LCC News

Temperature and rainfall controls on coastal wetlands in the northern Gulf of Mexico

Gulf Coastal Plains & Ozarks LCC News -

Coastal wetlands along the northern Gulf of Mexico are diverse. Salt marshes, mangrove forests, and salt flats are all different kinds of tidal saline wetland ecosystems that can be found in the region. In addition to supporting fish and wildlife, these coastal wetlands protect coastal communities, provide seafood, improve water quality, store carbon, and provide recreational opportunities.

Coastal ecologists have long known that temperature and rainfall regimes control the distribution and dominance of these different ecosystems. However, constraints in data quality and access have limited efforts to characterize the influence of climate on the region’s coastal wetlands. Below, I’ve included a link to a recent study published in Nature Climate Change where we used data from 10 estuaries in five states (TX, LA, MS, AL, and FL) to quantify these linkages and evaluate the implications of alternative future climate scenarios.

The results identify thresholds for mangrove forests, salt marshes, and salt flats. Within the region, small changes in temperature and/or rainfall can lead to large changes in ecosystem structure and function. For example, small changes in winter air temperature regimes (i.e., freeze events) can lead to mangrove expansion at the expense of salt marsh. And, in drier areas (south Texas), small changes in rainfall can alter salinity regimes and lead to the expansion or contraction of salt flats. Ecologists refer to these changes as ecological regime shifts. In coastal wetlands, such regime shifts can result in the gain and/or loss of certain ecosystem goods and services.

Citation: Gabler, C. A., M. J. Osland, J. B. Grace, C. L. Stagg, R. H. Day, S. B. Hartley, N. M. Enwright, A. S. From, M. L. McCoy, and J. L. McLeod. 2017. Macroclimatic change expected to transform coastal wetland ecosystems this century. Nature Climate Change.

Link: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3203.html

Up next: Read about a GCPO LCC-sponsored coastal resilience initiative along the Gulf Coast

Temperature and rainfall controls on coastal wetlands in the northern Gulf of Mexico

Gulf Coastal Plains & Ozarks LCC News -

Coastal wetlands along the northern Gulf of Mexico are diverse. Salt marshes, mangrove forests, and salt flats are all different kinds of tidal saline wetland ecosystems that can be found in the region. In addition to supporting fish and wildlife, these coastal wetlands protect coastal communities, provide seafood, improve water quality, store carbon, and provide recreational opportunities.

Coastal ecologists have long known that temperature and rainfall regimes control the distribution and dominance of these different ecosystems. However, constraints in data quality and access have limited efforts to characterize the influence of climate on the region’s coastal wetlands. Below, I’ve included a link to a recent study published in Nature Climate Change where we used data from 10 estuaries in five states (TX, LA, MS, AL, and FL) to quantify these linkages and evaluate the implications of alternative future climate scenarios.

The results identify thresholds for mangrove forests, salt marshes, and salt flats. Within the region, small changes in temperature and/or rainfall can lead to large changes in ecosystem structure and function. For example, small changes in winter air temperature regimes (i.e., freeze events) can lead to mangrove expansion at the expense of salt marsh. And, in drier areas (south Texas), small changes in rainfall can alter salinity regimes and lead to the expansion or contraction of salt flats. Ecologists refer to these changes as ecological regime shifts. In coastal wetlands, such regime shifts can result in the gain and/or loss of certain ecosystem goods and services.

Citation: Gabler, C. A., M. J. Osland, J. B. Grace, C. L. Stagg, R. H. Day, S. B. Hartley, N. M. Enwright, A. S. From, M. L. McCoy, and J. L. McLeod. 2017. Macroclimatic change expected to transform coastal wetland ecosystems this century. Nature Climate Change.

Link: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3203.html

Temperature and rainfall controls on coastal wetlands in the northern Gulf of Mexico

Gulf Coastal Plains & Ozarks LCC News -

Coastal wetlands along the northern Gulf of Mexico are diverse. Salt marshes, mangrove forests, and salt flats are all different kinds of tidal saline wetland ecosystems that can be found in the region. In addition to supporting fish and wildlife, these coastal wetlands protect coastal communities, provide seafood, improve water quality, store carbon, and provide recreational opportunities. Coastal ecologists have long known that temperature and rainfall regimes control the distribution and dominance of these different ecosystems. However, constraints in data quality and access have limited efforts to characterize the influence of climate on the region’s coastal wetlands. Below, I’ve included a link to a recent study published in Nature Climate Change where we used data from 10 estuaries in five states (TX, LA, MS, AL, and FL) to quantify these linkages and evaluate the implications of alternative future climate scenarios. The results identify thresholds for mangrove forests, salt marshes, and salt flats. Within the region, small changes in temperature and/or rainfall can lead to large changes in ecosystem structure and function. For example, small changes in winter air temperature regimes (i.e., freeze events) can lead to mangrove expansion at the expense of salt marsh. And, in drier areas (south Texas), small changes in rainfall can alter salinity regimes and lead to the expansion or contraction of salt flats. Ecologists refer to these changes as ecological regime shifts. In coastal wetlands, such regime shifts can result in the gain and/or loss of certain ecosystem goods and services.

Citation: Gabler, C. A., M. J. Osland, J. B. Grace, C. L. Stagg, R. H. Day, S. B. Hartley, N. M. Enwright, A. S. From, M. L. McCoy, and J. L. McLeod. 2017. Macroclimatic change expected to transform coastal wetland ecosystems this century. Nature Climate Change.

