Resource Database

E9. Presentation of SERIAC, the new Iberoamerican and Caribbean chapter of the SER

E12. Struggling for climate neutrality in Europe: carbon sequestration as an opportunity for large scale restoration of agricultural soils

E1. Commonland. Landscape Restoration as a means of delivering the EU Green Deal: Recommendations

E5. Land Life: examples and challenges in nature restoration through Voluntary Carbon Markets

E7. CEMBUREAU’s vision for biodiversity in and around quarries over the coming decades

E6. Ecoembes. “Los Sistemas Colectivos de Responsabilidad Ampliada del Productor (SCRAP) y las experiencias de restauración ecológica”

S2.1 Forest regrowth after land abandonment in Europe: extent, threats, and opportunities.

S2.2 Forest regrowth after land abandonment in Europe: extent, threats, and opportunities

S10. Restoring Agricultural Land and Other Heavily Transformed Landscapes.

S17. Forest Restoration

S4. Restoration in the Mediterranean Sea: are we ready for scaling up?

Community dynamics during salt marsh restoration over 10 years in a megatidal, ice-influenced environment

Salt marshes are vital ecosystems that provide coastal protection, carbon sequestration, and habitat for many species. Global salt marsh loss has been extensive; in the Bay of Fundy, Canada, an estimated 30,500 ha of salt marsh has been lost since European colonization. There is growing interest in salt marsh restoration to access valuable ecosystem services in an era of climate change and sea level rise. We monitored two managed realignment salt marsh restoration sites and two established salt marsh reference sites for sediment deposition and community dynamics from one year pre-breach to ten years post-breach to better understand successional trajectories in the upper Bay of Fundy. This study was the first of its kind in Maritime Canada and the first managed realignment in an ice-influenced and megatidal (tidal amplitude ~14 m) region. To date, we have identified four successional stages of salt marsh restoration: (1) deposition of unconsolidated sediment (>50 cm in some locations) and loss of terrestrial vegetation, (2) colonization and spread of Spartina alterniflora and loss of surviving S. pectinata (brackish vegetation), (3) homogenization of S. alterniflora cover, and (4) colonization and spread of high marsh vegetation in restoration sites. We expect the invertebrate community on the emergent marsh and in salt pools in the restoration sites to become more like the reference salt marsh community as plant zonation becomes more distinct. Successes and lessons
learned from our project are guiding additional restoration projects in the Bay of Fundy, a region with high potential for salt marsh restoration.

Do predators have a role to play in wetland restoration? An experimental study in New England coastal salt marshes

Traditional approaches to wetland restoration often emphasize reestablishing native vegetation and engineering the correct hydrology along with other environmental features, thereby setting the stage for nature to do the rest. With this bottom-up focus, the biotic diversity of wetlands and their related trophic interactions are treated as measures of restoration success rather than factors that may influence it. However, recent studies have shown that the loss of predators in coastal salt marshes can lead to significant reduction of wetland extent due to overgrazing by herbivores. Such studies indicate that consumers may play a much larger role in the maintenance of wetland ecosystems than was previously thought. Therefore, the objective of this study was to evaluate whether altering top-down control by manipulating the presence of predators can lead to measurable changes in salt marsh ecosystem properties. Between May and August of 2015 and 2016, we established exclosure and enclosure cages within three coastal wetlands and manipulated the presence of green crab predators to assess how consumers affect changes in ecosystem functions. Predator presence was associated with changes in aboveground biomass and the rate of soil nitrogen absorption at one study site, while changes in other ecosystem processes were largely driven by bottom-up factors. These results challenge the recent consensus that consumers have strong effects, instead indicating that predator effects may instead be context-dependent and therefore may not be required for improved restoration outcomes.

