scholarly journals Wetlands of International Importance: Status, Threats, and Future Protection

2019 ◽  
Vol 16 (10) ◽  
pp. 1818 ◽  
Author(s):  
Ting Xu ◽  
Baisha Weng ◽  
Denghua Yan ◽  
Kun Wang ◽  
Xiangnan Li ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
Wetland Management ◽  
Impact Factors ◽  
Natural Wetland ◽  
Land Area ◽  
Large Space ◽  
International Importance ◽  
Natural Wetlands ◽  
Impact On Biodiversity ◽  
Lake Wetlands

The 2303 Wetlands of International Importance distribute unevenly in different continents. Europe owns the largest number of sites, while Africa has the largest area of sites. More than half of the sites are affected by three or four impact factors (55%). The most significant impact factors are pollution (54%), biological resources use (53%), natural system modification (53%), and agriculture and aquaculture (42%). The main affected objects are land area and environment of the wetlands, occurred in 75% and 69% of the sites, respectively. The types most affected by land area occupation are river wetlands and lake wetlands, the types with the greatest impact on environment are marine/coastal wetlands and river wetlands, the type with the greatest impact on biodiversity is river wetlands, the types most affected by water resources regulation are marsh wetlands and river wetlands, and the types most affected by climate change are lake wetlands and marine/coastal wetlands. About one-third of the wetland sites have been artificially reconstructed. However, it is found that the proportions of natural wetland sites not affected or affected by only one factor are generally higher than that of wetland sites both containing natural wetlands and human-made wetlands, while the proportions of wetland sites both containing natural wetlands and human-made wetlands affected by three or four factors are generally higher than that of natural wetland sites. Wetland sites in the UK and Ireland are least affected among all countries. Wetland management plans in different regions still have large space for improvement, especially in Africa and Asia. The protection and restoration of global wetlands can be carried out in five aspects, including management and policy, monitoring, restoration, knowledge, and funding.

Change in biomass of benthic and planktonic algae along a disturbance gradient for 24 Great Lakes coastal wetlands

2003 ◽  
Vol 60 (6) ◽  
pp. 676-689 ◽  
Author(s):  
Sheila A McNair ◽  
Patricia Chow-Fraser
Keyword(s):  
Water Quality ◽  
Great Lakes ◽  
Chlorophyll A ◽  
Total Variation ◽  
Coastal Wetlands ◽  
Phytoplankton Biomass ◽  
Wetland Management ◽  
Percent Cover ◽  
Planktonic Algae ◽  
Wide Range

We quantified the chlorophyll a content of planktonic algae and benthic algae in periphyton on acrylic rods and in epiphyton growing on macrophytes in 24 coastal wetlands in all five Laurentian Great Lakes. Sites were selected to represent a wide range of environmental conditions ranging from nutrient-poor, clear-water marshes with abundant macrophytes to nutrient-enriched, turbid systems devoid of aquatic vegetation. Water quality and species and percent cover of submergent macrophytes were measured in each wetland. Principal components analysis (PCA) showed that total phosphorus, turbidity, and suspended solids, variables associated with human-induced degradation, were most strongly correlated with PC axis 1 (PC1), accounting for 69% of the total variation. The PC1 site score was significantly related to both periphyton and phytoplankton biomass, respectively accounting for 54 and 70% of the total variation in periphyton and phytoplankton data, whereas PC1 only accounted for 18% of the variation in epiphyton biomass. Periphytic and epiphytic biomass were negatively correlated with percent cover and species richness of submergent macrophytes, but phytoplankton biomass was not. We conclude that periphytic and planktonic chlorophyll a biomass are good indicators of human-induced water-quality degradation and recommend that both benthic and planktonic algal biomass should be routinely monitored as part of an effective wetland management program.

scholarly journals Impacts of climate and reclamation on temporal variations in CH<sub>4</sub> emissions from different wetlands in China: from 1950 to 2010

