Salt marsh width positively affects the occurrence of Least and Pectoral Sandpipers in the St. Lawrence River Estuary during fall migration

2021 ◽  
Vol 135 (2) ◽  
pp. 192-202
Author(s):  
Yves Turcotte ◽  
Jean-François Lamarre ◽  
Éliane Duchesne ◽  
Joël Bêty
Keyword(s):  
Climate Change ◽  
Salt Marsh ◽  
Salt Marshes ◽  
Generalized Estimating Equations ◽  
River Estuary ◽  
Effective Management ◽  
Vegetation Zone ◽  
Vegetation Zones ◽  
Coastal Squeeze ◽  
St Lawrence River

Salt marshes are vulnerable to climate change-associated sea-level rise and storm-induced surges. Their degradation will likely affect shorebirds relying on this ecosystem. Least Sandpiper (Calidris minutilla) and Pectoral Sandpiper (Calidris melanotos) migrating along coastline habitats typically use salt marshes to rest and replenish their body reserves. Our objective was to test if width of the different vegetation zones within salt marshes affects the occurrence of Least and Pectoral Sandpipers stopping along the St. Lawrence River Estuary, Quebec, Canada, during fall migration. We established 26 survey sites, each 600 m in length, along the shoreline. Shorebird surveys were conducted in 2011 and 2012. We characterized salt marshes by measuring the width of each vegetation zone (lower marsh and upper marsh). We analyzed shorebird presence/not detected data with generalized estimating equations to test the predictions that occurrence of Least Sandpipers and Pectoral Sandpipers increases with width of both the lower and upper marsh. Upper marsh width was positively associated with probability of occurrence in each species. Our results highlight the importance of protecting the integrity of salt marshes for these two species. In the St. Lawrence River Estuary, where landward migration of salt marshes is no longer possible (coastal squeeze), effective management of shorelines is much needed. Otherwise, salt marshes and these two species could be locally jeopardized.

Establishing the value of a salt marsh as a potential benchmark: vegetation surveys and paleoecological analyses as assessment tools

Botany ◽  
2013 ◽  
Vol 91 (11) ◽  
pp. 774-785 ◽  
Author(s):  
Myosotis Bourgon Desroches ◽  
Martin Lavoie ◽  
Claude Lavoie
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
River Estuary ◽  
Assessment Tools ◽  
Vegetation Surveys ◽  
Plant Assemblages ◽  
A Site ◽  
Very High ◽  
St Lawrence River

Identifying tidal salt marshes as priority sites for conservation or restoration remains a challenge, as several sites are so severely degraded that allocating financial resources for their protection would be questionable. The decision-making process could nevertheless be facilitated by comparing species assemblages and the dynamics and (or) ecological functions of a site with an ecological benchmark, i.e., a tidal marsh that remains free from anthropogenic disturbances. We used plant surveys and plant macrofossil and pollen analyses for evaluating the benchmark potential of the Pointe-aux-Épinettes marsh, a protected salt marsh of the St. Lawrence River estuary (Canada) and one of the last salt marshes that could potentially be a benchmark along the estuary. Historical evidence indicated that the forests surrounding the marsh were converted into agricultural lands circa 1850. Nevertheless, this land-use change had little impact on the marsh. The long-term impacts of trampling and grazing by livestock on the vegetation were negligible. Macrofossil analyses indicated that the plant assemblages were dynamic, but past and current vegetation assemblages are representative of those characterizing an undisturbed salt marsh, with a very high proportion of native wetland species. In a context where truly undisturbed salt marshes are extremely rare ecosystems, our study indicates that the Pointe-aux-Épinettes plant assemblages could be used as benchmarks against which the condition of the vegetation of other salt marshes in northeastern North America could be evaluated.

scholarly journals A 1900 Year Sediment Record Suggests Recent Establishment of Black Mangrove (Avicennia Germinans) Stands within a Salt Marsh in St. Augustine, Florida, USA

Quaternary ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Jessica Chamberlin ◽  
Camryn Soehnlein ◽  
Jason Evans ◽  
Benjamin Tanner
Keyword(s):  
Climate Change ◽  
Salt Marsh ◽  
Salt Marshes ◽  
Stable Carbon Isotope ◽  
Potential Effect ◽  
Avicennia Germinans ◽  
Ice Age ◽  
Mangrove Expansion ◽  
Cold Events ◽  
Extreme Cold

