Degradation, Ecological Restoration and Adaptive Management of Estuarine Wetlands under Intensifying Global Changes

Editors

Tian Xie

Beijing Normal University

Junhong Bai

Beijing Normal University

Milko Alberto Jorquera

University of La Frontera

Laibin Huang

University of California, Davis

Impact

glauca were predicted to participates in the C/N cycle of TCSS (the red bold lines represent the C/N cycle pathway with enhanced enrichment of the rhizosphere bacterial community of S. glauca); The serial number ① indicates the predicted C-cycle model; the serial number ② indicates the predicted N-cycle model; the different capital letters in (A–G) refer to the functional bacteria involved in different stages of the C/N cycle, respectively.

Original Research

09 January 2023

Bacterial community characteristics in the rhizosphere of Suaeda glauca versus bulk soil in coastal silt soil modified by sea-sand and their implications

Xiaochi An

, 5 more and

Bin Lian

1,663 views

1 citations

Original Research

11 November 2022

Differential patterns and assembly processes of bacterial communities from distinct microhabitats in a subtropical estuary

Kang Ma

, 3 more and

Jingling Liu

1,279 views

2 citations

Original Research

08 November 2022

Spatiotemporal coastline variations in the Pearl River Estuary and the relationship with multiple human disturbances

Xin Li

, 3 more and

Huicai Yang

1,454 views

4 citations

[*Correlation is significant at p < 0.05 level (2-tailed); **Correlation is significant at p < 0.01 level (2-tailed)].

Original Research

25 October 2022

Soil organic carbon stabilization and associated mineral protection in typical coastal wetlands under different hydrologic conditions

Haixiao Zhao

, 5 more and

Guanhong Chen

3,114 views

5 citations

(A) Soil hardness after the two treatments. Each group is a combination of the treatments for each of the three types bare patch (N = 54 with 18 controls from three bare patches). (B) Results of seed addition when the two treatments were applied (N = 72 with 32 controls). (C, D) Photographs of emerged S. salsa seedlings after the removal and plowing treatments, respectively. (E, F) Photographs of the caged and blank control treatments showing no emerged seedlings, respectively. BP1, BP2, and BP3 represent complete-enclosed, semi-enclosed, and open bare patches, respectively. Data are means ± SE and significant differences are shown by different letters above the bars.

Original Research

17 October 2022

Artificial modifications lead to the formation of persistent bare patches in saltmarshes

Qing Wang

, 5 more and

Andong Wang

1,383 views

2 citations

Original Research

14 October 2022

Characteristics and influencing factors of metal distribution in different wetlands of the Liaohe Delta, Northeastern China

Yang Yu

, 5 more and

Junbao Yu

2,162 views

2 citations

Original Research

04 October 2022

Crab contributions as an ecosystem engineer to sediment turnover in the Yellow River Delta

Tian Xie

, 4 more and

Dongdong Shao

Data are shown as means ± SE. Lowercase letters indicate significant differences among different water depth datasets and capital letters indicate significant differences among burrow density datasets, with a Tukey test.

Burrowing crabs are widely distributed and have large populations in estuarine wetlands. Crab excavation can have potentially significant bioturbation effects on the vertical structure of sediments, and the processes of nutrients deposition and mineralization. However, the effects of crab micro activities on the geochemical cycling processes of the whole estuarine ecosystems are not clear, specifically the contributions of burrowing crabs to sediment and nutrients turnover in coastal ecosystems. Due to the lack of knowledge on crab burrowing behavior and borrow morphology, it is difficult to accurately estimate the excavation and turnover volumes of crabs. Therefore, this study examined the bioturbation activity of the crab Helice tientsinensis in western Pacific estuary ecosystems by analyzing their burrow morphology and local sediment properties. The common burrow shapes of Helice tientsinensis were J- and Y-shaped burrows. Burrow morphological characteristics such as total burrow depth, curve burrow length, burrow volume, and opening diameter significantly differed among tidal zones. Crab carapace size, water depth, soil hardness, and bulk density were the main factors driving burrow morphology. Sediment excavation by crabs was ~50 times greater than the deposition of sediment into crab burrows. The net transported amounts of sediment (31.66–33.18 g·d^-1·m^-2) and nutrients (total nitrogen: 0.075–0.090 g·d^-1·m^-2, total carbon: 3.96–4.55 g·d^-1·m^-2, and organic matter: 0.44–0.77 g·d^-1·m^-2) were mainly from the belowground sediment to the surface. These results highlighted the important role of crabs in sediment and nutrients cycling within coastal estuary ecosystems.