2015 ◽  
Vol 12 (23) ◽  
pp. 6853-6868 ◽  
Author(s):  
T. Li ◽  
W. Zhang ◽  
Q. Zhang ◽  
Y. Lu ◽  
G. Wang ◽  
...  
Keyword(s):  
Climate Warming ◽  
Coastal Wetlands ◽  
Temporal Variations ◽  
Tibet Plateau ◽  
Atmospheric Methane ◽  
Temporal And Spatial Variations ◽  
Ch4 Emissions ◽  
Natural Wetlands ◽  
Temporal And Spatial ◽  
Qinghai Tibet Plateau

Abstract. Natural wetlands are among the most important sources of atmospheric methane and thus important for better understanding the long-term temporal variations in the atmospheric methane concentration. During the last 60 years, wetlands have experienced extensive conversion and impacts from climate warming which might result in complicated temporal and spatial variations in the changes of the wetland methane emissions. In this paper, we present a modeling framework, integrating CH4MODwetland, TOPMODEL, and TEM models, to analyze the temporal and spatial variations in CH4 emissions from natural wetlands (including inland marshes/swamps, coastal wetlands, lakes, and rivers) in China. Our analysis revealed a total increase of 25.5 %, averaging 0.52 g m−2 per decade, in the national CH4 fluxes from 1950 to 2010, which was mainly induced by climate warming. Larger CH4 flux increases occurred in northeastern, northern, and northwestern China, where there have been higher temperature rises. However, decreases in precipitation due to climate warming offset the increment of CH4 fluxes in these regions. The CH4 fluxes from the wetland on the Qinghai–Tibet Plateau exhibited the lowest CH4 increase (0.17 g m−2 per decade). Although climate warming has accelerated CH4 fluxes, the total amount of national CH4 emissions decreased by approximately 2.35 Tg (1.91–2.81 Tg), i.e., from 4.50 Tg in the early 1950s to 2.15 Tg in the late 2000s, due to the wetland loss totalling 17.0 million ha. Of this reduction, 0.26 Tg (0.24–0.28 Tg) was derived from lakes and rivers, 0.16 Tg (0.13–0.20 Tg) from coastal wetlands, and 1.92 Tg (1.54–2.33 Tg) from inland wetlands. Spatially, northeastern China contributed the most to the total reduction, with a loss of 1.68 Tg. The wetland CH4 emissions reduced by more than half in most regions in China except for the Qinghai–Tibet Plateau, where the CH4 decrease was only 23.3 %.

scholarly journals Conversion of Natural Wetland to Farmland in the Tumen River Basin: Human and Environmental Factors

2021 ◽  
Vol 13 (17) ◽  
pp. 3498
Author(s):  
Yuyan Liu ◽  
Ri Jin ◽  
Weihong Zhu
Keyword(s):  
River Basin ◽  
Terrestrial Ecosystem ◽  
Natural Wetland ◽  
Spatial And Temporal Patterns ◽  
Tumen River ◽  
Random Forest Classification ◽  
Forest Classification ◽  
Basin Scale ◽  
Natural Wetlands ◽  
The Relationship

Wetlands play an important role in the terrestrial ecosystem. However, agricultural activities have resulted in a significant decrease in natural wetlands around the world. In the Tumen River Basin (TRB), a border area between China, the Democratic People’s Republic of Korea (DPRK), and Russia, natural wetlands have been reclaimed and converted into farmland, primarily due to the migration practices of Korean-Chinese. To understand the spatial and temporal patterns of this conversion from wetlands to farmland, Landsat remote sensing images from four time periods were analyzed. Almost 30 years of data were extracted using the object-oriented classification method combined with random forest classification. In addition, statistical analysis was conducted on the conversion from natural wetland to farmland and from farmland to wetland, as well as on the relationship between the driving factors. The results revealed that a loss of 49.2% (12,540.1 ha) of natural wetlands in the Chinese portion of the TRB was due to agricultural encroachment for grain production. At the sub-basin scale, the largest area of natural wetland converted into farmland in the past 30 years was in the Hunchun River Basin (HCH), which accounts for 22.0% (2761.2 ha) of the total. Meanwhile, 6571.4 ha of natural wetlands, mainly in the Gaya River Basin (GYH), have been restored from farmland. These changes are closely related to the migration of the agricultural populations.

