and
   greenhouse gas emissions?
   -

   What are the key drivers of soil carbon and gas flux rates, and can
   responses of those drivers to hydrological management predict feedbacks on
   climate?
   -

   How do interactions of sea level rise and hydrological management
   predict wetland persistence, change in coastal hazards, or habitat change?
   -

   What are the trajectories of change in response to restoration, and can
   they be predicted?
   -

   What are the key drivers that must be considered in new predictive
   models for a range of sea-level and management change scenarios?



-- 

Meagan Eagle Gonneea, PhD
Research Scientist
USGS Woods Hole Coastal and Marine Science Center
384 Woods Hole Road
Woods Hole, MA 02543
(508) 457-2280
m: (774) 810-0538
Office: Gosnold 25
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