4,028 views

10 citations

Original Research

29 September 2022

Effects of ecological restoration on soil biogenic elements and their ecological stoichiometry in the Yellow River Delta, China

Dongxue Li

, 7 more and

Chunguang Che

1,798 views

5 citations

Rows a, b, c and d represent different sample areas. Columns indicate 1) sample area locations (red boxes), 2) RSEIs of the sample areas in 2000 and 3) 2020, 4) true-colour composite Landsat 5 image in 2000 and 5) true-colour composite Landsat 8 image in 2020.

Original Research

02 September 2022

Ecological environmental quality assessment of Chinese estuarine wetlands during 2000–2020 based on a remote sensing ecological index

Zhen Zhang

, 2 more and

Xiaohui Guo

7,277 views

12 citations

Original Research

15 September 2022

Food resources for Spoon-billed Sandpipers (Calidris pygmaea) in the mudflats of Leizhou Bay, southern China

Xiuyuan Lu

, 7 more and

Xinpeng Rao

3,553 views

2 citations

Original Research

17 August 2022

Response of soil carbon fractions and enzyme activities to mowing management on in a coastal wetland of the yellow river delta

Qian Cui

, 4 more and

Jingtao Liu

2,039 views

5 citations

Original Research

22 August 2022

Role of DNA methylation in ecophysiological responses to salinity in natural populations of Phragmites australis from coastal and inland habitats

Huijia Song

, 6 more and

Weihua Guo

1,506 views

5 citations

Original Research

06 September 2022

Spatial suitability evaluation of spawning reach revealing the location preference for fish producing drifting eggs

Huabin Zhou

, 3 more and

Xiaoshu Hou

1,939 views

3 citations

Original Research

16 August 2022

Phylogenetic relationship and soil salinity shape intraspecific trait variability of Phragmites australis in the Yellow River Delta

Yiming Wu

, 2 more and

Weihua Guo

Soil salinization has been one of the main causes of ecosystem degradation in many estuarine wetlands under global climate changes, but it remains unclear how salinization shifts the phenotypic variability and genetic diversity of the foundation plant species in estuarine wetlands. To reveal the effects of salinization on natural populations of foundation plant species, we investigated the intraspecific variation of Phragmites australis using five functional traits (shoot height, leaf length, panicle length, seed number per panicle, and mass per seed) and ten microsatellite markers in the five sites across the Yellow River Delta. The salinity was indicated by electrical conductivity, and the reproductive strategy was estimated by the ratio of panicle length to shoot height. The linear models showed that the shoot height, leaf length, and panicle length had significantly negative correlations to soil salinity, while the mass per seed had a significantly positive correlation to soil salinity. However, there were no significant relationships between the seed number per panicle or reproductive ratio and soil salinity. The genetic diversity within populations was high in all sites (He > 0.5), but the genetic differentiation between populations was very weak (F_ST from 0.0074 to 0.0212), which suggested that there was a strong genetic flow among populations. Genetic structure analyses showed two phylogenetic groups of P. australis distributed in four of five surveyed sites across the Yellow River Delta. Our study also found significant phylogenetic signals in the leaf length and mass per seed, suggesting a substantial role of phylogenetic relationship (technically, neutral genetic relatedness) in intraspecific variation and salt adaptation of P. australis. Our study provides novel insight into the adaptative responses of the foundation plant species to soil salinization from individual traits to population genetics and offers significant implications for ecological restoration and adaptive management of saline lands in estuarine wetlands.

2,258 views

8 citations

alterniflora: DEM (A); soil salinity (B); artificial ditch (C); Milu influence range (D).