scholarly journals A Study of Forest Swamp Mapping in Hani Wetland Integrating Sentinel-1 and Sentinel-2 Satellite Images

2021 ◽  
Author(s):  
Jingfa Wang
Keyword(s):  
Information Extraction ◽  
Optimal Number ◽  
Kappa Coefficient ◽  
Artificial Wetlands ◽  
Wetland Type ◽  
Red Edge ◽  
International Importance ◽  
Natural Wetlands ◽  
Landscape Types ◽  
Sentinel 2

As a unique wetland type, forest swamps play an important role in regional carbon cycling and biodiversity conservation. Taking Hani wetland in Jilin province as the research object, we integrated the application of Sentinel-1 radar and Sentinel-2 multispectral images, fully exploited the potential of Sentinel-1 multi-polarization band features and Sentinel-2 red edge index for forest swamp remote sensing identification, and applied the random forest method to realize the extraction of forest swamp distribution information of Hani wetland. The results show that when the optimal number of decision trees for forest swamp information extraction is 1200, the fusion of Sentinel-1VV and VH backscattering coefficient radar band features and Sentinel-2 red-edge band features can significantly improve the extraction accuracy of forest swamp distribution information, and the overall accuracy and Kappa coefficient of forest swamp information extraction in protected areas are as high as 89% and 0.85, respectively. The overall accuracy and Kappa coefficient of forest swamp information extraction in the protected area were 89% and 0.85, respectively. The landscape types of Hani Wetlands of International Importance are diversified, with natural wetlands, artificial wetlands and non-wetland landscape types co-existing. Among the natural wetland types, the forest swamp has the largest area of 27.1 km2, accounting for 11.2% of the total area of the reserve; the river has the smallest area of 0.7 km2, accounting for 0.3% of the total area of the reserve. The forest swamp extraction method provides data support for the sustainable management of Hani wetlands and case guidance for forest swamp mapping in other regions.

Worth of wetlands: revised global monetary values of coastal and inland wetland ecosystem services

2019 ◽  
Vol 70 (8) ◽  
pp. 1189 ◽  
Author(s):  
N. C. Davidson ◽  
A. A. van Dam ◽  
C. M. Finlayson ◽  
R. J. McInnes
Keyword(s):  
Ecosystem Services ◽  
Ecosystem Service ◽  
Coastal Wetlands ◽  
Forested Wetlands ◽  
Wetland Ecosystem ◽  
Natural Wetland ◽  
Wetland Area ◽  
Monetary Value ◽  
New Information ◽  
Wetland Class

In this study, we have re-estimated the 2011 global monetary values of natural wetland ecosystem services using new information on the areas of different coastal and inland wetland classes, and included estimates for forested wetlands. The 2011 global monetary value of natural wetland ecosystem services is now estimated at Int$47.4 trillion per year, 43.5% of the value of all natural biomes. Despite forming only ~15% of global natural wetland area, coastal wetlands are estimated to deliver 43.1% (Int$20.4 trillion per year) of the total global ecosystem services monetary value of all natural wetland classes. There is a need to further refine these value estimates by factoring in other determinants of wetland ecosystem service monetary value, by disaggregating unit monetary values to each wetland class and by updating unit monetary values with more recent sources, especially for ecosystem services with no, or few, value estimates.

