Nature always finds a way – coastal wetlands respond positively to global warming

Mangrove expansion and climatic warming may help ecosystems keep pace with sea level rise

From the BRITISH ECOLOGICAL SOCIETY

Sea level rise and extreme weather events have become harsh realities for those living along the world’s coasts. The record-breaking hurricanes of the past decade in the United States have led to staggering tolls on coastal infrastructure and communities, leading many local governments to consider the benefits of natural coastal barriers.

In a landmark study titled “Warming accelerates mangrove expansion and surface elevation gain in a subtropical wetland” a team of Villanova University biologists have documented that coastal wetlands in the southeastern United States are responding positively to rising temperatures both in their growth and in their ability to build soil to keep pace with sea level rise.

Published August 29 in the British Ecological Society’s Journal of Ecology, the study’s results are a ray of sunshine in the climate change forecast. Members of the research team included Glenn A. Coldren, J. Adam Langley, and Samantha Chapman, from Villanova University’s Department of Biology, Villanova, PA and Ilka C. Feller of The Animal-Plant Interaction Lab, Smithsonian Environmental Research Center, in Edgewater.

The Villanova research team’s two-year experiment, funded by grants from the National Aeronautics and Space Administration (NASA), was performed at the Kennedy Space Center (KSC) within the Merritt Island National Wildlife Refuge (MINWR) on Merritt Island. The KSC was an ideal location to conduct the research being situated at the intersection of two wetland biomes, salt marshes and mangroves. The implications for the KSC are serious since coastal wetlands and sand dunes help protect NASA’s $5.6 billion low-lying infrastructure against rising seas.

The large-scale warming experiment was conducted in place in the MINWR using large passive warming chambers to increase both marsh and mangrove ecosystem air temperatures. The Villanova researchers found that experimental warming both doubled plant height and accelerated the transition from marsh to mangrove.

Mangroves are woody trees with more complex roots than their grassy marsh plant counterparts. When subjected to temperatures similar to those that will occur in a warmer future, mangrove plots showed increased surface elevation which is a measure of the wetland’s ability to build soil and keep pace with sea level rise.

“Our study provides some evidence that the ongoing reshuffling of species on earth’s surface could allow for some adaptation to the same global changes that are causing them,” says Chapman. “Conserving and restoring our coastal wetlands can help humans adapt to climate change.”

With their unique structure and migration to higher latitudes caused by climate change, mangroves may help coasts keep pace with sea level rise and combat severe weather events like hurricanes. Expansion of these natural barriers in areas like the Kennedy Space Center may enhance the sustainability of coastal communities as they face accelerating sea-level rise in a warmer future.

“The study links the growth of individual plants, and particularly their roots, to the survival of an entire ecosystem. The long-term strength of the mangrove effects we identified may determine what the maps of our southeastern coastlines look like in the future,” says Langley. “This mangrove effect could benefit coastal wetlands around the world.”

“Our experiment highlights the impact multiple interacting aspects of climate change, such as warming and sea level rise, can have on the outcome of species invasions resulting from climate change — and on the capacity of those communities to protect shorelines,” concluded Coldren.

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The study: https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2745.13049?af=R

Abstract

Climatic warming can change how coastal wetland plants grow, thus altering their capacity to build land and keep pace with rising seas. As freeze events decline with climate change, mangroves expand their range to higher latitudes and displace salt marsh vegetation. Warmer air temperatures will likely alter above‐ and below‐ground plant dynamics as this dramatic coastal wetland biome shift proceeds, which in turn may result in changes in ecosystem function such as sediment building.

We used a large scale in situ warming experiment in a subtropical wetland to increase both marsh and mangrove ecosystem air temperatures. We assessed how 2 years of continuous warming influenced above‐ and below‐ground plant growth and surface elevation relative to sea level.

We found that chronic warming doubled plant height and accelerated the expansion of mangrove into salt marsh vegetation, as indicated by a sixfold greater increase in mangrove cover in warmed plots compared to ambient temperature plots and a corresponding loss in salt marsh cover. Surface elevation gain, a measure of soil‐building capacity, increased due to warming over a 2‐year period and these changes in surface elevation were driven by increased mangrove root production in warmed plots.

Synthesis. Our findings suggest that, in some coastal wetlands, warming can facilitate plant community changes from marsh to mangrove, with corresponding increases in growth that help coastal wetlands to keep pace with sea‐level rise.

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41 thoughts on “Nature always finds a way – coastal wetlands respond positively to global warming

  1. “The record-breaking hurricanes of the past decade in the United States”??

    “4,300 Days Since Last U.S. Major Hurricane Strike
    July 31st, 2017 by Roy W. Spencer, Ph. D.
    Wednesday of this week will mark 4,300 days since the last major hurricane (Category 3 or stronger, 111-129 mph maximum sustained winds) made landfall in the U.S.
    That’s almost 12 years.”

