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Coastal ecosystems provide critical storm and flood protection but are rapidly degrading worldwide, making their restoration urgent. We evaluated whether successional facilitation, where pioneers facilitate climax species, could be leveraged to accelerate coastal dune revegetation. A survey spanning 270 km of Southeast U.S. coastline revealed that Panicum amarum (bitter panicum) supported higher plant richness than Uniola paniculata (sea oats) and that sea oat cover was 230% greater on mature dunes than disturbed dunes, suggesting bitter panicum functions as a pioneer and sea oats as a climax species. A reciprocal transplant experiment confirmed this interpretation: bitter panicum stem production and height fell by 37% and >20 cm, respectively, when planted proximate to sea oats versus in isolation, whereas sea oats produced 38% more and >12 cm taller stems when planted proximate to bitter panicum versus in isolation. A second experiment evaluating the density‐dependence of this facilitative interaction revealed that sea oats transplanted into low densities of bitter panicum grew >15% taller than isolated and high‐density treatments. However, within 7 months, wave inundation eliminated over 60% of propagules in both experiments. To explore foredune inundation frequency and its implications for dune revegetation, we applied empirical wave runup models at 101 locations throughout Volusia County, Florida. While disturbance frequency varied seasonally and annually, sites with low dune crests and steep beach slopes experienced frequent inundation (>50 events/year). Given the interactions between geomorphology and vegetation success, we present a decision matrix to guide managers in determining optimal revegetation methods tailored to project goals and site conditions. [ABSTRACT FROM AUTHOR]

Peatland restoration is essential to preserve biodiversity and carbon stored in peat soils. Common restoration techniques such as rewetting do not always result in the full recovery of peatland taxonomic and functional properties, threatening the resilience of restored peatlands and their carbon stores.Here, we study the use of peat moss inoculation in stimulating the short‐term taxonomic and functional recovery of a wildfire‐impacted peatland using mesocosms at high and low water table depth, representing ideal and adverse hydrological conditions respectively.Inoculation in conjunction with high water tables accelerated the recovery of the vascular plant and prokaryote communities. Importantly, Sphagnum—the keystone genus in these peatlands—only established in inoculated mesocosms. Together, this resulted in an increased CO2 uptake by approximately 17 g m−2 day−1 and reduced overall nutrient content in the peat pore water.Synthesis and applications. Our results indicate that inoculation can be used to accelerate the establishment of peatland‐specific species. In addition, they suggest the potential to combine peat moss inoculation and hydrological restoration to accelerate the uptake of carbon back into the system post‐fire. This offers a basis for future work exploring the long‐term use of inoculation to return disturbed peatlands to their pre‐degraded state, and a wider application of soil inoculation as a mechanism for functional recovery. [ABSTRACT FROM AUTHOR]

Reef‐forming species form integral aspects of coastal ecosystems, but are rapidly degrading world‐wide. To mitigate these declines, nature managers increasingly rely on the restoration of habitat‐structuring, reef‐forming species by, for example, introducing artificial reefs that may directly function as complex reef habitat. Since the use of biodegradable structures to restore biogenic reefs is becoming a popular technique, its effectiveness as reef habitat must be assessed. Therefore, we examine the trophic complexity on experimental large‐scale biodegradable artificial reefs using food web network analysis.We placed biodegradable artificial reefs on soft‐sediment intertidal flats in the Dutch Wadden Sea in a large‐scale (~650 m) and 2.5‐year‐long experiment. We compared food web networks and biodiversity indicators between biodegradable reefs and bare controls and quantified species composition inside and near the artificial reef community to assess the expansion of the reef community.During 2.5 years, we observed that artificial reefs changed food web networks compared to bare controls: in species richness (+76%), link density (the number of interactions per species; +15%) and the fraction of basal species (species of lowest trophic level; +40%), but lowered the connectance: the realized fraction of all possible links between species (−33%). Their effects on food web networks increased over time with a higher species richness (+22%) and more complex food web (link density +13%) on the artificial reef 2.5 years after deployment compared to 1.5 years. However, the effects of the reefs did not extend beyond the reef structures; the species composition and biodiversity of macrozoobenthos near the reefs were comparable to the control.Synthesis and applications. This study shows that biodegradable artificial reefs offer an effective tool for the restoration of food web complexity and biodiversity of intertidal soft‐sediment systems. However, application needs to be carefully considered as the reef‐building species did not expand beyond our structures, despite the ambitious spatial extent of this experiment. Therefore, we recommend restoration practitioners to design artificial reefs in such a way that they generate ecosystem connectivity (facilitation of higher trophic levels) and biogeomorphological effects on a landscape scale (reef expansion beyond the structures). [ABSTRACT FROM AUTHOR]