Salt marshes and mangroves are currently being affected by rising temperatures. Mangroves thrive below −29° N latitude in Florida, USA, and have a low tolerance for extreme cold events, whereas salt marshes dominate further north. One potential effect of climate change is a reduction in the frequency of extreme cold events, which may lead to mangrove expansion into salt marsh systems. Our research identified sediment proxy indicators of salt marsh and mangrove environments. These indicators were applied to soil cores from intertidal wetlands near the current northern limit of mangrove presence on the east coast of Florida, to determine if mangrove expansion into salt marsh environments has precedence in the deeper past. Our findings suggest that mangrove and salt marsh sediments can be distinguished using a combination of stable carbon isotope ratios of sedimentary organic matter and macroscopic plant fragments, and our results showed that a mangrove stand that we cored established only recently. This result is consistent with other work in the southeastern United States that suggests that mangroves established at the current boreal limit only recently after the end of the Little Ice Age, and that the current mangrove expansion may be fueled by anthropogenic climate change.

scholarly journals Climate-driven regime shifts in a mangrove–salt marsh ecotone over the past 250 years

2019 ◽  
Vol 116 (43) ◽  
pp. 21602-21608 ◽  
Author(s):  
Kyle C. Cavanaugh ◽  
Emily M. Dangremond ◽  
Cheryl L. Doughty ◽  
A. Park Williams ◽  
John D. Parker ◽  
...  
Keyword(s):  
Climate Change ◽  
Salt Marsh ◽  
Salt Marshes ◽  
Minimum Temperature ◽  
Daily Minimum Temperature ◽  
Climate Projections ◽  
Climate Data ◽  
The Past ◽  
Decadal Scale ◽  
Annual Minimum Temperature

Climate change is driving the tropicalization of temperate ecosystems by shifting the range edges of numerous species poleward. Over the past few decades, mangroves have rapidly displaced salt marshes near multiple poleward mangrove range limits, including in northeast Florida. It is uncertain whether such mangrove expansions are due to anthropogenic climate change or natural climate variability. We combined historical accounts from books, personal journals, scientific articles, logbooks, photographs, and maps with climate data to show that the current ecotone between mangroves and salt marshes in northeast Florida has shifted between mangrove and salt marsh dominance at least 6 times between the late 1700s and 2017 due to decadal-scale fluctuations in the frequency and intensity of extreme cold events. Model projections of daily minimum temperature from 2000 through 2100 indicate an increase in annual minimum temperature by 0.5 °C/decade. Thus, although recent mangrove range expansion should indeed be placed into a broader historical context of an oscillating system, climate projections suggest that the recent trend may represent a more permanent regime shift due to the effects of climate change.

scholarly journals Climate Change Impacts on Salt Marsh Blue Carbon, Nitrogen and Phosphorous Stocks and Ecosystem Services

2021 ◽  
Vol 11 (4) ◽  
pp. 1969
Author(s):  
Bernardo Duarte ◽  
João Carreiras ◽  
Isabel Caçador
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Salt Marsh ◽  
Salt Marshes ◽  
Floristic Composition ◽  
Blue Carbon ◽  
Physiological Characteristics ◽  
Human Populations ◽  
Global Changes ◽  
Species Response

Salt marshes are valuable ecosystems, as they provide food, shelter, and important nursery areas for fish and macroinvertebrates, and a wide variety of ecosystem services for human populations. These ecosystem services heavily rely on the floristic composition of the salt marshes with different species conferring different service values and different adaptation and resilience capacities towards ecosystem stressors. Blue carbon, nitrogen, and phosphorous stocks are no exception to this, and rely on the interspecific differences in the primary production metabolism and physiological traits. Furthermore, these intrinsic physiological characteristics also modulate the species response to any environmental stressor, such as the ones derived from ongoing global changes. This will heavily shape transitional ecosystem services, with significant changes of the ecosystem value of the salt marshes in terms of cultural, provisioning, regulating, and supporting ecosystem services, with a special emphasis on the possible alterations of the blue carbon, nitrogen, and phosphorous stocks retained in these key environments. Thus, the need to integrate plant physiological characteristics and feedbacks towards the expected climate change-driven stressors becomes evident to accurately estimate the ecosystem services of the salt marsh community, and transfer these fundamental services into economic assets, for a fluid communication of the ecosystems value to stakeholders, decision and policy makers, and environmental management entities.