Link: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3203.html

Final EPA/USGS Technical Report: Protecting Aquatic Life from Effects of Hydrologic Alteration

Appalachian LCC News -

This report presents a literature review of natural flow and a description of the potential effects of flow alteration on aquatic life, as well as examples of water quality criteria that some states have developed to support natural flow and maintain healthy aquatic life. The report also describes a flexible technical and scientific framework that state water managers can consider if they are interested in developing narrative or numeric targets for flow that are protective of aquatic life.

This scientific and technical report is non-regulatory and does not affect or constrain state or tribal discretion.

Hydrologic alteration can include an increase or decrease in water volume, seasonal flow disruption, and dramatic variation in water temperature. Hydrologic alteration can affect aquatic species’ ability to spawn, gather nutrients from the stream system, access high-quality habitat, and more. Hydrologic alteration may be further exacerbated through climate change. Recent climate trends have included the change in frequency and duration of extreme weather events, such as droughts and floods, which can have an impact on flow and affect aquatic life. Maintaining flow targets may help increase a stream’s resilience to climate change by reducing or avoiding intensification of existing stressors.

Previously, the report underwent a public comment period, the draft version of this document can be found in the docket EPA-HQ-OW-2015-0335.

Scientists: Strong evidence that human-caused climate change intensified 2015 heat waves

Appalachian LCC News -

The fifth edition of Explaining Extreme Events from a Climate Perspective presents 25 peer-reviewed research papers that examine episodes of extreme weather of 2015 over five continents and two oceans. It features the research of 116 scientists from 18 countries analyzing both historical observations and changing trends along with model results to determine whether and how climate change may have influenced the event.

The strongest evidence for a human influence was found for temperature-related events --- the increased intensity of numerous heat waves, diminished snowpack in the Cascades, record-low Arctic sea ice extent in March and the extraordinary extent and duration of Alaska wildfires.

“After five years of the BAMS Explaining Extreme Events report, we’re seeing mounting evidence that climate change is making heat waves more extreme in many regions around the world,” said lead editor Stephanie C. Herring, a scientist with NOAA’s National Centers for Environmental Information.  "As we get better at distinguishing the influence of climate change from natural variability, the local significance and impacts of this global phenomenon are becoming clearer."

Evidence of climate change in 2015 flooding, fires – and sunshine

Numerous other events of 2015 were made more extreme by climate change, the report found.  The probability of “sunny day” tidal flooding events in the Miami area, like the one that inundated coastal areas that September, has risen 500 percent since 1994, according to one study.  Human-induced climate change likely contributed to the record high intensity of west North Pacific typhoons and the record amount of winter sunshine in the United Kingdom.

But researchers found no evidence of an overall climate change signal in the delayed onset of the Nigerian spring rainy season or in the extreme daily rainfall totals that inundated Chennai, India in December.  There was likewise no evidence that the extreme cold winter conditions over the northeast United States in 2015 were made more likely by human-induced climate change.

Lessons learned over the past five years

More than 100 papers examining extreme events have been accepted for publication in this special report since its inaugural issue in 2012.  These studies take a place-based and event-specific approach to identifying the role of climate change, and answer the question of how much a particular recent event’s likelihood of recurrence or intensity has changed relative to the past.

While there’s mounting evidence in the role of climate change in amplifying the severity of heat waves, evidence of a climate change signal has not been found in a majority of extreme precipitation studies published in this special edition, Herring said.

However, she cautioned that the lack of clear evidence of a climate signal did not necessarily mean climate change played no role in an event. A “null” result could mean the event fell within the bounds of natural variability. It could also mean that the framing of the research question or the method of analysis chosen requires further refinement and development.

Identifying analytical methods that work better than others

Contributing authors choose the event they wish to study, so the new studies are neither a random sample nor a comprehensive survey of extreme weather events.  They do illustrate how various methods can be applied to extreme event analysis, she said, and in cases where multiple groups look at the same event, the relative skill of different approaches can be compared.

“With this report, we continue to document scientists’ growing ability to identify how climate change influences today’s weather,” said Jeff Rosenfeld, editor-in-chief of the Bulletin of the American Meteorological Society, which independently conducts the peer reviews for studies included in this special report. “These accessible and brief papers show the scientific community and the public that once seemingly impossible insights about climate impacts are now within the capability of timely, rigorous science.”

Five NOAA scientists served as editors of Explaining Extreme Events of 2015 from a Climate Perspective: Herring, James Kossin, and Carl Schreck III of NOAA’s National Centers for Environmental Information along with Martin P. Hoerling and Andrew Hoell with NOAA’s Earth Systems Research Laboratory. Peter A. Stott with the UK Met Office Hadley Centre also served as an editor.

View the full report online

The U.S. Global Change Research Program Wants to Hear From You

Appalachian LCC News -

This special report provides an update to the physical climate science presented in the Third National Climate Assessment released in 2014. The draft CSSR provides updated climate science findings and projections, and is an important input to the authors of the next quadrennial NCA (NCA4), expected in 2018.

All comments must be input within the USGCRP Review and Comment System, via an online mechanism or an off-line spreadsheet for later upload. If you are interested in registering as an expert reviewer, please click here and log in using existing credentials or by establishing an account.

The deadline for comment is 3 February 2017. More information can be found on our Open Notices page.

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