​​​​​​​​​​​​​​​Current Research

The unifying theme of this body of work is to understand the fundamental dynamics of ecosystems and the influence of natural and anthropogenic perturbations/feedbacks on ecosystem functions.

                       

                       Ecosystem dynamics along  terrestrial-aquatic interfaces 

                                        The primary objective of this project is to examine how coupled plant-soil-water-microbe

                                        interactions, and related biogeochemical transformations and fluxes, respond to variable water

                                        availability and exposure to salt along coastal terrestrial aquatic interfaces. We are currently

                                        studying the underlying mechanisms driving carbon transformations and the magnitude of

                                        these exchanges to and from the atmosphere, soils, porewater, trees, and surface waters across

                                        the headwater-to-estuary continuum of Pacific Northwest, USA coastal watersheds. A

                                        combination of in situ measurements, high-resolution monitoring, and lab incubations are

                                        being used for development of a reactive transport model adapted for tidal systems. These

                                        models help to evaluate parameterization of the Energy Exascale Earth Systems Model

                                        (E3SM).Funding provided by Pacific Northwest National Laboratory, Lab Directed

                                        Research and Development. Lead PI: Nick Ward


                       Mechanistic understanding of tree methane emissions

                                         Among the largest uncertainties in the global CH4 budget is the role of forest trees. While     

                                         upland forest soils are typically a sink of atmospheric CH4, the emission of CH4 from tree

                                         stems to the atmosphere may balance, or even exceed this sink. This project uses molecular

                                         level tools to understand the microbial mechanisms driving methanogenesis and methane

                                         oxidation inside trees. A crowd-sourcing approach is being used to gather tree core samples

                                         from researchers around the world studying tree methane fluxes to develop understanding

                                         across numerous types of environments and climatic conditions. Funding is provided

                                         by Pacific Northwest National Laboratory, Lab Directed Research and Development.
                                        
Lead PI: Nick Ward


                       Metabolic response of eelgrass to environmental stress

                                        Seagrass is a critical habitat for a variety of ecosystem services such as fisheries, pollutant  
                                        detoxification, and sequestration of “blue” carbon. Significant effort has been made to restore  
                                        eelgrass, a keystone species in Puget Sound, but the success rate of restoration is limited by a
                                        lack of fundamental knowledge of how eelgrass responds/adapts to changing ocean      
                                        conditions. We are developing a suite of biomarker proxies for eelgrass health based on  
                                        cellular metabolite abundance. Funding provided by Pacific Northwest National Laboratory  
                                        Energy and Environment Lab Directed Research and Development (PNNL-EED-LDRD).
                                        Lead PI: Nick Ward


                       The role of priming effects on the conversion of blue

                       carbon to CO2 in the coastal zone 

                                         Blue carbon storage in coastal marshes is thought to be an essential mechanism for

                                         atmospheric CO2 sequestration, however, the release and subsequent breakdown of stored  

                                         blue carbon due to sea level rise is a potentially significant positive feedback for climate  

                                         change. This study utilizes a combination of innovative incubation approaches and cutting

                                         edge organic geochemical (e.g. FT-ICR-MS, LTQ Orbitrap MS, NMR, and GC-MS) and

                                         molecular biological analyses (e.g. metatranscriptomics) to answer fundamental questions

                                         concerning the mechanisms driving global biogeochemical cycles. Funding provided by the  

                                        Department of Energy Joint Genome Institute. Lead PI: Thomas Bianchi

                               Net eco
system exchange of the lower Amazon River

                                         This project seeks to unravel the sequence of processes and sources of

                                         terrestrially-derived organic matter that culminate in the immense CO2 outgassing to

                                         the atmosphere from tropical rivers worldwide. Funding provided by the Fundação de

                                         Amparo à Pesquisa do Estado de São Paulo (FAPESP) and the National Science

                                         Foundation (NSF). Lead PI: Jeff Richey 

                                         Website: http://boto.ocean.washington.edu/story/show/10

                                         

 ​                       Biotic and hydrologic controls on CaCO3 dissolution  and 

                       GHG emissions in the Big Cypress National Preserve      

                               This project tests the hypothesis that organic matter dynamics control the rate and geometry

                                          of limestone dissolution in low-relief karst landscapes. In particular we are studying the Big

                                          Cypress National Preserve near the Florida Everglades, where unique biogeochemical and

                                          hydrologic conditions maintain "Cypress domes," i.e. circular patterns of Cypress trees with

                                          depressions formed from carbonate dissolution. These conditions also result in groundwater  

                                          anoxia and very high levels of methane. Funding provided by NSF. Lead PI: Matt Cohen, UF  


​                        Linking carbon exchange between coastal wetland and

                       shelf environments in the Gulf of Mexico 

​                                       The focus of this project is to optimize algorithms that integrate optical and chemical data of

                                          dissolved organic matter (DOM) based on proxies of predicted flux from marshes to coastal

                                          waters through estuaries. Coastal wetlands (including marshes) are important sources of

                                          DOM and CDOM, both of which originate as ‘blue carbon’ – carbon derived from primary

                                          production in vegetated coastal wetlands.  The position of these wetlands in the global

                                          landscape represents a key interface between terrestrial and marine ecosystems.               

                                          Funding provided by NASA. Lead PI: Chris Osburn, NCSU                   

 

                  





Ecosystems Research

Nick Ward, PhD