Nutrient Transformations in a Natural Wetland Receiving Sewage Effluent and the Implications for Waste Treatment

1994 ◽  
Vol 29 (4) ◽  
pp. 209-217 ◽  
Author(s):  
James G. Cooke
Keyword(s):  
Waste Treatment ◽  
Sediment Traps ◽  
Early Summer ◽  
Sewage Effluent ◽  
Nitrogen Transformations ◽  
Natural Wetland ◽  
Nutrient Processing ◽  
Organic Complexes ◽  
Wetland Treatment ◽  
Natural Wetlands

The processes influencing nutrient (phosphorus and nitrogen) renovation in a natural wetland which had received oxidation pond effluent for twelve years were studied, and compared with current literature perceptions. Mass transport studies showed that 30–70% of the influent P was removed from the water column, which was much greater than published values suggest could be predicted for this highly loaded (∼ 34 g P m−2 y−1) system. Sediment traps studies showed that deposition of particulate P immediately downstream of confluences with arms of the wetland not impacted by sewage effluent (natural wetlands) was the dominant cause of P removal. Separation of the deposited-P into chemically definable fractions along with studies on the water chemistry, suggested that P deposition was associated with iron-organic complexes contributed dominantly from the natural wetlands. Considerable spatial and temporal heterogeneity was also demonstrated for nitrogen transformations. During summer most of the influent-N was in nitrate form which was all transformed during passage through the wetland. Isotope (15N) dilution studies indicated that ∼ 60–70% was denitrified, 25–35% converted to ammonium (dissimilatory reduction), and 5–10% assimilated. For most of the year, however, influent N was mainly in reduced forms. Despite this, significant quantities of nitrate were exported from the wetland especially at higher flows in spring-early summer. Assays on the sediment showed that there was a marked increase in nitrification activity at the confluence with natural wetlands. It is suggested that marked changes in sediment redox potential at these confluence sites provide ideal conditions for nitrification of sorbed ammonium which is subsequently flushed from the system in ‘flood events’. The distribution and type of nutrient processing observed in this wetland are attributable to its configuration. The implication of these results to the sustainability of nutrient renovation in wetland treatment systems is discussed.

Extent, regional distribution and changes in area of different classes of wetland

2018 ◽  
Vol 69 (10) ◽  
pp. 1525 ◽  
Author(s):  
Nick C. Davidson ◽  
C. Max Finlayson
Keyword(s):  
Coastal Wetlands ◽  
Regional Distribution ◽  
Rice Paddy ◽  
Wetland Area ◽  
Inland Wetlands ◽  
Data Gaps ◽  
Natural Wetlands ◽  
Wetland Extent ◽  
Almost All ◽  
Surface Wetland

We compiled available data and information on the global and regional areas (Ramsar regions), and changes in area, of 22 classes of marine or coastal and inland wetlands. From those classes for which there is information, inland natural surface wetlands (forming ~77% of total surface wetland extent) are dominated by non-forested peatlands, marshes and swamps on alluvial soils, with peatlands forming ~33% of natural inland wetlands. The smaller area of marine or coastal wetlands (~10% of total wetland extent) is dominated by unvegetated tidal flats and saltmarshes. Largest areas of human-made wetlands for which there is information are rice paddy and water storage bodies, with a much smaller area of tropical oil palm and pulpwood plantations. These human-made wetlands are all increasing in area. The reported decline in global natural wetland area is occurring across almost all classes of inland and marine or coastal natural wetlands. Total global wetland area estimated from these wetland classes is between 15.2×106 and 16.2×106km2, similar to recent global wetland area estimates derived from remote sensing. Given the considerable data gaps for area of wetland classes, even the most recent other estimates of global wetland extent are likely to be underestimates.

scholarly journals Assessment of Blue Carbon Storage Loss in Coastal Wetlands under Rapid Reclamation