Monitoring and Assessment of Valued Ecosystem Components (VEC) in a Constructed Juncus-dominated Salt Marsh on the Northern Gulf of Mexico

Monotypic stands of Juncus roemerianus dominate the marshes of the northeastern Gulf of Mexico, but few studies to date have examined the effects of restoration efforts on faunal inhabitants of these marsh ecosystems. This study examined environmental characteristics, faunal community structure, and trophic support in two restored marshes (5+ yrs and 15+ yrs) and a natural reference marsh (100+ yrs). Microbial diversity assessment in fall 2016 discovered that plants from the restored and reference areas supported similar microbial diversity indicating the rapid colonization of planted grasses with indigenous soil microbiota. Sampling in Spring and Fall 2017 through 2019 assessed the vascular plant community diversity and biomass, as well as relating these parameters to geomorphological characteristics of the area by measuring elevation and soil condition. The two constructed sites were found to have a diverse array of vegetation, but function of the salt marsh in terms of root production and sediment organic carbon deposition remained underdeveloped when compared to the natural reference site. Sampling targeted invertebrate abundances along the transects, which found to be were significantly higher in the natural marsh. Nekton abundance, species richness, and Simpson’s index of diversity varied by site and season. Stable isotope analysis provided additional insight into carbon sources and how energy is transferred through consumers in the restored marshes compared to the natural marsh. To survey breeding marsh birds, we utilized a standardized avian point count methodology to determine occupancy rates and species abundance for restored and natural tidal marsh sites. Construction of the sites with a fully enclosed berm and higher elevation than the natural reference marsh appears to have long-lasting consequences on restoration succession in a number of ecosystem structural and functional metrics.

Pilot salt marsh restoration techniques in New York City, USA: managing ecosystem recovery in an ultra-urban coastal context

Salt marshes are some of New York City’s (NYC) most valuable ecosystems. They are threatened by erosion and rising sea levels. NYC Department of Parks & Recreation (NYC Parks) is piloting innovative techniques to restore these critical ecosystems. NYC, in the northeastern United States (US), has over 8,000,000 human residents, 8,000 hectares of natural areas, and thousands of species of native plants and wildlife. Today, less than 10% of the historic extent of NYC’s salt marsh remains—about 1,600 hectares. To combat this loss, NYC Parks is piloting restoration of eroding coastal wetlands and planning for salt marsh migration. At Alley Creek, Queens, we piloted clean sand placement in the marsh interior and are designing a living shoreline. We will also conduct thin-layer sediment placement at Idlewild, Queens and Four Sparrow, Brooklyn, to increase marsh surface elevation and restore habitat for nesting birds. Finally, we have mapped areas that are likely to be flooded under sea level rise and identified locations throughout NYC to protect and create pathways for marsh migration. With funding from the US Environmental Protection Agency, we will develop monitoring protocols to evaluate the efficacy of these pilot projects and assess the conditions of migration zones. Using SER’s International Standards for the Practice of Ecological Restoration, we will establish target attributes for ecological restoration and conduct annual monitoring to assess their recovery. Successes and lessons learned from these projects have broad application to practitioners conducting salt marsh restoration in ultra-urban coastal areas.

Plant-Soil Carbon Responses to a Thin Layer Placement Experiment in a Southern New England Salt Marsh (USA)

Thin Layer Placement (TLP) of sediment is an increasingly used restoration method in coastal marshes to stimulate plant productivity, subsequently promoting soil accretion and resilience to accelerated sea level rise. However, few experimental field studies have investigated using dredge material for TLP in meso-tidal estuaries, and none holistically examine plant-soil carbon dynamics. Our goal was to investigate the biological and biogeochemical responses of applying dredge material for restoration of a coastal salt marsh in Connecticut, USA. Our objectives were to determine how application of varying levels of sediment affect: (1) above and belowground biomass allocation of Spartina alterniflora, and (2) soil carbon cycling processes including decomposition and carbon mineralization. We used an in situ experiment to manipulate soil surface elevation (low: +5cm, medium: +10cm, and high: +15cm). We monitored plant traits (above and belowground biomass, stem height, stem density, leaf area) and soil parameters (EC, pH, redox, NH4 +, sulfides, C:N, carbon mineralization, decomposition, bulk density). Preliminary analyses suggest low and medium treatments increased stem heights, but reduced stem density compared to controls. No stems grew in the high treatment but had similar root biomass in the medium treatments. These results demonstrate the ability of roots to penetrate the thickest sediment and may lead to increased belowground contributions and marsh resilience. Results from ongoing soil carbon analyses will elucidate relationships between sediment application, plant growth, and carbon cycling dynamics. Collectively, our work will guide wetland managers develop restoration specifications for protecting coastal marshes in the face of rising seas.