Many vegetated ecosystems, including drylands, coastal dunes, salt marshes and seagrass meadows, inhabit environments frequently disturbed by the erosive forces of wind and water. Once degraded, the restoration of these systems entails a high risk of failure due to the uncertainty in timing and intensity of future disturbances. Risk‐mitigation strategies like bet‐hedging (i.e. spreading risk over diverse options) have been proven in cross‐disciplinary contexts to optimize yield when uncertainty is high. Yet, restoration designs commonly homogenize resources by planting vegetation of similar sizes in grid‐like patterns. This decision may unwittingly contribute to the high rate of restoration failure in these environments.Using numerical simulations mimicking vegetation patch dynamics, we demonstrate how avoiding uniform planting designs substantially improves the likelihood of restoration success.These simulations also suggest that the intrinsic risk of failure associated with any planting pattern can be identified a priori by calculating the variance‐to‐mean ratio of vegetation cover.Synthesis and applications. By introducing a level of spatial overdispersion (variance in vegetation clustering) into restoration planting designs, projects will insure themselves against the uncertainty imposed by disturbances, limited by their willingness to accept a lower rate of recolonization. [ABSTRACT FROM AUTHOR]

Ecosystems are degrading world‐wide, with severe ecological and economic consequences. Restoration is becoming an important tool to regain ecosystem services and preserve biodiversity. However, in harsh ecosystems dominated by habitat‐modifying organisms, restoration is often expensive and failure prone. Establishment of such habitat modifiers often hinges on self‐facilitation feedbacks generated by traits that emerge when individuals aggregate, causing density‐ or patch size‐dependent establishment thresholds. To overcome these thresholds, adult or juvenile habitat‐forming species are often transplanted in clumped designs, or stress‐mitigating structures are deployed. However, current restoration approaches focus on introducing or facilitating a single life stage, while many habitat modifiers experience multiple bottlenecks throughout their life as they transition through sequential life stages.Here, we define and experimentally test 'life cycle informed restoration', a restoration concept that focuses on overcoming multiple bottlenecks throughout the target species' lifetime. To provide proof of concept, and show its general applicability, we carried out complementary experiments in intertidal soft‐sediment systems in Florida and the Netherlands where oysters and mussels act as reef‐building habitat modifiers. We used biodegradable structures designed to facilitate bivalve reef recovery by both stimulating settlement with hard and fibrous substrates and post‐settlement survival by reducing predation.Our trans‐Atlantic experiments demonstrate that these structures enabled bivalve reef formation by: (a) facilitating larval recruitment via species‐specific settlement substrates, and (b) enhancing post‐settlement survival by lowering predation. In the Netherlands, structures with coir rope most strongly facilitated mussels by providing fibrous settlement substrate, and predation‐lowering spatially complex hard attachment substrate. In Florida, oysters were greatly facilitated by hard substrates, while coir rope proved unbeneficial.Synthesis and applications. Our findings demonstrate that artificial biodegradable reefs can enhance bivalve reef restoration across the Atlantic by mimicking emergent traits that ameliorate multiple bottlenecks over the reef‐forming organism' life cycle. This highlights the potential of our approach as a cost‐effective and practical tool for nature managers to restore systems dominated by habitat modifiers whose natural recovery is hampered by multiple life stage‐dependent bottlenecks. Therefore, investment in understanding how to achieve life cycle informed restoration on larger scales and whether the method it is applicable to restore other ecosystems is now required. [ABSTRACT FROM AUTHOR]

Aim: The formation of a local vegetation mosaic may be attributed to local variation in abiotic environmental conditions. Recent research, however, indicates that self‐facilitating organisms and negative species interactions may be a driving factor. In this study, we explore whether heterogeneous geohydrological conditions or vegetation feedbacks and interactions could be responsible for a vegetation mosaic of rich and poor fen species. Location: Lake Aturtaun, Roundstone Bog, Ireland. Methods: In a floating fen, transects were set out to analyze the relation between vegetation type and rock–peat distance and porewater electrical conductivity. Furthermore, three distinct vegetation types were studied: rich fen, poor fen and patches of poor fen within rich fen vegetation. Biogeochemical measurements were conducted in a vertical profile to distinguish abiotic conditions of distinct vegetation types. Results: Geohydrological conditions may drive the distribution of poor and rich fen species at a larger scale in the floating fen, due to the supply of minerotrophic groundwater. Interestingly, both rich and poor fen vegetation occurred in a mosaic, when electrical conductivity values at 50 cm depth were between 300 µS/cm and 450 µS/cm. Although environmental conditions were homogeneous at 50 cm, they differed markedly between rich and poor fen vegetation at 10 cm depth. Specifically, our measurements indicate that poor fen vegetation lowered porewater alkalinity, bicarbonate concentrations and pH. No effects of rich fen vegetation at 10 cm depth on biogeochemistry was measured. However, rich fen litter had a higher mineralization rate than poor fen litter, which increases the influence of minerotrophic water in rich fen habitat. Conclusions: These results strengthen our hypothesis that species can drive formation of vegetation mosaics under environmentally homogeneous conditions in a floating fen. Positive intraspecific self‐facilitating mechanisms and negative species interactions could be responsible for a stable coexistence of species, even leading to local ecosystem engineering by the species, explaining the local vegetation mosaic at the microscale level in a floating fen. [ABSTRACT FROM AUTHOR]

