Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Increased salinity decreases annual gross primary productivity at a Northern California brackish tidal marsh

Journal Article · · Environmental Research Letters
 [1];  [2];  [3];  [3];  [3];  [4];  [5]
  1. University of British Columbia, Vancouver, BC (Canada); Univ. of British Columbia, Vancouver, BC (Canada)
  2. US Geological Survey, Menlo Park, CA (United States)
  3. US Geological Survey, Sacramento, CA (United States)
  4. California State University, East Bay, Hayward, CA (United States)
  5. University of British Columbia, Vancouver, BC (Canada)
+ Show Author Affiliations

Tidal marshes sequester 11.4–87.0 Tg C yr–1 globally, but climate change impacts can threaten the carbon capture potential of these ecosystems. Tidal marshes occur across a wide range of salinity, with brackish marshes (0.5–18 ppt (parts per thousand)) dominating global tidal marsh extents. A diverse mix of freshwater- and saltwater-tolerant plant and microbial communities has led researchers to predict that carbon cycling in brackish wetlands may be less sensitive to changes in salinity than fresh- or saltwater wetlands. Rush Ranch, a well-monitored brackish tidal wetland of the San Francisco Bay National Estuarine Research Reserve, experiences highly variable annual salinity regimes. Within a five-year period (2014–2018), Rush Ranch experienced particularly extreme drought-induced salinization during the 2014 and 2015 growing seasons. During drought years, tidal channel salinity rose from a 15 year baseline of 4.7 ppt to growing season peaks of 10.3 ppt and 12.5 ppt. Continuous eddy covariance data from 2014 to 2018 demonstrate that during drought summers, gross primary productivity (GPP) decreased by 24%, whereas ecosystem respiration remained similar among all five years. Stepwise linear regression revealed that salinity, not air temperature or tidal height, was the dominant driver of annual GPP. A random forest model trained to predict GPP based on environmental data from low salinity years (i.e. naive to salinization) significantly over predicted GPP in drought years. When growing season salinities were doubled, annual estimates of net ecosystem exchange of CO2 decreased by up to 30%. These results provide ecosystem-scale evidence that increased salinity influences CO2 fluxes dominantly through reductions in GPP. This relationship provides a starting point for incorporating the effect of changes in salinity in wetland carbon models, which could improve wetland carbon forecasting and management for climate resilience.

Research Organization:
California State University (CalState), Long Beach, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC); USGS
Grant/Contract Number:
SC0022185
OSTI ID:
2422075
Journal Information:
Environmental Research Letters, Journal Name: Environmental Research Letters Journal Issue: 3 Vol. 18; ISSN 1748-9326
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English

References (41)

Direct and Indirect Effects of Tides on Ecosystem-Scale CO 2 Exchange in a Brackish Tidal Marsh in Northern California journal March 2018
Constraining Marsh Carbon Budgets Using Long-Term C Burial and Contemporary Atmospheric CO 2 Fluxes journal March 2018
Effect of Drought-Induced Salinization on Wetland Methane Emissions, Gross Ecosystem Productivity, and Their Interactions journal August 2019
Effect of salinity-altering pulsing events on soil organic carbon loss along an intertidal wetland gradient: a laboratory experiment journal April 2013
Spatial and temporal variability in carbon dioxide and methane exchange at three coastal marshes along a salinity gradient in a northern Gulf of Mexico estuary journal February 2015
Salinization of coastal freshwater wetlands; effects of constant versus fluctuating salinity on sediment biogeochemistry journal September 2015
Impacts of increasing salinity and inundation on rates and pathways of organic carbon mineralization in tidal wetlands: a review journal November 2017
Halophyte ion regulation traits support saline adaptation of Lepidium latifolium, L. draba, and L. alyssoides journal February 2020
The Charisma of Coastal Ecosystems: Addressing the Imbalance journal February 2008
Carbon Sequestration and Sediment Accretion in San Francisco Bay Tidal Wetlands journal June 2012
Experimental Saltwater Intrusion Drives Rapid Soil Elevation and Carbon Loss in Freshwater and Brackish Everglades Marshes journal September 2019
Salinity Influence on Methane Emissions from Tidal Marshes journal July 2011
Salinity and Inundation Influence Productivity of the Halophytic Plant Sarcocornia pacifica journal October 2011
Tidal Freshwater Marsh Plant Responses to Low Level Salinity Increases journal November 2013
Relationships Between Salinity and Short-Term Soil Carbon Accumulation Rates from Marsh Types Across a Landscape in the Mississippi River Delta journal January 2017
Will inundation and salinity levels associated with projected sea level rise reduce the survival, growth, and reproductive capacity of Sarcocornia pacifica (pickleweed)? journal October 2012
Impacts of climate change on submerged and emergent wetland plants journal November 2016
Clonal variation in response to salinity and flooding stress in four marsh macrophytes of the northern gulf of Mexico, USA journal July 2006
Experimental influence of storm-surge salinity on soil greenhouse gas emissions from a tidal salt marsh journal October 2019
Carbon offset market methodologies applicable for coastal wetland restoration and conservation in the United States: A review journal January 2020
Controls on mangrove forest-atmosphere carbon dioxide exchanges in western Everglades National Park: MANGROVE CARBON DIOXIDE EXCHANGE journal June 2010
Hydrologic Export Is a Major Component of Coastal Wetland Carbon Budgets journal August 2020
The global distribution and trajectory of tidal flats journal December 2018
Methane emissions from wetlands: biogeochemical, microbial, and modeling perspectives from local to global scales journal February 2013
Agricultural peatland restoration: effects of land-use change on greenhouse gas (CO 2 and CH 4 ) fluxes in the Sacramento-San Joaquin Delta journal October 2014
A meta-analysis of soil salinization effects on nitrogen pools, cycles and fluxes in coastal ecosystems journal August 2016
On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm journal September 2005
Mechanisms of Salinity Tolerance journal June 2008
Estimating Global “Blue Carbon” Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems journal September 2012
Estuarine Vegetation at Rush Ranch Open Space Preserve, San Francisco Bay National Estuarine Research journal December 2011
Building Predictive Models in R Using the caret Package journal January 2008
Climate Change, Hurricanes and Tropical Storms, and Rising sea Level in Coastal Wetlands journal August 1997
Mechanisms mediating plant distributions across estuarine landscapes in a low-latitude tidal estuary journal January 2012
A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO 2 journal January 2011
A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands journal October 2015
Recent (1975–2004) Vegetation Change in the San Francisco Estuary, California, Tidal Marshes journal January 2012
Short-Term Response of Carbon Cycling to Salinity Pulses in a Freshwater Wetland journal January 2011
The thermodynamic ladder in geomicrobiology journal March 2011
CO2emission and soil Eh responses to different hydrological conditions in fresh, brackish, and saline marsh soils journal November 1991
Basic and extensible post-processing of eddy covariance flux data with REddyProc journal January 2018
Major role of marine vegetation on the oceanic carbon cycle journal January 2005

Similar Records

AmeriFlux FLUXNET-1F US-Srr Suisun marsh - Rush Ranch
Dataset · Sat Dec 31 23:00:00 EST 2022 · OSTI ID:2229389
AmeriFlux US-Srr Suisun marsh - Rush Ranch
Dataset · Mon Jan 29 23:00:00 EST 2018 · OSTI ID:1418685

Related Subjects

54 ENVIRONMENTAL SCIENCES
Brackish Wetland
Carbon Dioxide
Environmental Sciences & Ecology
Gross Primary Productivity
Meteorology & Atmospheric Sciences
Salinization