Planting the marsh: Comparing methods of planting at recovering salt marsh restoration sites in the Bay of Fundy

Salt marshes provide many important ecosystem services, including coastal protection, and interest in restoring these systems is growing in the face of climate change. In Atlantic Canada, salt marsh restoration has focused on restoring tidal flow, without planting vegetation. Over time, these sites can show persistent deficits in vegetation diversity. We evaluated five methods of planting (plugs, field transplants, seed, wrack, tilling) eight native species (Carex paleacea, Juncus gerardii, Limonium carolinianum, Plantago maritima, Poa palustris, Solidago sempervirens, Sporobolus alterniflorus and Sporobolus michauxianus) at two Bay of Fundy salt marsh restoration sites to test their ability to accelerate plant recovery. Community structure and planting performance (growth rate, summer and winter survival, health) were monitored over two years. Planting plugs produced the highest abundance of perennial halophytes over both years and plantings had high survival rates (76.4 % ± 0.02 SE) while plants transplanted from adjacent sites had higher mortality and slightly lower abundance. All planted
species survived and grew. Growth rate, health, and winter survival were all more strongly related to site than planting treatment, indicating that location was more important than planting method. We found evidence that differences in elevation, inundation, soil salinity and soil nutrients at each site may explain these differences in performance. Planting plugs and field transplants may both be useful for restoration in the future and mixing methods to capitalize on respective strengths may produce best results when planting. Our results also highlight the need to tailor planting plans to individual sites as plantings may respond differently in different situations.

Applying an animal-centric approach to restoration for wildlife

Habitat loss and fragmentation are leading causes of biodiversity decline. To restore landscapes that support native animals requires moving beyond the traditional focus on vegetation to grounding restoration activities in mechanistic knowledge of the local and landscape elements that different species require. We developed an animal-centric approach to ecological restoration and applied this to native mammals and birds in the Tasmanian Midlands, Australia’s oldest and most fragmented European agricultural region. Greening Australia is planting biodiversity corridors, connecting and restoring woodland across the region. We used species-appropriate technologies to assess the decisions made by individual animals to find food and shelter and to disperse across this fragmented landscape, and linked these, together with patterns of occupancy, across multiple spatial and temporal scales. We focussed on a native (Spotted-tailed Quoll Dasyurus maculatus) and an invasive (Feral Cat Felis catus) carnivore, a woodland-specialist herbivore (Eastern Bettong Bettongia gaimardi), microbats and woodland birds including the native-invasive Noisy Miner. Our results, which show intense predatory and competitive pressure of Feral Cats and Noisy Miners on native fauna, demonstrate the significance of structural complexity of restored vegetation for supporting the recolonisation and persistence of native fauna and evoke innovative approaches in plantings and artificial refuges to reduce habitat suitability for Noisy Miners and predatory impacts of Feral Cats. At large landscape-scale, we demonstrate the importance of retaining small habitat elements, including ancient paddock trees, pivot irrigation corners and small, degraded remnants, in facilitating occupancy and dispersal and therefore persistence of wild animals across this agricultural region.

Community bird changes due to ecological restoration of terrestrial areas on an Andean periurban wetland (Bogotá, Colombia)

The native ecosystems of the Bogotá plateau have been transformed as a consequence of the dynamics of occupation, finding today remnants of wetlands with bird species in a serious threat of extinction. In response to those changes, ecological restoration research line of Bogotá Botanical Garden establishes the Pilot Area of Research on La Florida Regional Park. An area of high importance for bird conservation, and an opportunity to propose birds as indicator of the restoration success. The park has six land covers, including two covers with around ten years of restoration process, two without restoration (a mixed forest plantation and a recreational zone), one of a natural wetland habitat and a lake. The areas in restoration process was established using implantation designs with native plants. The success of the vegetation process was measured using the variables as: survival, composition and structure that could explain changes on bird communities produced by the restoration, serving as a comparative framework. In total, 170 species were recorded throughout the park, including species of conservation importance. The greatest changes are observed in the covers under restoration in which there is a significant increase on bird diversity that can be explained by structural variables of vegetation such as growth habits, strata and in general understory features. Similarly, changes were found in the cover without restoration, in which has a similar structure to the coverage under restoration, but with less diversity of plant and bird species. Those results highlight the importance of bird monitoring in ecological restoration processes, and also highlighting compositional and structural variables that can boost an increase in bird diversity.