Background and Aims The growth rate of pioneer species is known to be a critical component determining recruitment success of marsh seedlings on tidal flats. By accelerating growth, recruits can reach a larger size at an earlier date, which reduces the length of the disturbance-free window required for successful establishment. Therefore, the pursuit of natural mechanisms that accelerate growth rates at a local scale may lead to a better understanding of the circumstances under which new establishment occurs, and may suggest new insights with which to perform restoration. This study explores how and why changes in local sediment elevation modify the growth rate of recruiting salt marsh pioneers. Methods A mesocosm experiment was designed in which the annual salt marsh pioneer Salicornia procumbens was grown over a series of raised, flat and lowered sediment surfaces, under a variety of tidal inundation regimes and in vertically draining or un-draining sediment. Additional physical tests quantified the effects of these treatments on sediment water-logging and oxygen dynamics, including the use of a planar optode experiment. Key Results In this study, the elevation of sediment micro-topography by 2 cm was the overwhelming driver of plant growth rates. Seedlings grew on average 25 % faster on raised surfaces, which represented a significant increase when compared to other groups. Changes in growth aligned well with the amplifying effect of raised sediment beds on a tidally episodic oxygenation process wherein sediment pore spaces were refreshed by oxygen-rich water at the onset of high tide. Conclusions Overall, the present study suggests this tidally driven oxygen pump as an explanation for commonly observed natural patterns in salt marsh recruitment near drainage channels and atop raised sediment mounds and reveals a promising way forward to promote the establishment of pioneers in the field. [ABSTRACT FROM AUTHOR]

Globally, aquatic systems face increasing challenges with respect to increased greenhouse gas (GHG) emissions, eutrophication and strongly altered fish community composition. Although it is known that benthivorous fish can influence sediment and water column biogeochemistry, studies showing causal relationships are largely lacking.Here, we used a mesocosm approach with Common carp (Cyprinus carpio) to unravel the effects of bioturbation on GHG and nutrient dynamics. We hypothesised that fish bioturbation decreases methane (CH4) emissions and increases carbon dioxide (CO2) emissions by increased sediment oxygenation. Additionally, lower phosphorus (P) mobilisation was expected due to increased binding to ferric iron (Fe3+).We found that benthivorous fish increased water turbidity, and reduced CH4 diffusion to the atmosphere by 33%, and ebullition by 67%, probably because of sediment oxygenation. Simultaneously, however, CO2 emissions increased due to higher aerobic decomposition, leading to higher overall GHG emissions. In contrast to our hypothesis, we did not find indications of bioturbation affecting P mobilisation from the sediment, probably because P binding was already high in the control treatment as a result of high porewater Fe:P ratios.We conclude that bioturbation by fish has strong effects on GHG emissions as a result of higher overall decomposition rates offsetting reduced CH4 emissions. Depending on porewater Fe:P ratios, benthivorous fish may additionally reduce P mobilisation. [ABSTRACT FROM AUTHOR]

The article highlights that biogeomorphic wetlands serve as the world's biotic carbon hotspots and that conservation and restoration of these hotspots offer an attractive contribution to mitigate global warming. Topics include a key advancement in understanding wetland functioning, human-induced average annual loss rate experienced by worldwide biogeomorphic wetlands, and scientific findings on restoration methods aimed at reestablishing biogeomorphic feedbacks.

