Updating global coastal wetland areas presented in Davidson and Finlayson (2018)

2019 ◽  
Vol 70 (8) ◽  
pp. 1195 ◽  
Author(s):  
Nick C. Davidson ◽  
C. Max Finlayson
Keyword(s):  
Salt Marshes ◽  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Tidal Flats ◽  
Seagrass Beds ◽  
Wetland Area

Global and regional areas and trends in area of unvegetated tidal flats, salt marshes, mangroves and seagrass beds are updated and corrected from those published in Davidson and Finlayson (2018). The global area of coastal wetlands is now estimated as a minimum of 1.42×106 km2, ~8.9–9.5% of an updated global wetland area of 15.0×106–16.0×106 km2.

scholarly journals Comparison of Qinzhou bay wetland landscape information extraction by three methods

2014 ◽  
Vol XL-4 ◽  
pp. 21-28 ◽  
Author(s):  
X. Chang ◽  
Q. Zhang ◽  
M. Luo ◽  
C. Dong
Keyword(s):  
Coastal Wetlands ◽  
Supervised Classification ◽  
Coastal Wetland ◽  
Object Oriented ◽  
Visual Interpretation ◽  
Wetland Area ◽  
The Third ◽  
Tasseled Cap Transformation ◽  
Qinzhou Bay ◽  
Landscape Information

Wetland ecosystem plays an important role on the environment and sustainable socio-economic development. Based on the TM images in 2010 with a pretreament of Tasseled Cap transformation, three different methods are used to extract the Qinzhou Bay coastal wetlands using Supervised Classification (SC), Decision Trees (DT) and Object -oriented (OO) methods. Firstly coastal wetlands are picked out by artificial visual interpretation as discriminant standard. The result shows that when the same evaluation template used, the accuracy and Kappa coefficient of SC, DT and OO are 92.00 %, 0.8952; 89.00 %, 0.8582; 91.00 %, 0.8848 respectively. The total area of coastal wetland is 218.3 km<sup>2</sup> by artificial visual interpretation, and the extracted wetland area of SC, DT and OO is 219 km<sup>2</sup>, 193.70 km<sup>2</sup>, 217.40 km<sup>2</sup> respectively. The result indicates that SC is in the f irst place, followed by OO approach, and the third DT method when used to extract Qingzhou Bay coastal wetland.

scholarly journals Continuous Change Mapping to Understand Wetland Quantity and Quality Evolution and Driving Forces: A Case Study in the Liao River Estuary from 1986 to 2018

2021 ◽  
Vol 13 (23) ◽  
pp. 4900
Author(s):  
Jianwei Peng ◽  
Shuguang Liu ◽  
Weizhi Lu ◽  
Maochou Liu ◽  
Shuailong Feng ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Driving Forces ◽  
Land Reclamation ◽  
River Estuary ◽  
Tidal Flats ◽  
Liaoning Province ◽  
Coastal Zones ◽  
Continuous Change ◽  
Landsat Images

Coastal wetland ecosystems, one of the most important ecosystems in the world, play an important role in regulating climate, sequestering blue carbon, and maintaining sustainable development of coastal zones. Wetland landscapes are notoriously difficult to map with satellite data, particularly in highly complex, dynamic coastal regions. The Liao River Estuary (LRE) wetland in Liaoning Province, China, has attracted major attention due to its status as Asia’s largest coastal wetland, with extensive Phragmites australis (reeds), Suaeda heteroptera (seepweed, red beach), and other natural resources that have been continuously encroached upon by anthropogenic land-use activities. Using the Continuous Change Detection and Classification (CCDC) algorithm and all available Landsat images, we mapped the spatial–temporal changes of LRE coastal wetlands (e.g., seepweed, reed, tidal flats, and shallow marine water) annually from 1986 to 2018 and analyzed the changes and driving forces. Results showed that the total area of coastal wetlands in the LRE shrank by 14.8% during the study period. The tidal flats were the most seriously affected type, with 45.7% of its total area lost. One of the main characteristics of wetland change was the concurrent disappearance and emergence of wetlands in different parts of the LRE, creating drastically different mixtures of wetland quality (e.g., wetland age composition) in addition to area change. The reduction and replacement/translocation of coastal wetlands were mainly caused by human activities related to urbanization, tourism, land reclamation, and expansion of aquaculture ponds. Our efforts in mapping annual changes of wetlands provide direct, specific, and spatially explicit information on rates, patterns, and causes of coastal wetland change, both in coverage and quality, so as to contribute to the effective plans and policies for coastal management, preservation, and restoration of coastal ecosystem services.