Evaluation of ecological restoration through mammal monitoring in a lava field of Mexico City

The Pedregal de San Ángel Ecological Reserve (REPSA) has been affected by substrate destruction, introduction of invasive plant species, the presence of domestic rodents and feral fauna. Several patches have been subjected to rescue of basaltic substrate and mechanical subtraction of exotic plants, like Eucalyptus spp. To evaluate the degree of recovery, we compare mammalian communities associated to sites subjected to 11-13 years of ecological restoration and conserved areas. Sherman traps were placed during the dry and rainy seasons. Density of cottontail rabbits was determined through the density of their fecal pellets; other mammals were registered through excreta and sightings. In the sites under restoration, six species of native mammals were recorded: Peromyscus gratus, P. melanophrys, Otospermophilus variegatus, Didelphis virginiana, Bassariscus astutus and Sylvilagus floridanus; and three exotic mammals: gray squirrels, cats and dogs. All sites were shelter for native mammals. Peromyscus gratus was recorded in all sites, and they depend on the lava-field ecosystem but, as a generalist mouse, it is a useful indicator at the first stages of restoration. Exotic rodents were no longer found in the sites subjected to restoration, and their absence could be a good restoration progress indicator because their populations have decreased without direct control. It was found that the basaltic substrate addition strategy to improve plant community might affect the P. gratus and S. floridanus activity. Considering mammals since planning is important, because focusing on the plant community strategies might not generate a suitable habitat for mammals.

Removal of an invasive wetland grass (Phragmites australis) increases the quantity of emerging invertebrates and avian aerial foraging activity

Invasive Phragmites australis subsp. australis (European Common Reed) is now found throughout North America. Phragmites australis displaces resident vegetation and replaces it with tall, dense stands that negatively alter wetlands. To contend with invasion, the Ontario government began a project to control P. australis and restore native vegetation diversity in Long Point, ON, a peninsula located on the north shore of Lake Erie, by aerially applying glyphosate-based herbicide. Since Long Point is ecologically significant and a regional biodiversity hotspot, we wanted to assess how restoration influenced its ecological function and habitat value for species at risk. In particular, we quantified the amount and quality of emerging invertebrates (secondary production) and the foraging activity of aerial insectivore birds (i.e. swallows), including Barn Swallows (Hirundo rustica), which are classified as threatened in Ontario. We paired point-count surveys with emergence traps in 2017 and 2018 in herbicide-treated marsh habitat, invaded (P. australis) habitat, and resident (i.e. meadow marsh, cattail marsh) habitat. Preliminary data indicates that twice as many invertebrates are emerging from herbicide-treated habitat compared to other habitat types. Further, total aerial insectivore abundance was 54.5% higher in herbicide-treated habitat and 35.5% higher in resident habitat compared to invaded habitat. Barn Swallow specifically preferred herbicide-treated habitat, as abundance was 123% higher compared to invaded habitat. We conclude that efforts to eradicate invasive P. australis and restore wetland vegetation provide improved foraging habitat for at-risk aerial insectivore birds, most likely by increasing the quantity of invertebrate prey.

Restoring Least Bell’s Vireo habitat across California’s diverse ecosystem by adjusting proven methods from the Central Valley

