Restoration Projects Research Articles

Assessing the Effectiveness of Large-Scale Ecological Restoration Measures in the Liaohe Estuary Using a Landscape Pattern Perspective

In recent years, the Chinese government implemented many policies and actions to restore coastal wetlands. This study focused on assessing how these projects have influenced the landscape patterns of the Liaohe Estuary, an area of critical importance. By analyzing remote sensing images from 2009 to 2022, we determined the spatiotemporal changes in landscape pattern, fragmentation, and conversion. Results showed that (1) Reed (Phragmites australis) fields were the dominant landscape feature and covered 46.3–48.2% of the area; however, road was the serious factor in fragmenting these wetlands. Seepweed (Suaeda salsa) marshes, an iconic and characteristic wetland of the region, gradually expanded towards the estuary and coast over the study years. (2) Landscape fragmentation increased and seasonally changed during the study period and restoration measures actually resulted in more fragmentation of the landscape. (3) Ponds replaced 14.28 km2 natural landscape in the development stage and 40.93 km2 were restored to natural landscape during restoration and maintenance. (4) Active restoration projects caused landscape fragmentation to sharply increase initially, but then fragmentation declined as passive restoration continued in the maintenance stage. This study suggests that road construction should be carefully deliberated in ecologically sensitive areas and that ecological restoration (a combination of active and passive restoration) in the Liaohe Estuary region showed evidence of temporal lag and hysteresis that may be important for research in the future.

The global cost of international commitments on land restoration

AbstractLand restoration and sustainable land management projects have now been proposed for up to a billion hectares globally, responding to continuous land degradation processes. But, a lack of reliable cost estimates hinders implementation, which results in a high perceived risk of restoration investments. This study addresses this gap, using cost data from 243 restoration projects from multiple sources to estimate the cost ranges for different types of restoration more precisely. The analysis shows median restoration costs vary from 185 $US/ha to 3012 $US/ha depending on the restoration measure, implying current global land restoration commitment cost 0.04%–0.27% of annual global GDP to implement. Since the majority of these commitments are made by developing countries, international cost‐sharing mechanisms, through climate or private finance, are required to move from goal setting to implementation.

Scientific-Practical Enhancement Principles for the Long-Term Stability of Cultural Heritage Objects through a Multi-Component Underground Space Analysis

This article presents approaches for enhancing engineering-geological and geotechnical research for the restoration and reconstruction projects of cultural heritage objects in St. Petersburg’s historical center. According to the Venice Charter, an interdisciplinary approach is recommended for developing a preservation program for cultural heritage objects. The authors consider the underground space as a multi-component system, where soils are a host medium for underground water with specific composition, complex physicochemical and biochemical conditions, the presence and vigorous activity of microorganisms, gases of various origins, and underground bearing and enclosing structures. The last of these components is crucial for the long-term stability of historical and cultural objects, as they interact in complex with water-saturated soils and microorganisms. This approach is not to be found in Russian cultural heritage preservation regulations. In engineering-geological and geotechnical research, multi-component underground space should be studied at the regional, local, and object levels. Assessing redox conditions in the underground environment is crucial for understanding the state of its components. Moreover, this can trigger hazardous processes such as changes in the stress–strain state and unconsolidation of the soil layer due to the generation of low-solubility gases and biocorrosion of ancient and modern building materials, causing premature destruction. Recommendations are provided for carrying out engineering-geological and geotechnical research based on cultural heritage objects, considering the multi-component underground space and features of its geoenvironmental state due to the long-term contamination and transformation of its components.