The lack of extreme water level fluctuations in managed, non-peat forming wetland ecosystems can result in decreased productivity through the loss of heterogeneity of these ecosystems. Stochastic disruption, such as a water level drawdown, can effectively reverse this effect and return the wetland to a more productive state, associated with higher biodiversity through new vegetation development. Yet, aside from the effect on vegetation dynamics, little is known about longer-term effects (30 years) of a water level drawdown, hereafter referred to as legacy effects, and how this may impact future water level drawdowns. Here, we aim to unravel the legacy effects of a water level drawdown, stand alone and along a water level gradient, on seed bank properties and nutrient availability in a eutrophic clay wetland. To identify these, we studied the hydrologically managed nature reserve Oostvaardersplassen in the Netherlands. Here, one section was subjected to a multi-year water level drawdown and another section was kept inundated. We determined seed bank properties in both areas, spatially and along a soil elevation gradient (20 cm). Nutrient availability was measured by taking sediment samples along the water level gradient and through experimental manipulation of the water level in an indoor mesocosm experiment. Germination was higher in locations with a water level drawdown history, especially at relatively high elevations. Additionally, the proportion of pioneer species in the seed bank was higher in the water level drawdown area. Overall, nutrient concentrations were higher compared to other aquatic systems. Nutrient availability was higher in the inundated area and did not respond to the water level gradient. We conclude that 30 years after an induced water level drawdown there is no depletion of nutrients, while we still observe a legacy effect in the number of viable seeds in the seed bank., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kerstin Bouma reports financial support was provided by Vereniging van Bos- en Natuurterreineigenaren. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Ecosystems shaped by habitat-modifying organisms such as reefs, vegetated coastal systems and peatlands, provide valuable ecosystem services, such as carbon storage and coastal protection. However, they are declining worldwide. Ecosystem restoration is a key tool for mitigating these losses but has proven failure-prone, because ecosystem stability often hinges on self-facilitation generated by emergent traits from habitat modifiers. Emergent traits are not expressed by the single individual, but emerge at the level of an aggregation: a minimum patch-size or density-threshold must be exceeded to generate self-facilitation. Self-facilitation has been successfully harnessed for restoration by clumping transplanted organisms, but requires large amounts of often-limiting and costly donor material. Recent advancements highlight that kickstarting self-facilitation by mimicking emergent traits can similarly increase restoration success. Here, we provide a framework for combining expertise from ecologists, engineers and industrial product designers to transition from trial-and-error to emergent trait design-based, cost-efficient approaches to support large-scale restoration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The agricultural use of drained peatlands leads to huge emissions of greenhouse gases and nutrients. A land-use alternative that allows rewetting of drained peatland while maintaining agricultural production is the cultivation of Sphagnum biomass as a renewable substitute for fossil peat in horticultural growing media (Sphagnum farming). We studied Sphagnum productivity and nutrient dynamics during two years in two Sphagnum farming sites in NW Germany, which were established on drained bog grassland by sod removal, rewetting, and the introduction of Sphagnum fragments in 2011 and 2016, respectively. We found a considerable and homogeneous production of Sphagnum biomass (>3.6 ton DW ha - -1  yr -1 ), attributable to the high nutrient levels, low alkalinity, and even distribution of the irrigation water. The ammonium legacy from former drainage-based agriculture rapidly declined after rewetting, while nutrient mobilization was negligible. CH 4 concentrations in the rewetted soil quickly decreased to very low levels. The Sphagnum biomass sequestered high loads of nutrients (46.0 and 47.4 kg N, 3.9 and 4.9 kg P, and 9.8 and 16.1 kg K ha - 1  yr - 1 in the 7.5 y and 2.5 y old sites, respectively), preventing off-site eutrophication. We conclude that Sphagnum farming as an alternative for drainage-based peatland agriculture may contribute effectively to tackling environmental challenges such as local and regional downstream pollution and global climate change., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Azolla spp., a water fern often used for phytoremediation, is a strong phosphorus (P) accumulator due to its high growth rate and N 2 fixing symbionts (diazotrophs). It is known that plant growth is stimulated by P, but the nature of the interactive response of both symbionts along a P gradient, and related changes in growth-limiting factors, are unclear. We determined growth, and N and P sequestration rates of Azolla filiculoides in N-free water at different P concentrations. The growth response appeared to be biphasic and highest at levels ≥10 P µmol l -1 . Diazotrophic N sequestration increased upon P addition, and rates were three times higher at high P than at low P. At 10 µmol P l -1 , N sequestration rates reached its maximum and A. filiculoides growth became saturated. Due to luxury consumption, P sequestration rates increased until 50 µmol P l -1 . At higher P concentrations (≥50 µmol l -1 ), however, chlorosis occurred that seems to be caused by iron- (Fe-), and not by N-deficiency. We demonstrate that traits of the complete symbiosis in relation to P and Fe availability determine plant performance, stressing the role of nutrient stoichiometry. The results are discussed regarding Azolla's potential use in a bio-based economy.