2018 ◽  
Vol 10 (8) ◽  
pp. 2818 ◽  
Author(s):  
Yi Li ◽  
Jianhui Qiu ◽  
Zheng Li ◽  
Yangfan Li
Keyword(s):  
Ecosystem Services ◽  
Carbon Storage ◽  
Coastal Wetlands ◽  
Carbon Emission ◽  
Blue Carbon ◽  
Total Carbon ◽  
Carbon Loss ◽  
Coastal Reclamation ◽  
Natural Wetlands ◽  
Reclamation Area

Highly productive coastal wetlands play an essential role in storing blue carbon as one of their ecosystem services, but they are increasingly jeopardized by intensive reclamation activities to facilitate rapid population growth and urbanization. Coastal reclamation causes the destruction and severe degradation of wetland ecosystems, which may affect their abilities to store blue carbon. To assist with international accords on blue carbon, we evaluated the dynamics of blue carbon storage in coastal wetlands under coastal reclamation in China. By integrating carbon density data collected from field measurement experiments and from the literature, an InVEST model, Carbon Storage and Sequestration was used to estimate carbon storage across the reclamation area between 1990 and 2015. The result is the first map capable of informing about blue carbon storage in coastal reclamation areas on a national scale. We found that more than 380,000 hectares of coastal wetlands were affected by reclamation, which resulted in the release of ca. 20.7 Tg of blue carbon. The carbon loss from natural wetlands to artificial wetlands accounted for 72.5% of total carbon loss, which highlights the major task in managing coastal sustainability. In addition, the top 20% of coastal wetlands in carbon storage loss covered 4.2% of the total reclamation area, which can be applied as critical information for coastal redline planning. We conclude that the release of blue carbon due to the conversion of natural wetlands exceeded the total carbon emission from energy consumption within the reclamation area. Implementing the Redline policy could guide the management of coastal areas resulting in greater resiliency regarding carbon emission and sustained ecosystem services.

scholarly journals Identification of coastal wetlands of international importance for waterbirds: a review of China Coastal Waterbird Surveys 2005–2013

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Qingquan Bai ◽  
◽  
Jianzhong Chen ◽  
Zhihong Chen ◽  
Guotai Dong ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
International Importance

scholarly journals Sustainable Management of Coastal Wetlands in Taiwan: A Review for Invasion, Conservation, and Removal of Mangroves

2019 ◽  
Vol 11 (16) ◽  
pp. 4305 ◽  
Author(s):  
Yu-Chi Chen ◽  
Chun-Han Shih
Keyword(s):  
Sustainable Management ◽  
Coastal Wetlands ◽  
Wetland Management ◽  
Economic Benefits ◽  
Conservation Education ◽  
Western Coast ◽  
Mangrove Forests ◽  
Mangrove Wetlands ◽  
Near Shore ◽  
Rehabilitation Strategy

Mangrove management has been a sustainable concern in coastal wetlands for decades, especially for original near-shore wetlands and environments without mangrove forests. Although studies outlining environmental, social, and economic benefits of mangrove forests have been increasing, few studies have examined sustainability and policies for reducing or removing mangroves. This study explores the current implemented strategies pertaining to the invasion, conservation, and removal of mangroves for wetland sustainability. A total of 19 mangrove sites were sorted out to develop the main patterns and factors for the destruction or protection in estuaries on the western coast of Taiwan. For traditional wetland management, when faced with development pressure, having protected areas under certain laws is a good direction to go for mangrove sustainability. Furthermore, due to the invasion of mangroves in the mudflats, the Siangshan Wetland indicated mangrove removal can be a positive conservation case as an appropriate habitat rehabilitation strategy for benthic organisms. Under special conditions, mangrove removal provides useful insights into the sustainability of wetlands. These insights contribute to facilitating the worldwide move towards sustainable management on mangrove wetlands. The study also presents the following strategies to further reduce or remove mangroves in the coastal wetlands that contain no mangrove forests: (1) Conducting studies to evaluate the effectiveness of mangrove removal; (2) implementing policies to ensure positive influences on coastal wetlands, and (3) providing mangrove conservation education for sustainable development.

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