New Acoustic Design for the Piscina Mirabilis Located nearby the Port of Misenum

Many heritage buildings from ancient Rome are being refurbished based on their original plan’s structure. One of them is the piscina mirabilis located nearby in Naples, which was a cistern used by the Romans to collect drinkable water for the navy waiting in the port of Misenum. The piscina mirabilis has similar architectural characteristics to a “cathedral”; however, its current precarious architectural state is the result of high levels of humidity that have caused the proliferation of mold on its vertical and horizontal surfaces over the centuries. Acoustic measurements were conducted inside the piscina mirabilis, highlighting an existing condition of the room being very reverberant, not suitable for occasional speech and conversations. The design proposed by the authors involves some mitigation solutions for the acoustics, mainly focused on controlling the low–medium frequencies and the realization of a restoration project consisting of a raised timber-floored walkway that runs along the perimeter walls, with the addition of water covering the existing floor as a natural element dominating the room volume, which represents the primary function of the building in antiquity. A waterfall was designed to be on the northern side wall. Acoustic studies were an important part of the refurbishment strategy, and a mitigation solution was devised to control medium–low frequencies by using inflated balloons of different sizes that were suspended from the ceiling vaults instead of widely used acoustic panels. The proposed strategy lowered the reverberation time by 3–4 s to accommodate a minimal level of conversational understanding. Such a solution is appropriate for this heritage building as well as other future conservation projects.

Understanding the seasonal growth patterns of seedlings in forest restoration of post-bauxite mining area: insights for monitoring in the Atlantic Forest

Understanding the behavior of planted seedlings and how they respond to changes in the rainfall regime is a challenge for forest restoration projects. This study aimed to assess the phytosociological structure and compare height and diameter at ground level (DGL) increments between the dry and rainy seasons in a forest restoration area post-bauxite mining in Descoberto-MG, Southeast Brazil. The study area features a dry season (from April to September) and a rainy season (from October to March). Three assessments were conducted for height and DGL increments: at the beginning, end of the dry season, and end of the rainy season. Three plots of 15x15m were established, and all planted individuals were measured over one year. Phytosociological parameters and diversity indices were calculated to select the 10 species with the highest importance value index (IVI). Welch's t-test (p<0.05) was used to compare average increments between seasons. Height and DGL increments during the rainy season were statistically higher than during the dry season for all 10 evaluated species. In height, the greatest increments were observed in Inga vera (590%), Enterolobium contortisiliquum (458.8%), and Piptadenia gonoacantha (343.8%). In DGL, the highest increments were observed in Schinus terebinthifolia (1427.2%), Anadenanthera peregrina (849.2%), and Peltophorum dubium (745.7%). Seasonal monitoring of planted seedlings is essential to understanding growth patterns, especially in Atlantic Forest restoration projects. These findings enable adjustment of management strategies, optimization of maintenance actions, and assistance in selecting species adapted to specific environmental conditions, particularly regarding water availability.

Navigating challenges: leveraging Brisbane Port's success for Kolkata Port's sustainability

ABSTRACT This paper proposes a policy for the sustainable operation of Kolkata Port drawing lessons from Brisbane Port. The paper analyses the operational challenges of Kolkata Port, the successful case of Brisbane Port and formulates policy based on comparison. The analysis suggests upstream restoration projects, river boundary maintenance and modernisation of dredging activities for port operations. Also, it emphasises efficient sediment disposal methods and eco-friendly practices. The policy suggestions in this paper provide a practical roadmap for Kolkata Port Trust and other stakeholders to improve port operations. Implementation of these will lead to better navigation, cost reduction and environmental benefits. This paper contributes original thought by synthesising lessons from the Brisbane Port case study and applying them to Kolkata Port. The policy suggestions are tailored to address the unique challenges of riverine ports like Kolkata.

A systemic analysis of participatory land and water governance in the Tsitsa River Catchment, South Africa

AbstractEffective governance of complex social‐ecological systems requires diverse stakeholders to be engaged in meaningful participatory processes. Meaningful participation must be intelligible and significant to local actors and coherent within a broader, multilevel governance system. This study explores the complexities of participatory land and water governance in South Africa's Tsitsa River Catchment. Embedded within a transdisciplinary landscape restoration project (the Tsitsa Project), this study combines a diagram‐based analysis of local actor mental models with a narrative‐based analysis of participant observation data. Challenges, opportunities, and general principles are identified. Limited accessibility, resource constraints, and the legacy of centralised governance impede participation. The research identifies the critical role of local actors, particularly those with deep community ties, in driving inclusive processes. Building trust through face‐to‐face interactions and culturally appropriate communication strategies also emerged as vital elements for success. This research can inform participatory projects and interventions in rural and developing world contexts.

