Beyond 2100: Elevation capital disguises salt marsh vulnerability to sea-level rise in Georgia, USA

Differential sea-level change in formerly glaciated areas is predicted owing to variability in extent and timing of glacial coverage. Newfoundland is situated close to the margin of the former Laurentide ice sheet, and the orientation of the shoreline affords the opportunity to investigate variable rates and magnitudes of sea-level change. Analysis of salt-marsh records at four sites around the island yields late Holocene sea-level trends. These trends indicate differential sea-level change in recent millennia. A north–south geographic trend reflects submergence in the south, very slow sea-level rise in the northeast, and a recent transition from falling to rising sea-level at the base of the Northern Peninsula. This variability is best explained as a continued isostatic response to deglaciation.

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Ecophysiological response of native and exotic salt marsh vegetation to waterlogging and salinity: Implications for the effects of sea-level rise

Scientific Reports ◽

10.1038/s41598-017-18721-z ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 14

Author(s):

Shi-Hua Li ◽

Zhen-Ming Ge ◽

Li-Na Xie ◽

Wei Chen ◽

Lin Yuan ◽

...

Keyword(s):

Salt Marsh ◽

Sea Level Rise ◽

Sea Level ◽

Salt Marsh Vegetation ◽

Marsh Vegetation ◽

Ecophysiological Response

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A foraminiferal proxy record of 20th century sea-level rise in the Manukau Harbour, New Zealand

Marine and Freshwater Research ◽

10.1071/mf11208 ◽

2012 ◽

Vol 63 (4) ◽

pp. 370 ◽

Cited By ~ 10

Author(s):

Hugh R. Grenfell ◽

Bruce W. Hayward ◽

Ritsuo Nomura ◽

Ashwaq T. Sabaa

Keyword(s):

New Zealand ◽

Salt Marsh ◽

Sea Level Rise ◽

Sea Level ◽

20Th Century ◽

Tide Gauge ◽

Sediment Accumulation ◽

Proxy Record ◽

Tide Gauge Record ◽

Tidal Salt Marsh

The present study aimed to extract a sea-level history from northern New Zealand salt-marsh sediments using a foraminiferal proxy, and to extend beyond the longest nearby tide-gauge record. Transects through high-tidal salt marsh at Puhinui, Manukau Harbour, Auckland, New Zealand, indicate a zonation of dominant foraminifera in the following order (with increasing elevation): Ammonia spp.–Elphidium excavatum, Ammotium fragile, Miliammina fusca, Haplophragmoides wilberti–Trochammina inflata, Trochamminita salsa–Miliammina obliqua. The transect sample faunas are used as a training set to generate a transfer function for estimating past tidal elevations in two short cores nearby. Heavy metal, 210Pb and 137Cs isotope analyses provide age models that indicate 35 cm of sediment accumulation since ~1890 AD. The first proxy-based 20th century rates of sea-level rise from New Zealand’s North Island at 0.28 ± 0.05 cm year–1 and 0.33 ± 0.07 cm year–1 are estimated. These are faster than the nearby Auckland tide gauge for the same interval (0.17 ± 0.1 cm year–1), but comparable to a similar proxy record from southern New Zealand (0.28 ± 0.05 cm year–1) and to satellite-based observations of global sea-level rise since 1993 (0.31 ± 0.07 cm year–1).

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Venice lagoon salt marsh vulnerability and halophytic vegetation vertical migration in response to sea level rise

10.5194/egusphere-egu2020-14404 ◽

2020 ◽

Author(s):

Zhicheng Yang ◽

Sonia Silvestri ◽

Marco Marani ◽

Andrea D’Alpaos

Keyword(s):

Salt Marsh ◽

Sea Level Rise ◽

Sea Level ◽

Salt Marshes ◽

Current Knowledge ◽

Venice Lagoon ◽

Sea Level Changes ◽

Human Pressure ◽

Sea Levels ◽

Vegetation Species

<p>Salt marshes are biogeomorphic systems that provide important ecosystem services such as carbon sequestration and prevention of coastal erosion. These ecosystems are, however, threatened by increasing sea levels and human pressure. Improving current knowledge of salt-marsh response to changes in the environmental forcing is a key step to understand and predict salt-marsh evolution, especially under accelerated sea level rise scenarios and increasing human pressure. Towards this goal, we have analyzed field observations of marsh topographic changes and halophytic vegetation distribution with elevation collected over 20 years (between 2000 and 2019) in a representative marsh in the Venice lagoon (Italy).</p><p>Our results suggest that: 1) on average, marsh elevation with respect to local mean sea level decreased , (i.e. the surface accretion rate was lower than the rate of sea level rise); 2) elevational frequency distributions are characteristic for different halophytic vegetation species, highlighting different ecological realized niches that change in time; 3) although the preferential elevations at which different species have changed in time, the sequence of vegetation species with increasing soil elevation was preserved and simply shifted upward; 4) we observed different vegetation migration rates for the different species, suggesting that the migration process is species-specific. In particular, vegetation species colonizing marsh edges (Juncus and Inula) migrated faster facing to changes in sea levels than Limonium and Spartina , while Sarcocornia was characterized by delayed migration in response to sea level changes. These results bear significant implications for long-term biogeomorphic evolution of tidal environments.</p>

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