    Not much point reading much further,

    • It beggars belief that anyone can base an article or a press release on such a demonstrable untruth.

      • Interestingly, that ridiculous initial paragraph is not from the paper upon which this article was supposedly based. Here’s the paper:
        https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.13049

        It’s bad enough, with multiple references to projections of accelerated sea-level rise and implausibly large temperature increases, but there’s nothing resembling that ridiculous initial paragraph.

        So who wrote that nonsense? It’s in the phys.org article, here:
        https://phys.org/news/2018-08-mangrove-expansion-climatic-ecosystems-pace.html

        which apparently copied the British Ecological Society article, here:
        https://www.britishecologicalsociety.org/mangroves-climate-change/

        which credits a “Villanova University press release” and gives a “Media Relations Specialist” as the contact.

        The press release doesn’t seem to be on the Villanova.edu web site, but it is probably almost identical to the article that the BES and phys.org ran.

        My best guess is that the ridiculous initial paragraph was written by a non-scientist in the Villanova media relations department, who email-blasted the press release far and wide. The press release was apparently then copied with minimal changes by journalists or “science communicators” (which are pretty much the same thing) at the British Ecological Society, and then by journalists or “science communicators” at phys.org.

        Alternately, the ridiculous initial paragraph could have been added by the British Ecological Society press office.

        I’ve emailed the Villanova media relations contact, asking who wrote that paragraph, and asking them to correct it if it was part of their press release.

        “A lie can travel halfway around the world before the truth can get its boots on.”
        – attributed to Mark Twain and many others, and true even before the Internet

    • Right on, Ron! But if you do read on, as I did out of morbid curiosity, you see that mangroves (and everything else?) adapts by changes and/or migration. So, no pasa nada! Looks like the British Ecological Society should go back to organizing fating contests, or whatever they did before attempting to go mainstream scientists.

    • Ron
      “The record-breaking hurricanes of the past decade in the United States”??
      …Not much point reading much further,

      I didn’t get that far, the first line
           “Sea level rise and extreme weather events have become
           harsh realities for those living along the world’s coasts.”

      was my exit cue.

    • You don’t get it, Ron. Since the study results were not worse than we thought, they had to start the PR with the required genuflection to the orthodox Church of CAGW or risk not getting funded next time they want to waste money. The Church requires that Truth Pravda prevails in all science writing these days.

    • The thing is, they are recordbreaking… in terms of asset damage. But that’s not because of the hurricanes, that’s because those asset values keep growing.

  2. The only thing to consider with this “article” is where to begin with so many false assumptions

    • Assume that they have to put that in to get published. The rest is quite interesting and relevant to threatened coastal communities .

        • Coastal erosion is a threat in many places and even the current small rises in sea level need watching in low lying areas. This research only applies to places with mangroves though, which is a bit limiting.

          • Yes, but where, exactly, are communities being inundated by the horrible 5-8″ per CENTURY of sea level rise? Name a few, at least one.

  3. Well who’d have thought that nature can cope with changing climate and sea-level?

    As Ron says you get to “The record-breaking hurricanes of the past decade in the United States” roll your eyes and stop reading.

  4. Let’s do a study on the theme: Humanity always finds a way – coastal dyke creation responds positively to global sea level rise. Studies of coastal infrastructure projects in the Netherlands show that as global sea level rises coastal dykes get larger and more robust. /sarc

  5. This 2015 article is similar:
    http://phys.org/news/2015-12-coastal-marshes-resilient-sea-level-previously.html

    The key point, from the research reported in the 2015 article, is:

    “…the significant boost in marsh plant productivity associated with elevated levels of atmospheric carbon dioxide will allow marshes to trap more sediment and create more organic soil. This, in turn, will result in increased rates of accretion that will allow marshes to keep up with rising sea levels and may increase the thresholds for marsh drowning by up to 60 percent.”

    Also like this article, the 2015 article starts off with trivially-disproved climate alarmist mythology:

    “Accelerating rates of sea-level rise linked to climate change pose a major threat…”

    Meantime, in the real world, neither hurricanes nor sea-level rise are worsening.

    https://sealevel.info/frequency_12months.png

    https://sealevel.info/1612340_Honolulu_Wismar_Stockholm_vs_CO2_annot3.png

  6. Great grant generating ”science”, based on the sophistry of CC.

    Ron below saved me having to mock their hurricane bs.