Dominant role of grazing and snow cover variability on vegetation shifts in the drylands of Kazakhstan

Decomposing the responses of ecosystem structure and function in drylands to changes in human-environmental forcing is a pressing challenge. Though trend detection studies are extensive, these studies often fail to attribute them to potential spatiotemporal drivers. Most attribution studies use a single empirical model or a causal graph that cannot be generalized or extrapolated to larger scales or account for spatial changes and multiple independent processes. Here, we proposed and tested a multi-stage, multi-model framework that detects vegetation trends and attributes them to ten independent social-environmental system (SES) drivers in Kazakhstan (KZ). The time series segmented residual trend analysis showed that 45.71% of KZ experienced vegetation degradation, with land use change as the predominant contributor (22.54%; 0.54 million km2), followed by climate change and climate variability. Pixel-wise fitted Granger Causality and random forest models revealed that sheep & goat density and snow cover had dominant negative and positive impacts on vegetation in degraded areas, respectively. Overall, we attribute vegetation changes to SES driver impacts for 19.81% of KZ (out of 2.39 million km2). The identified vegetation degradation hotspots from this study will help identify locations where restoration projects could have a greater impact and achieve land degradation neutrality in KZ.

Riverbank fascines mostly fail due to scouring: Consistent evidence from field and flume observations

AbstractThe willow fascine soil bioengineering technique is commonly used worldwide in river restoration projects to stabilize riverbanks, thanks to high theoretical shear stress resistance and adaptable configuration. Fascines are composed of bundles of living branches fixed between stakes. When positioned in meanders at bank toe, they are subjected to strong hydraulic constraints. Here, we present the field back‐analysis of 470 willow fascines alongside experiments in a small‐scale model (scale 1:25). We describe the dynamics of failure in various situations. The field analysis revealed that 78% of fascines present no signs of bank instability. No fascines were pulled out, and they rarely showed signs of destruction once vegetation had established. Flume experiments confirmed that the main mechanical process of failure is erosion at fascine toe and extremities (9% and 3% of occurrence in the field, respectively). The dynamics of failure occur through: (i) erosion at the fascine toe, removing materials under the bundle; (ii) bank sediments, sliding underneath the fascine; (iii) scouring, leaving stakes exposed to falling into the river. Based on these observations, the fascine toe should be protected sufficiently deeply against undermining to keep sediments in place while vegetation is established. Bank slopes should be reduced as far as possible to decrease scouring. Finally, the mean shear stress values used as reference when designing bioengineering techniques do not capture the local and continuous scouring processes leading to failure. Thus, bend curvature, degradation, grain sizes, and level of fascine implementation should be considered when adapting design.

Evaluation of acoustic environmental effects and improvement method of ecological fish-nest bricks in the Yangtze River Basin: A model-based case study

With the rapid development of the Yangtze River Basin, the issue of underwater noise pollution has become increasingly severe, which has adversely affected aquatic creatures, particularly fish. Ecological fish-nest bricks (EFNBs), a new type of eco-friendly revetment, can provide a favorable habitat for fish. However, its effects on the acoustic environment remain unclear. The finite element numerical simulation method of acoustic-structure coupling is adopted to explore the acoustic environment of EFNBs, analyzing the impact of sound source frequency (within 300 Hz), structural forms, and arrangement of these bricks on the internal sound pressure level. The sound pressure level distribution of A-EFNBs were also analyzed at a distance of 0–0.5 m from the opening. A method of acoustic environment improvement is proposed, which utilizes porous polyurethane sponge (PPS) sound-absorbing material to establish a conducive acoustic environment for fish in EFNBs. The study results indicate that at low frequencies of sound source (f ≤ 150 Hz), the sound pressure level within EFNBs slightly decreases compared to the adjacent areas without EFNBs. The sound pressure level variation within the bricks increases with sound source frequency. The peak sound pressure increases with the number of openings. Interval arrangements can in general decrease sound pressure by less than 20 dB. At higher frequencies(f＞200 Hz), the sound pressure level at the opening of the A-EFNBs tends to increase. However, the PPS sound-absorbing material substantially reduces the sound pressure level by 15 –55 dB, rendering it an effective method for improving the acoustic environment for fish. The PPS sound-absorbing material is more suitable for habitat improvement of black carp (Mylopharyngodon piceus) and grass carp (Ctenopharyngodon idellus) with relatively low hearing thresholds among the four famous Chinese carps. The research findings can serve as a reference for designing and implementing river ecological restoration projects.