Least Bell’s Vireos declined dramatically as the river processes which create and maintain vireo habitat were degraded through land conversion and flood control projects, reducing California’s population to 300 breeding pairs concentrated in San Diego by 1986. In response, a riparian restoration program in California’s Central Valley created thousands of acres of habitat, successfully attracting active nesting. Climate, topography, and other conditions facilitate rapid, cost-effective riparian restoration in this agricultural community; however, birds must disperse long distances from their current range to reach this habitat. To facilitate population growth in existing Southern California populations and thereby drive dispersal to the species’ historic range, River Partners adapted Central Valley horticultural restoration methods to the rivers of Southern California. Regional ecological differences (water availability), socio-political differences (risk perception, labor availability), and differing landscape context (urbanization, predation pressures) were incorporated into design and implementation. We used high-efficiency drip irrigation to reduce water use, delivering sufficient water to support rapid establishment and growth of potted stock and cuttings while limiting establishment of seeded understory species compared to Central Valley techniques. Stakeholder outreach drove site design and maintenance in this highly visible restoration context, impacting costs and development of future projects to a greater extent than in other regions. Although Least Bell’s Vireo quickly dispersed to newly restored riparian vegetation and attempted breeding in Southern California, continued refinement of restoration techniques could address variation by site and rain year of robust understory establishment, threats of nest parasitism and predation, and deeper understanding of prey resources.

Accelerating the science and practice of agricultural stream restoration in the Great Lakes Basin (Canada) and Canterbury (Aotearoa, New Zealand)

The solution for water quality and ecosystem health issues in freshwater ecosystems lies on the land through a suite of measures and coordinated activities at individual, community and watershed scales. This is especially clear for human-impacted, agricultural landscapes where individual farm actions have the potential to address and mitigate the losses of soil organic matter, nutrients and other run-off. Rather than a single solution, the reality is that a toolbox of approaches is required from farm field to tile-drain, and from headwaters to downstream waterbodies. Individual actions therefore rely on coordination and robust evidence. Here I present two case studies of aligned science-practice across lowland agricultural streams: one in Canterbury, Aotearoa New Zealand, and another in the Laurentian Great Lakes Basin of North America/Turtle Island. Shared between these examples were a commitment to engaging in local communities, from farmers to Indigenous stewards, and a broad range of practitioners, agencies and community groups. We engaged in a reciprocal process of knowledge co-production and coinnovation of possible solutions. Notably, the Canterbury Waterway Rehabilitation Experiment (CAREX), was a five-year region-scale experiment on waterways located on privately owned farms. The CAREX approach was then adapted for the local socio-ecological context of agricultural watersheds in southwest Ontario, Canada. This talk will illustrate how community responsive, local-context driven approaches have been crucial to accelerating and coordinating science and actions on the ground, and will be the critical factors underpinning successful freshwater restoration on local to global scales.

Freshwater ecosystem restoration in La Mauricie National Park: 16 years of ecological gains and the rewriting of the territory’s human occupation

A century and a half of logging and log driving prior to the creation of La Mauricie National Park have caused significant degradation of freshwater ecosystems. Some sixty log drive dams at lakes outlets altered water levels, hydric regimes and fish movement. In many locations, logs sank or washed up along shores, further
altering riparian and lake habitats. The dismantling of 20 dams and the removal of 110,000 logs from lakes in the last 16 years restored many water regimes and lake habitats in the park. Beyond these ecological gains, Resource Conservation team wanted to evaluate the resilience of riparian vegetation and the establishment of native or exotic species on newly exposed banks. The vegetation of lakes with dam removal 3, 4 and 16 years earlier was assessed and compared with a control lake. Using randomly
positioned transects, the study showed: 1) the presence of native plant species only, 2) the establishment of a secondary succession after 3 years, and 3) similar vegetation structure and composition after 16 years compared to the control.
The restoration work also allowed to make important archeological and historical discoveries in the area. The recovery of lake water levels has also revealed new paleohistoric occupation sites, demonstrating a more easterly human presence on the territory than previously assumed. Dendrochronological analysis of dam’s logs revealed an industrial scale log driving activity half a century before previously thought. The ecological restoration of lakes in La Mauricie National Park significantly improved the ecological integrity of freshwater ecosystems while allowing the establishment of native riparian vegetation, contributing to human history and improving beach access to park visitors.