Fish Habitat: Essential Fish Habitat and Rehabilitation

1999 ◽  
Keyword(s):  
United States ◽  
Salt Marsh ◽  
Marine Fish ◽  
Salt Marshes ◽  
Coastal Wetlands ◽  
Life Histories ◽  
Coastal Wetland ◽  
Fish Habitat ◽  
Northeastern United States ◽  
Fishery Habitat

<em>Abstract</em> .—The importance of coastal wetlands to a large number of commercially important marine fish species for spawning, nursery, and foraging habitat is a commonly held belief. Few studies to substantiate this belief have been conducted in the northeastern United States. This paper examines in detail the life histories and habitat requirements of three species of fish commonly found in salt marshes in the northeastern United States. The results indicate that valuable commercial and recreational species of fish and their prey require coastal wetlands as habitat during their life cycles in New England. Coastal wetland restoration projects will increase the abundance of wetland habitat types required by commercial and recreational species of marine fish. The restoration of the salt marsh within the Galilee Bird Sanctuary in Narragansett, Rhode Island is used as case study. When enhancement of fishery habitat value is a goal of a restoration project, the project should incorporate certain design features. However, the designers of many salt-marsh restoration projects assume that reestablishment of salt-marsh vegetation will result in recolonization by other species of animals.

scholarly journals Endophytic Fungi of Emersed Halophytes in River Deltas and Tidal Flats of the Korean Ramsar Wetlands

2021 ◽  
Vol 9 (4) ◽  
pp. 430
Author(s):  
Jong-Myong Park ◽  
Ji-Won Hong ◽  
Young-Hyun You ◽  
Jong-Guk Kim
Keyword(s):  
Endophytic Fungi ◽  
Salt Marshes ◽  
Tidal Flat ◽  
Coastal Wetlands ◽  
Morphological Diversity ◽  
Diversity Indices ◽  
Culture Collection ◽  
Tidal Flats ◽  
River Deltas ◽  
Distinct Distribution

This study aimed to obtain information on the diversity and distribution of the endophytic fungi in Ramsar wetlands. Vast salt marshes in Suncheon Bay, Korea, are formed by two types of ecotones (tidal flats and deltas) that are supported by the emersed halophytes Phragmites australis and Suaeda japonica. Overall, 324 endophytes were isolated from P. australis (six sampling points in the delta and five in the tidal flats) and S. japonica (six in tidal flats). Margalef’s, Menhinick’s, Shannon’s, and Simpson’s diversity indices significantly varied among the ecotones. In particular, higher variance in diversity value and unevenness was observed in the delta marsh compared with the tidal flat marsh. Further, morphological diversity in the delta salt marsh was 1.8 times higher than that of the tidal flat. Comprising several dominant genera (Aspergillus, Cladosporium, and Penicillium), Epicoccum, Paraconiothyrium, Septoriella, and Talaromyces were widely distributed regardless of the aquatic conditions or halophyte species. This study highlights the distinct distribution and diversity of marine endophytes in various ecotones that can physically protect the coastal areas. This data is of much value to secure a national culture collection for future restoration of the coastal wetlands and their ecosystems.

China's coastal-wetland change analysis based on high-resolution remote sensing

2020 ◽  
Vol 71 (9) ◽  
pp. 1161
Author(s):  
Yin Gao ◽  
Lijuan Cui ◽  
Jianjun Liu ◽  
Wei Li ◽  
Yinru Lei
Keyword(s):  
High Resolution ◽  
Salt Marshes ◽  
Coastal Wetlands ◽  
Large Scale ◽  
Coastal Wetland ◽  
Complex Structure ◽  
Hangzhou Bay ◽  
Bohai Bay ◽  
Change Analysis ◽  
High Productivity

Coastal wetlands not only have abundant biodiversity and high productivity, but they also play an irreplaceable and important role in regional ecosystems. Because of the complex structure and dynamic characteristics of coastal wetlands, it is difficult to observe the spatial changes of coastal wetlands on a large scale and improve data reliability. In this study, a spatially constrained manual-interpretation method based on nationwide high-resolution images in 2017 was adopted to extract China’s coastal wetland distribution, and, then, the second national wetland-survey data from 2011 were used as a baseline for change analysis. The results showed that under the influence of natural conditions and human activities, China’s coastal wetlands have decreased in distribution in the past 6 years. The situation of coastal wetland reclamation is critical, and the hotspot regions are mainly distributed in Bohai Bay, middle of Jiangsu province and Hangzhou Bay. Farming reclamation is another factor that occupies coastal wetlands in China, and main occupied wetlands are mudflats, shallow sea, tidal flats, intertidal salt marshes and estuarine waters. Tide is the main factor affecting extraction of wetlands, the spatially constrained method had a positive effect on wetland detection, and has potential to improve automatic algorithms of complex coastal wetlands.

scholarly journals Coastal Wetlands Effectively Sequester “Blue Carbon”

Eos ◽  
2017 ◽  
Author(s):  
Sarah Witman
Keyword(s):  
Carbon Storage ◽  
Salt Marshes ◽  
Coastal Wetlands ◽  
Blue Carbon ◽  
Seagrass Beds ◽  
Mangrove Forests

Mangrove forests, salt marshes, seagrass beds, and the like are carbon storage treasure troves.

scholarly journals Coastal wetlands in Lianyungang, Jiangsu Province, China: probably the most important site globally for the Asian Dowitcher (Limnodromus semipalmatus)