Leveraging atmospheric moisture recycling in Saudi Arabia and neighboring countries for irrigation and afforestation planning

Effective irrigation planning is crucial for sustainable agricultural development and ecosystem restoration projects in arid regions. With respect to ambitious greening initiatives, Saudi Arabia is establishing a national strategy toward a more sustainable and eco-friendly future not only for itself but also for the broader Middle East region. Thus, comprehensively understanding the water cycle in the region is essential to identify the most suitable target locations for afforestation and reforestation while considering the potential role of irrigation. Herein, in addition to traditional pedoclimatic factors, we introduce a complementary consideration—“irrigation recycling.” Building on the well-established concept of atmospheric moisture recycling and taking advantage from an atmospheric trajectory dataset, we track the path of evaporated water from current or potential irrigated sites to the location where the evaporated water eventually falls as precipitation. Our analysis offers two key benefits. First, it helps pinpoint the regions in which and the periods during which water recycling is maximum within the country, aiding more precise calculations of the investment return value for irrigation infrastructures. Second, it helps identify the land-use change patterns that contribute to international efforts such as drought mitigation in East Africa as an example. We found that one-third of the actual precipitation in the current Saudi irrigated sites originated from evapotranspiration over land, mainly from Saudi Arabia and surrounding countries. Interestingly, most of the evapotranspiration from these irrigated sites will eventually fall somewhere over land (primarily in Iran). Controlling the seasonality and spatial distribution of the future irrigation expansion will allow controlling the atmospheric moisture recirculation in Saudi Arabia and nearby drought-prone regions such as Eastern Africa. The outcomes of this study will be the subject of future integrated assessments to account for the climatic feedbacks of the land-use change scenarios. At present, they provide crucial insights to support the decision-making process surrounding the Saudi and Middle East Green Initiatives. Further, the presented methodology offers a pragmatic framework that can be applied to similar greening projects for other regions, making it a viable and valuable approach for global sustainability programs.

Spatial patterns of seed removal by harvester ants in a seed tray experiment.

Using a selection of native grass and forb seeds commonly seeded in local restoration projects, we conducted a field experiment to evaluate the effects of seed species, distance of seed patches from nests, and distance between patches on patterns of seed removal by Owyhee harvester ants, Pogonomyrmex salinus (Olsen) (Hymenoptera: Formicidae). To provide context for ants' seed preferences, we evaluated differences in handling time among seed species. In addition, we assessed the influences of cheatgrass, Bromus tectorum (L.) (Poales: Poaceae), and Sandberg bluegrass, Poa secunda (J. Presl) (Poales: Poaceae), cover on seed removal. We found significant differences in removal rates among seed species. In general, seeds placed closer to nests were more vulnerable to predation than those placed farther away, and seeds in closely spaced patches were more vulnerable than seeds in widely spaced patches. However, the strength of these effects differed by seed species. Differences in handling time among seed species may help to explain these findings; the protective effect of from-nest distance was weaker for species that required less time to transport. For 2 of the seed species, there was an interaction between the distance of seed patches from nests and the distance between patches such that the protective effect of distance between patches decreased as the distance from nests increased. Cheatgrass and bluegrass cover both had small protective effects on seeds. Taken together, these results offer insight into the spatial ecology of harvester ant foraging and may provide context for the successful implementation of restoration efforts where harvester ants are present.