Original Research

15 July 2022

Examining the expansion of Spartina alterniflora in coastal wetlands using an MCE-CA-Markov model

Dandan Yan

, 4 more and

Zhaoqing Luan

The spread of Spartina alterniflora (smooth cordgrass) has put biodiversity and ecosystem function at risk since it was introduced to China just a few decades ago. A better understanding of how the range of S. alterniflora will expand in the future will help manage the invasion of this species in coastal wetlands. However, it is difficult to model the future extent of Spartina saltmarshes in China. To address this issue, we combined multi criteria evaluation with traditional CA Markov model to provide robust forecasting of the spatial expansion of S. alterniflora for the next ten years, at Dafeng Milu National Nature Reserve, Jiangsu, China. Our results showed that, compared with the interpretation results of high-resolution remote sensing images in 2020, the kappa coefficient of verification accuracy was 82.63%, indicating that the MCE-CA-Markov model has good prediction results. Therefore, the model can forecast the expansion process of S. alterniflora over the next ten years. The model predicts that the area of S. alterniflora continued to decrease from 910.25 ha in 2020 to 881.21 ha in 2030. The spatial distribution of S. alterniflora has been decreasing on the landward side while it has been expanding towards the sea on the seaward side. This study provides some suggestions for effective management and control of invasive species, which could be important for wetland biodiversity conservation and resource management.

1,779 views

14 citations

Abbreviations for the trophic groups: Biv, bivalves; Ca, Carassius auratus; Cra, crabs; Gas, gastropods; Ins, Insects; Lj, Lateolabrax japonicus; OtC, other crustaceans; Ph, Planiliza haematocheila; Pol, polychaetes; Sh, Synechogobius hasta; Shr, shrimp; Zoo, zooplankton. The position of consumers on the x-axis from left to right represents an increase in the mean trophic position of the consumers across the four habitats. Significant differences in the trophic positions of the consumers among the four habitats were evaluated by one-way ANOVA (*p < 0.05; ***p < 0.001). Bars for a given trophic group that are labeled with different letters differ significantly (Tukey’s HSD test, p < 0.05).

Original Research

10 June 2022

Trophic Diversity and Food Web Structure of Vegetated Habitats Along a Coastal Topographic Gradient

Xiaoxiao Li

, 2 more and

Zhifeng Yang

2,558 views

4 citations

Original Research

02 June 2022

Dynamics of Carbon Storage in Saltmarshes Across China’s Eastern Coastal Wetlands From 1987 to 2020

Jingtai Li

, 5 more and

Zhaoqing Luan

Saltmarsh carbon storage contributes significantly to combating global climate change and achieving regional carbon neutrality. Yet saltmarsh carbon stocks have shown a trend of decline in recent years. Therefore, long-term monitoring and analyzing of saltmarshes for their carbon storage is imperative to better protect and manage this pool of carbon. This study investigated the spatiotemporal dynamics in saltmarsh carbon storage during 1987–2020, by using the Google Earth Engine (GEE) platform and applying the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, and analyzed the driving factors of carbon storage in saltmarshes. The key results are as follows. Firstly, carbon density values in saltmarshes ranged more than 14-fold, from 7.24 to 104.99 Mg·hm^-2, and the total carbon storage showed a decreasing trend. Secondly, reduced carbon storage was concentrated in inshore saltmarshes adjacent to reclamation sites, especially in Shandong, whereas augmented carbon storage characterized the offshore saltmarshes dominated by Spartina alterniflora, especially in Shanghai and Jiangsu. Overall, the carbon stocks of saltmarshes have fallen by 10.44 Tg; the decrease in carbon storage caused by Suaeda salsa, Phragmites australis, and mudflats exceeded the increase in carbon storage caused by Spartina alterniflora and Scirpus mariqueter. Further, we found that reclamation was the most dominant driver of carbon storage reductions, except for sea level rise and hurricane disturbances that can also negatively impact carbon storage, while greater carbon storage was closely related to the invasion of Spartina alterniflora. This study’s findings facilitate the development of a carbon storage management strategy for saltmarsh ecosystems to address global climate change and contribute to attaining carbon neutrality.

5,107 views

18 citations