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ziyou Yang ◽  
Jing Li ◽  
Yongxiang Han ◽  
Chris J. Hassell ◽  
Kar-Sin Katherine Leung ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Migratory Bird ◽  
Jiangsu Province ◽  
Bohai Bay ◽  
High Concentration ◽  
Human Disturbances ◽  
Stopover Site ◽  
Stochastic Events ◽  
Global Population

Abstract Background Despite an increasing number of surveys and a growing interest in birdwatching, the population and distribution of Asian Dowitcher (Limnodromus semipalmatus), a species endemic to the East Asian–Australasian and Central Asian Flyways, remains poorly understood, and published information about the species is largely outdated. In boreal spring 2019, over 22,432 Asian Dowitchers were recorded in a coastal wetland at Lianyungang, Jiangsu Province, China, constituting 97.5% of its estimated global population. Methods In 2019 and 2020, we conducted field surveys at Lianyungang to determine the numbers of Asian Dowitchers using the area during both southward and northward migrations. We also assessed the distribution and abundance of Asian Dowitchers elsewhere along the China coast by searching literature and consulting expert opinion. Results The coastal wetlands of Lianyungang are the most important stopover site for Asian Dowitchers during both northward and southward migrations; they supported over 90% of the estimated global population during northward migration in two consecutive years (May 2019 and 2020). This area also supported at least 15.83% and 28.42% (or 30.74% and 53.51% using modelled estimates) of the global population during southward migration in 2019 and 2020 respectively. Coastal wetlands in the west and north of Bohai Bay also have been important stopover sites for the species since the 1990s. Although comprehensive, long-term monitoring data are lacking, available evidence suggests that the population of the species may have declined. Conclusions The high concentration of Asian Dowitchers at Lianyungang during migration means the species is highly susceptible to human disturbances and natural stochastic events. The coastal wetlands of Lianyungang should be protected and potentially qualify for inclusion in China’s forthcoming nomination for World Heritage listing of Migratory Bird Sanctuaries along the Coast of Yellow Sea-Bohai Gulf of China (Phase II) in 2023. Additional research is needed to understand Asian Dowitchers’ distribution and ecology, as well as why such a high proportion of their population rely on the Lianyungang coast.

Hydrogeochemistry and Water Balance in the Coastal Wetland Area of “Biviere di Gela,” Sicily, Italy

2006 ◽  
Vol 178 (1-4) ◽  
pp. 179-193 ◽  
Author(s):  
Emanuela Manno ◽  
Massimo Vassallo ◽  
Daniela Varrica ◽  
Gaetano Dongarrà ◽  
Sergio Hauser
Keyword(s):  
Water Balance ◽  
Coastal Wetland ◽  
Wetland Area

scholarly journals Prediction Potential of Remote Sensing-Related Variables in the Topsoil Organic Carbon Density of Liaohekou Coastal Wetlands, Northeast China

2021 ◽  
Vol 13 (20) ◽  
pp. 4106
Author(s):  
Shuai Wang ◽  
Mingyi Zhou ◽  
Qianlai Zhuang ◽  
Liping Guo
Keyword(s):  
Remote Sensing ◽  
Organic Carbon ◽  
Coastal Wetlands ◽  
Environmental Variables ◽  
Northeast China ◽  
Vegetation Index ◽  
Coastal Wetland ◽  
Wetland Ecosystems ◽  
Flat Terrain ◽  
Soc Density

Wetland ecosystems contain large amounts of soil organic carbon. Their natural environment is often both at the junction of land and water with good conditions for carbon sequestration. Therefore, the study of accurate prediction of soil organic carbon (SOC) density in coastal wetland ecosystems of flat terrain areas is the key to understanding their carbon cycling. This study used remote sensing data to study SOC density potentials of coastal wetland ecosystems in Northeast China. Eleven environmental variables including normalized difference vegetation index (NDVI), difference vegetation index (DVI), soil adjusted vegetation index (SAVI), renormalization difference vegetation index (RDVI), ratio vegetation index (RVI), topographic wetness index (TWI), elevation, slope aspect (SA), slope gradient (SG), mean annual temperature (MAT), and mean annual precipitation (MAP) were selected to predict SOC density. A total of 193 soil samples (0–30 cm) were divided into two parts, 70% of the sampling sites data were used to construct the boosted regression tree (BRT) model containing three different combinations of environmental variables, and the remaining 30% were used to test the predictive performance of the model. The results show that the full variable model is better than the other two models. Adding remote sensing-related variables significantly improved the model prediction. This study revealed that SAVI, NDVI and DVI were the main environmental factors affecting the spatial variation of topsoil SOC density of coastal wetlands in flat terrain areas. The mean (±SD) SOC density of full variable models was 18.78 (±1.95) kg m−2, which gradually decreased from northeast to southwest. We suggest that remote sensing-related environmental variables should be selected as the main environmental variables when predicting topsoil SOC density of coastal wetland ecosystems in flat terrain areas. Accurate prediction of topsoil SOC density distribution will help to formulate soil management policies and enhance soil carbon sequestration.

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