Disembedding and Disentangling Grassland Valuation: Insights into Grassland Management Institutions and Ecological Research in China

After two decades of implementing top-down grassland restoration projects focused on reducing livestock numbers and pastoralist populations, the Chinese government’s well-funded efforts have not significantly reversed grassland degradation. This study reviews the institutional changes in grassland management over the past forty years, highlighting the Livestock and Grassland Double Contract Household Responsibility System of the early 1980s and the Grassland Ecological Reward and Compensation Policy introduced in 2011. It demonstrates how these institutional transformations have shaped pastoralists’ evolving understanding of grassland value and reveals that commodifying grassland’s economic and ecological value has led to the capitalization of nature, disembedding husbandry from grassland production, and undermining the effectiveness of conservation projects. This article also showcases the development of grassland ecology research in China, noting its increasing detachment from a holistic understanding of ecosystems and the interdisciplinary needs of management practices. The disjunction between grassland ecology research and practical management has resulted in a lack of techniques aligned with local ecological and socioeconomic contexts. This article champions active engagement with and protection of pastoralist communities to reintegrate grasslands’ true economic and ecological value into management practices, thereby effectively restoring degraded grasslands and achieving sustainable management.

Native bee habitat restoration: key ecological considerations from recent North American literature

Habitat loss is a primary driver of global biodiversity decline, negatively impacting many species, including native bees. One approach to counteract the consequences of habitat loss is through restoration, which includes the transformation of degraded or damaged habitats to increase biodiversity. In this review, we survey bee habitat restoration literature over the last 14 years to provide insights into how best to promote bee diversity and abundance through the restoration of natural landscapes in North America. We highlight relevant questions and concepts to consider throughout the various stages of habitat restoration projects, categorizing them into pre-, during-, and post-restoration stages. We emphasize the importance of planning species- and site-specific strategies to support bees, including providing floral and non-floral resources and increasing nest site availability. Lastly, we underscore the significance of conducting evaluations and long-term monitoring following restoration efforts. By identifying effective restoration methods, success indicators, and areas for future research, our review presents a comprehensive framework that can guide land managers during this urgent time for bee habitat restoration.

Ten golden rules for restoration to secure resilient and just seagrass social‐ecological systems

Societal Impact StatementSeagrass meadows are a globally important habitat subject to significant loss. As efforts to restore these sensitive habitats are hampered by their high cost and low levels of reliability, rigorous guidance is required to improve effectiveness and ensure they are cost‐effective. Here, we define 10 golden rules for how we can undertake seagrass restoration. We do this by considering that for seagrass restoration to be successful, it needs to take place with people and not against people. The framework we present aims to direct efforts for seagrass restoration that are holistic and achieve broad goals for people, biodiversity and the planet.SummaryThe world has lost a significant proportion of its seagrass, and although glimmers of hope for its recovery exist, losses and degradations continue. First and foremost, evidence highlights the need to put the world on a global pathway to seagrass net gain. Achieving this outcome requires that conservation of what remains is a priority, but reaching net gain requires seagrass coverage to increase at rates unlikely to be achieved naturally; large‐scale active restoration is required to fill this gap. Novel finance mechanisms aligned to the climate emergency and biodiversity crises are increasingly leading to larger scale restoration projects. However, no clear framework exists for developing or prioritising approaches. With seagrass restoration expensive and unreliable, rigorous guidance is required to improve effectiveness and ensure it is cost‐effective. Building on evidence from terrestrial and marine sources, here, we apply the ‘10 golden rules’ concept, first outlined for reforestation and later applied to coral reefs, to seagrass restoration. In doing so, we follow international standards for ecological restoration and view seagrass restoration in a broad context, whereby regeneration can be achieved either by planting or by enhancing and facilitating natural recovery. These rules somewhat differ from those on reforestation and coral reef restoration, principally due to the relative immaturity of seagrass restoration science. These 10 golden rules for seagrass restoration are placed within a coupled social‐ecological systems context, and we present a framework for conservation more broadly, to achieve multiple goals pertaining to people, biodiversity and the planet.