Fire and drought experiments in northern wetlands: a climate change analogue

1991 ◽  
Vol 69 (9) ◽  
pp. 1991-1997 ◽  
Author(s):  
John C. Hogenbirk ◽  
Ross W. Wein
Keyword(s):  
Climate Change ◽  
Native Species ◽  
Plant Cover ◽  
Stem Density ◽  
Percent Cover ◽  
Drought Treatment ◽  
Vegetation Zone ◽  
Vegetation Zones ◽  
Seasonally Flooded ◽  
Eurasian Species

Drought and fire, which may increase in frequency and severity because of global warming, were simulated in mid-boreal wetlands by transplanting soil blocks upslope to a lower water table and by prescribed burns. In the 2 years after treatments were applied to seasonally flooded vegetation zones in the Peace–Athabasca Delta, Alberta, the drought treatment did not significantly change stem density and height of the dominant hygrophytes Calamagrostis canadensis and Carex atherodes. Dicotyledonous species' density and richness increased 3- to 36-fold on soil blocks moved upslope to the driest vegetation zone relative to unmoved soil blocks. The percent cover of native dicotyledonous species was unaffected but that of xerophytic Eurasian species, Sonchus arvensis and Cirsium arvense, increased 5- to 13-fold after drought treatment. Fire, particularly the deepest burn, reduced graminoid density and height up to 90%. Dicotyledon density, but not richness, was generally higher after fire. Plant cover was unaffected by fire but Eurasian species' cover was still 3- to 15-fold greater than that of native species. Seasonally flooded vegetation zones will likely be shifted from flood-driven dynamics with cool and moist environmental conditions towards drought- and fire-driven dynamics with warmer and drier conditions. It is hypothesized that, under these climate change conditions, Eurasian species might dominate early successional communities in mid-boreal wetlands. Key words: drought, fire, greenhouse effect, Peace–Athabasca Delta, wetland vegetation, Wood Buffalo National Park.

Improving Predictions of Salt Marsh Evolution Through Better Integration of Data and Models

2020 ◽  
Vol 12 (1) ◽  
pp. 389-413 ◽  
Author(s):  
Patricia L. Wiberg ◽  
Sergio Fagherazzi ◽  
Matthew L. Kirwan
Keyword(s):  
Climate Change ◽  
Salt Marsh ◽  
Salt Marshes ◽  
Human Activities ◽  
Observational Studies ◽  
Future Change ◽  
Coastal Landscapes

Salt marshes are recognized as valuable resources that are threatened by climate change and human activities. Better management and planning for these ecosystems will depend on understanding which marshes are most vulnerable, what is driving their change, and what their future trajectory is likely to be. Both observations and models have provided inconsistent answers to these questions, likely in part because of comparisons among sites and/or models that differ significantly in their characteristics and processes. Some of these differences almost certainly arise from processes that are not fully accounted for in marsh morphodynamic models. Here, we review distinguishing properties of marshes, important processes missing from many morphodynamic models, and key measurements missing from many observational studies. We then suggest some comparisons between models and observations that will provide critical tests and insights to improve our ability to forecast future change in these coastal landscapes.

Urbanization impacts on production and recruitment of Fundulus heteroclitus in salt marsh creeks

2020 ◽  
Vol 645 ◽  
pp. 187-204
Author(s):  
PJ Rudershausen ◽  
JA Buckel
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Fundulus Heteroclitus ◽  
Multiple Factor Analysis ◽  
Southeastern Usa ◽  
Density Dependent ◽  
Dependent Relationship ◽  
Juvenile Abundance ◽  
The Relationship ◽  
Throw Trap

It is unclear how urbanization affects secondary biological production in estuaries in the southeastern USA. We estimated production of larval/juvenile Fundulus heteroclitus in salt marsh areas of North Carolina tidal creeks and tested for factors influencing production. F. heteroclitus were collected with a throw trap in salt marshes of 5 creeks subjected to a range of urbanization intensities. Multiple factor analysis (MFA) was used to reduce dimensionality of habitat and urbanization effects in the creeks and their watersheds. Production was then related to the first 2 dimensions of the MFA, month, and year. Lastly, we determined the relationship between creek-wide larval/juvenile production and abundance from spring and abundance of adults from autumn of the same year. Production in marsh (g m-2 d-1) varied between years and was negatively related to the MFA dimension that indexed salt marsh; higher rates of production were related to creeks with higher percentages of marsh. An asymptotic relationship was found between abundance of adults and creek-wide production of larvae/juveniles and an even stronger density-dependent relationship was found between abundance of adults and creek-wide larval/juvenile abundance. Results demonstrate (1) the ability of F. heteroclitus to maintain production within salt marsh in creeks with a lesser percentage of marsh as long as this habitat is not removed altogether and (2) a density-dependent link between age-0 production/abundance and subsequent adult recruitment. Given the relationship between production and marsh area, natural resource agencies should consider impacts of development on production when permitting construction in the southeastern USA.