  7. Once more, we see temperature selected as a dominant variable of interest, partly because an accident of history left us with a useful quantity of detailed temperature records.
    What if the mangrove vigour arises from more CO2 fertilizer in our air? Is there a feedback that makes more mangrove mass to counter rising seas, rising because more CO2 might be making that air hotter, hence hotter water, hence expanded water, hence higher sea levels?
    Concepts like these are ripe for testing, so the keen detective might say “How many mm of rise are caused by a 1deg C rise in temperature? Alas, I have no idea because nobody wants to state it. Somewhat like the delicacy of stating or not stating a firm climate sensitivity figure like ECS.
    We meet again the poor science problem. Many past famous scientists made their name by calculating useful figures to link parameters together. Like Avogadro’s number. Like the Stefan Boltzmann number. But in today’s climate science world, fame comes from the replacement of a single, useful number by a range of values or, more recently, a probability density function.
    When will we move from thermocentric to broader, openly inquisitive research? It cannot happen too soon.
    Geoff.

    • ““How many mm of rise are caused by a 1deg C rise in temperature?”

      The IPCC prefers to pretend that a 1 deg C rise in ocean temperature would be throughout the whole depth, which makes the effects maximal. Since it is really only the top 100s of meters that would be warming 1 deg C, the effect is rather slight.

      • Besides that, sea level rise due to thermal expansion is local. If the top 700 meters in the middle of the Pacific warm up and expand, does that cause the sea level in the North Atlantic to go up?

  8. Wow. So many incorrect assertions in the first paragraph.
    At least it means that I know I don’t need to read any further.

  9. This paper is actually important because it is off-narrative for CAGW. Everything is supposed to get worse according to CAGW. Plants, animals, and ecosystems aren’t supposed to be able to adapt to a warmer world. The fact that this paper could be written and published is interesting. Maybe it slipped through.

  10. dear researchers – do please visit England and have a look around.
    You will see on signposts dotted around everywhere, places with ‘Carr’ in their name.

    Further and assuming a diet of pasta & wine, trash TV, Prozac and mobile phones hasn’t totally destroyed your social skills, (your paper here suggests it has) you will *meet people* with the family name of Carr.

    Do please find out what a ‘Carr’ is.
    Clue- It is a process that has been happening since time immemorial and possibly where large amounts of coal were laid down in really ancient Earth history.

    btw How’s The Wheel coming along – certainly the move from 3 sides to 4 was a *big* improvement but it’s still not quite right somehow……..

    • Peta,

      And don’t forget about the Carse o’Gowrie on the banks of the silvery Tay in Scotland.
      Alder is a really useful tree.

  11. “The record-breaking hurricanes of the past decade in the United States have led to staggering tolls on coastal infrastructure and communities”

    More likely there has been a staggering increase in coastal infrastructure and communities for the few hurricanes we have had hitting landfall.

    • I would imagine the same in the US-

      “Coastal construction
      How Britain’s shoreline changed in 50 years
      Built-up areas around the UK coast have increased by more than 40%”

      • and then add on

        “Pilkey and Cooper say in a new book, The Last Beach, that sea walls, which are widely believed by many local authorities to protect developments from erosion and sea level rise, in fact lead to the destruction of beaches and sea defences and require constant rebuilding at increasing cost”

        and then blame it on global warming- just peachy.

        • ooops-

          “Storms do not destroy beaches. They change their shape and location, moving sand around to maximise the absorption of wave energy and then recover in the days, months and years to follow,” said Pilkey.”

  12. >>Sea level rise and extreme weather events have become harsh realities for those living along the world’s coasts. The record-breaking hurricanes of the past decade in the United States have led to staggering tolls on coastal infrastructure and communities<<

    Really? B.S. Threshold exceeded, article terminated.

  13. Bangladesh is growing in size, due to the massive amounts of sediment washed down its rivers from the Himalayas. Left to its own devices, mangrove would colonize and stabilise the new deposits, gradually trapping even more sediment until it truly became dry land. Only the country’s poverty gets in the way, leading young families with no land of their own to move onto the new land before it has built up sufficiently to offer protection from tidal surges. Mangroves, instead of being encouraged to protect the coast are cut for firewood. Of course, when they get flooded out it is blamed on cagw. If the developed nations want to make a difference in places like Bangladesh, instead of making meaningless reductions in their fossil fuel usage, they should bring in the equipment to pump more silt onto the land to speed up the process of land reclamation.

  14. There was global warming but it was not due to AGW, it was all due to natural factors which were in a warm mode from the end of the Little Ice Age to year 2017.

    The transition to a colder mode started in late year 2005 and I would say has been pretty much completed by late year 2017.

    This is important because from late 2017 moving forward AGW is no longer going to be able to hi jack natural processes to promote their nonsense theory.

    AGW is over.

    In the late 1970’s we had a climatic shift to warmer due to natural processes, I say at the very least a climate shift similar to that is happening now but to colder .