Linear relationships between aboveground biomass and plant species diversity during the initial stage of degraded grassland restoration projects.

The relationship between aboveground biomass and plant diversity has been extensively examined to understand the role of biodiversity in ecosystem functions and services. Degraded grassland restoration projects can enhance carbon sequestration. However, the relationship between biomass and diversity remains one of the most actively debated topics regarding grassland ecosystems in degraded grassland restoration projects. We speculated that establishing the linear relationships between aboveground biomass and plant species diversity could contribute to enhancing the efficacy of degraded grassland restoration projects. This study sought to determine whether these relationships were linear during the initial stages of the restoration projects of degraded grasslands in Xing'an League, China. The investigations were based on an examination of seventy-six 1 × 1 m2 plots distributed among 15 areas in which the degraded grassland was at the initial stages of restoration. To quantify the species diversity of the degraded grassland communities, we used the species richness, Shannon-Wiener, inverse Simpson's reciprocal, and Pielou's evenness indices. Our analyses revealed that aboveground biomass had clear positive linear relationships with species richness during the initial stages of degraded grassland restoration. However, there were less pronounced associations with species diversity as assessed using the Shannon and inverse Simpson indices, based on regression models. Furthermore, weed biomass was found to have significant negative effects on species richness and Pielou's evenness. The weak linear relationship between aboveground biomass and species richness could be ascribed to an increase in weed biomass. We concluded that aboveground biomass and plant species diversity could be enhanced during the initial stages of degraded grassland restoration projects and suggest that the extent of weed biomass could serve as a key indicator of the efficacy of restoration from the perspective of plant species diversity and aboveground biomass in carbon sequestration projects.

Environment and Socio-Economic Impact of Mangroves at Mobil, Dunggoan, Danao City, Cebu, Philippines

This study explored the environmental and socio-economic impacts of the mangrove rehabilitation project in Mobil, Dunggoan, Danao City, Cebu. It examined the demographic profile of residents, their perceptions and contributions to the project, and the effectiveness of project monitoring. In addition, the researchers conducted an actual measurement of the height and spread branches of the planted mangroves. The research employed descriptive method, utilizing surveys and direct measurements to assess the survival rate and growth of mangroves, as well as the distribution of marine life using quadrat method. Findings indicate a significant survival rate of mangroves, with Rhizophora stylosa and Rhizophora apiculata being the predominant species. The project has notably enhanced shoreline protection, erosion prevention, aquatic habitat, water quality, and the aesthetic appeal of the cove. The study underscored the necessity of implementing stricter monitoring, waste management, restoration projects, and community awareness programs to improve mangrove rehabilitation.

Characteristics and influencing factors of carbon source/sink variations in the Zoige grassland wetland ecological function zone on the eastern slope of the Tibetan Plateau

Net ecosystem productivity (NEP) refers to the portion of net primary productivity (NPP) that is available for carbon cycling in terrestrial ecosystems after subtracting photosynthetic carbon consumed by heterotrophic respiration. The amount of the NEP reflects the size of carbon sinks/sources in terrestrial ecosystems, holding great significance for the research of climate change and global carbon cycle. In this study, the NEP of the Zoige grassland wetland ecological function zone (ZGW) on the eastern slope of the Tibetan Plateau from 2001 to 2020 is estimated by using the improved Carnegie-Ames-Stanford Approach model for NPP and a statistical model for soil heterotrophic respiration, based on the meteorological data, vegetation data and socioeconomic data. Additionally, the spatio-temporal variations of the NEP are analyzed, and the influences of natural factors and anthropogenic activities on the NEP are investigated. The results indicate that the ZGW overall plays a role as a carbon sink, and the carbon sink area accounts for approximately 99.3% of the whole ZGW. The annual average NEP in the study area is 447.9 g·m−2, showing a gradual increase at a rate of 5.0 g·m−2·a−1, although the increasing trend is not significant. The carbon sink capacity increased in 93.5% of the ZGW, remained relatively stable in 5.9% of the ZGW, and decreased and significantly decreased in 0.6% of the ZGW. Climate warming and humidifying promote the enhancement of carbon sink capacity in the ecosystem of the ZGW, and precipitation is the dominant climatic factor influencing NEP variations. Natural factors are the determinants of NEP variations, while anthropogenic activities play a secondary role. The implementation of ecological restoration and management projects in the areas along the Yellow River, around the main roads and the core area of wetlands, as well as the continuation of green and coordinated development policies of orderly developing grassland resources, is conducive to enhancing vegetation carbon sink capacity of the ZGW.