Effects of climate change and fishing on the Pearl River Estuary ecosystem and fisheries

2019 ◽  
Vol 29 (4) ◽  
pp. 861-875
Author(s):  
Zeyu Zeng ◽  
William W. L. Cheung ◽  
Shiyu Li ◽  
Jiatang Hu ◽  
Ying Wang
Keyword(s):  
Climate Change ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
The Pearl River Estuary ◽  
The Pearl River

scholarly journals Coastal green infrastructure to mitigate coastal squeeze

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Valeria Chávez ◽  
Debora Lithgow ◽  
Miguel Losada ◽  
Rodolfo Silva-Casarin
Keyword(s):  
Climate Change ◽  
Green Infrastructure ◽  
Risk Evaluation ◽  
Good Practices ◽  
Goods And Services ◽  
Natural Processes ◽  
Holistic Management ◽  
Coastal Squeeze ◽  
Key Concepts ◽  
Coastal Risk

AbstractInfrastructure is necessary to protect and provide the goods and services required by humans. As coastal green infrastructure (CGI) aims to respect and work with natural processes, it is a feasible response to mitigate or avoid the consequences of coastal squeeze. The concept of CGI is receiving increased attention of late due to the challenges facing us, such as climate change, population growth and the overexploitation of natural resources on the coast. Terms which may be applied to encourage the construction of infrastructure, or to minimize the responsibility for poorly made decisions, often induce misunderstanding. In this paper, the concept of CGI and its use in solving coastal problems is reordered. Four categories are proposed, according to the degree of naturalness of the project: Nature reclamation, Engineered ecosystems, Ecologically enhanced engineering, and De-engineering/Relocation. Existing coastal risk evaluation frameworks can be used to design many types of CGI. Key concepts, challenges and good practices for the holistic management of coastal squeeze are presented from the analysis of successful and unsuccessful CGI projects worldwide.

scholarly journals Topological and Morphological Controls on Morphodynamics of Salt Marsh Interiors

2021 ◽  
Vol 9 (3) ◽  
pp. 311
Author(s):  
Ben R. Evans ◽  
Iris Möller ◽  
Tom Spencer
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
East Coast ◽  
Marsh Surface ◽  
Coastal Environments ◽  
Coastal System ◽  
Morphological Segmentation ◽  
The Usa ◽  
The Uk ◽  
Over Time

Salt marshes are important coastal environments and provide multiple benefits to society. They are considered to be declining in extent globally, including on the UK east coast. The dynamics and characteristics of interior parts of salt marsh systems are spatially variable and can fundamentally affect biotic distributions and the way in which the landscape delivers ecosystem services. It is therefore important to understand, and be able to predict, how these landscape configurations may evolve over time and where the greatest dynamism will occur. This study estimates morphodynamic changes in salt marsh areas for a regional domain over a multi-decadal timescale. We demonstrate at a landscape scale that relationships exist between the topology and morphology of a salt marsh and changes in its condition over time. We present an inherently scalable satellite-derived measure of change in marsh platform integrity that allows the monitoring of changes in marsh condition. We then demonstrate that easily derived geospatial and morphometric parameters can be used to determine the probability of marsh degradation. We draw comparisons with previous work conducted on the east coast of the USA, finding differences in marsh responses according to their position within the wider coastal system between the two regions, but relatively consistent in relation to the within-marsh situation. We describe the sub-pixel-scale marsh morphometry using a morphological segmentation algorithm applied to 25 cm-resolution maps of vegetated marsh surface. We also find strong relationships between morphometric indices and change in marsh platform integrity which allow for the inference of past dynamism but also suggest that current morphology may be predictive of future change. We thus provide insight into the factors governing marsh degradation that will assist the anticipation of adverse changes to the attributes and functions of these critical coastal environments and inform ongoing ecogeomorphic modelling developments.

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