  15. “We predict that if black mangroves continue to increase in abundance in the northern GOM, estuarine faunal community composition could shift substantially because black mangroves typically colonize shorelines at higher elevations than smooth cordgrass, resulting in habitats of differing complexity and flooding duration.” From Scheffel, W. A., et al. 2018. Tropicalization of the Northern Gulf of Mexico: Impacts of Salt Marsh Transition to Black Mangrove Dominance on Faunal Communities. Estuaries and Coasts, 41(4):1193-1205.

    The word on the ‘mainstream’ marine biological community street is that the whole Gulf will become tropical. There was some thought that this might only move in that direction in the 1950s. All it took was a severe freeze in 1962. Last one was in 1989, but some less severe in places.

    The French didn’t like them when they settled Louisiana because they were difficult to penetrate, now it’s the same concern for whooping cranes. I think I saw a paper saying they are not as good for shrimp, but there are a number of papers with a number of projections, this one also positively physical.

    https://link.springer.com/article/10.1007/s12237-018-0394-7

  16. Mangrove communities on the Merritt Island Wildlife Refuge (AKA Cape Canaveral) are limited by cold weather intrusions. Mangroves are approaching their northern limit in and around the Cape. Cold Fronts in the late 1980s had a severe impact of mangroves in the Refuge.

    The three species of mangroves, red, blacks and whites all have different temperature tolerances.

    However, what the scientists should have been studying is the effects of mosquito impounding on the Refuge which has dramatically changed an entire large ecosystem. High and low marsh were impounded to prevent oviposition of salt marsh mosquitoes. How they worked on the Cape before impounding is truly amazing since mosquito landing rate counts were in the 50+ per minute. At that landing rate repellents do little good.

    From the 1950s until 1970s 90% of the high marsh along the Indian River and Mosquito Lagoon were impounded isolating critical marine nursery habitat from the rest of the system. While some has been reopened through Rotational Impoundment Management, much remain closed. My department funded the Refuge to culvert the impoundments on the Refuge in the 1990s. They bought the culverts, management changed and the culverts were still sitting uninstalled in the late 1990s.

    Bottom line was these scientists did research on habitats that had been significantly altered from their natural condition. Sort of like studying a fallow corn field and making statements about Great Plains grasslands.

    • In the spirit of Monte Python–“You had 50+ per minute!!!” In Louisiana you could never control mosquitoes although they tried with DDT, and impoundments were for waterfowl, favoring vegetation, pros and cons for various species. I had this paper around somewhere, something about residents (mosquito eaters?) suffered when opened to the great benefit of estuarine species. I recall that fishes were “poised to enter.” Louisiana (and a few in Texas) ones were called semi-impoundments because they dammed only about half of the tidal reach, kept the ponds with some water. Should’ve studied is a long list.

      Poulakis, G. R., J. M. Shenker and D. S. Taylor. 2002. Habitat use by fishes after tidal reconnection of an impounded estuarine wetland in the Indian River Lagoon, Florida (USA). Wetlands Ecology and Management. 10:51-69.

      • The important figure in the 50+ was the “+”. Even though covered with rain gear, DEET, etc by the time one leaves such an area your hands, feet and face will actually be swollen. At 50+ count salt marsh mosquitoes don’t seem to care about DEET. The Indian River Lagoon, tidal flow and the impoundments vary dramatically from south to north. Check out a map. Merritt Island is almost completely impounded salt marsh, historical much of it grass marsh. I helped fund a lot of research in fish utilization of impoundments, some opened by RIM other with the dike removed or significantly breeched. I don’t think I know Poulakis but certainly knew Shenker and Taylor. Taylor served on Florida’s Subcommittee on Managed Marshes at the same time I did.

  17. These researchers need to spend a few years in the Great Dismal Swamp.

    Then, they’ll makes the same claims about swamps where temperate zone plants grow instead of “mangroves”.

    Though studying temperate zone swamp life may not hold the same allure that sub-tropical mangroves and warm water hold.

  18. I understand from the fossils that the UK was joined to Europe once before sea level rises separated us from the mainland. This was considerably before fossil fuel use was even remotely significant so to blame in on fossil fuel use is fraud in any language.

  19. I lived just a few hundred feet from the Merritt Island National Wildlife Refuge, it was across the Barge Canal from our marina. My wife and I would dinghy across the canal and walk on the access road there, mostly to watch the feeding spoonbills.
    One thing this study leaves out is that Florida has passed draconian penalties for disturbing mangroves, removing mangroves and has instituted massive mangrove planting programs.
    That said, mangroves love it hot…..they grow better and bigger in the tropics than in Florida. I have sheltered in them from hurricanes on the southern shore of Puerto Rico in Jobos Bay, where the mangroves left only the top of our 52 foot mast exposed to the hurricane force winds .

  20. They needed a 2years ongoing study to find out if “warming can facilitate plant community changes from marsh to mangrove,”

    instead of simply telephoning with colleagues in warmer respective colder environments “how do your marches and mangroves.”

    life is complicated.

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