Development and application of a simplified biophysical model to study deltaic and coastal ecosystems

Many coastal regions around the globe experience land loss due to high relative sea level rise rates, declining sediment supply, and a host of other anthropogenic factors. To evaluate possible restoration strategies, we developed a computationally efficient Simplified Biophysical Model (SBM). The SBM includes hydrodynamic, morphodynamic, and marsh inundation components. The hydrodynamic and mineral sediment processes of the SBM are based on open source Delft3D models. The marsh inundation MATLAB module is a simplified vegetation response to salinity and inundation used to estimate annual organic accretion rates. Organic accretion is added annually to the morphodynamic calculations of mineral sediment. The typical run time for the SBM for an area of 4500 km2 is ∼0.8, 2.5, and 4.7 days real time for one, three, and five decade simulations, respectively which is considered a computationally efficient for modeling decadal landscape evolution. The utility of the SBM was demonstrated through an application to assess the performance of a sediment diversion in the Barataria Basin in Louisiana, USA. The model results demonstrate the importance of incorporating the impact of salinity and inundation effects on the resilience of marshes subjected to high rates of relative sea level rise. Further, the sediment reduction analysis confirms the critical impact of the Mississippi River sediment decline on potential land building from sediment diversions where 1.5%, and 3% annual declining rates show a reduction in net land gain due to Mid-Barataria Sediment Diversion operation of 30% and 50 %, respectively. This highlights the importance of considering the Mississippi River sediment supply decline in restoration projects’ planning and specifically, sediment diversions.

Comparison of the coexistence pattern of mangrove macrobenthos between natural and artificial reforestation.

The abandoned pond-to-mangrove restoration project provides greater advantages than tidal flats afforestation in restoring mangrove ecosystem services and will be the primary method for mangrove restoration in the future. The existing methods for abandoned pond-to-mangrove restoration include artificial restoration through 'dike-breaking, filling with imported soil and tree planting' and natural restoration through 'dike-breaking and natural succession'. However, little is known about which restoration strategy (natural or artificial restoration) provides more benefits to the biodiversity of mangrove macrobethos. Given a prevailing view suggested that artificial restoration should be the preferred approach for accelerating recovery of biodiversity and vegetation structure in tropical regions, we hypothesised higher macrobenthic biodiversity and more complex community structure in artificial restoration than in natural restoration. To test this hypothesis, macrobenthic biodiversity and ecological processes were monitored in a typical abandoned pond-to-mangrove area of Dongzhaigang Bay, China, where artificial and natural restoration methods were used concurrently. Differences in macrobenthic biodiversity, community structure and ecological processes were compared using diversity indices, complex network analysis and null models. Similar species composition and ecological niche overlap and width among macrobenthos were observed at artificial and natural restoration sites. The biotic heterogeneity and interaction among macrobenthos were higher at the natural restoration sites than at the artificial restoration sites. Macrobenthos community assembly at natural and artificial restoration sites was both determined by deterministic processes, with environmental filtering dominating, which explained 52% and 54% of the variations in macrobenthic community structures respectively. Although our findings did not validate the research hypothesis, higher biotic heterogeneity and species interaction among macrobenthos could support natural restoration as the primary method for abandoned pond-to-mangrove projects, because it is a nature-based solution for mangrove restoration.