Mitigation Approaches to Fund Stream Restoration Projects

Stream restoration continues to grow in popularity throughout North America. The practice of stream restoration has really taken off since the 1990’s particularly in the eastern United States and has been significantly funded through the mitigation process, which typically involves onsite mitigation or off-site mitigation as required by Sections 401 and 404 of the Clean Water Act. In the case of off-site mitigation, this is normally accomplished through the use of mitigation banks or in-lieu fees (ILF). There are advantages/disadvantages to each approach to mitigation, however the overwhelming advantage of each type of mitigation approach is that it creates a funding stream to pay for the restoration of stream impairments, which could be potentially replicated by other countries to help fund restoration projects. The author has been personally involved in on-site mitigation projects as well as off-site mitigation projects through mitigation banks and ILF programs. On-site mitigation can often be advantageous because it results in restoration of a stream that is directly being impacted. Offsite mitigation through mitigation banks and ILF programs also have advantages because they provide a means to pool mitigation dollars together so that larger more comprehensive stream restoration can be completed on a larger watershed scale. There are times when each form of mitigation represents the most viable alternative to accomplish restoration goals. The key is to develop and structure a mitigation program where each form of mitigation can be used as an option when appropriate.
This talk will focus on the various forms of mitigation practices and will provide case studies of on-site, mitigation banks and ILF mitigation projects. The talk will focus on mitigation drivers, different approaches to accomplish mitigation goals, and advantages/disadvantages of the various forms of mitigation to achieve restoration goals.

Natural infrastructure presents opportunity to scale river ecosystem restoration

River ecosystems are disproportionately important to biodiversity and in provision of services but have been substantially degraded globally by the concentration of agriculture, transportation and development in valley bottoms. At the same time, the impact of river ecosystem restoration efforts to date have been hampered by an over-emphasis on stabilization and in-channel remedies. River restoration is not meeting the scale and scope of impacts and challenges. Recent advancements in restoration practice and river management offer new approaches to improve restoration effectiveness and also serve as natural infrastructure to address increasing risks and impacts of climate change. As traditional gray infrastructure ages and fails under increasing climate stress, natural infrastructure offers an opportunity to rebuild with improved understanding of the value of nature. River valley bottoms, including source-water wetlands and riverscape floodplains, are the critical natural infrastructure areas deserving investments in protection and restoration to meet global water security and climate adaptation challenges. The marriage of practical, cost-effective, long-term climate adaptation solutions (i.e., natural infrastructure) with emerging restoration strategies (i.e., “freedom space”) can create opportunity to address the triple challenge of addressing loss of biodiversity and ecosystem services, improving climate resilience, and providing water security for human populations.

Practitioner and Science-Based Restoration Efforts On The Little Colorado River

Climate change-driven temperature and precipitation shifts can be best experienced in the American southwest— invasive plants steadily replace native plant habitat, surface and ground water resources are on the decline, and wildfire impacts are increasing in severity and frequency. This is especially true of the lower Little Colorado River (LCR) watershed—one of the most degraded riparian systems in this region. The Little Colorado River Valley Conservation Area (LCRVCA) spans 16 miles of intermittent river and includes almost 17,000 acres south of Cameron, AZ, and north of Wupatki National Monument within CO Bar Ranch—a part of privately owned and operated Babbitt Ranches. Restoration efforts within the LCRVCA embrace a locally-driven approach to restoring degraded riparian habitat along the lower LCR that can be adopted by other regional land managers and organizations. Utilizing American Conservation Experience (ACE) conservation crews, with assistance from the Landsward Foundation, Northern Arizona University’s Merriam-Powell Center for Environmental Research, Arizona Game and Fish Department, and Arizona’s Department of Forestry and Fire Management, on-the-ground restoration work is carried out effectively through a combination of practitioner-based knowledge, science-based research, and adaptive management. Goals and results of this on-going project include mitigation of invasive plant competition, creating open space for native plant recruitment and plantings, protecting remnant cottonwood stands from wildfire, and enhancing wildlife refugia. Project-related benefits include monitoring data that will inform and fortify successful land management strategies while proactively dealing with the challenges that are encountered on this rugged, hot, and dry project site.

Application of organic and mineral amendments to reduce metal mobility and revegetate acidic mine tailings

Mexico has millions of tons of abandoned tailings throughout the country. Biochar is an interesting candidate to aid in tailing stabilization due to its properties. Gasification and Kon-Tiki oven pyrolysis are technologically-contrasting ways to produce low-cost biochar from various feedstocks. However, nutrient-poor tailings require a source of nutrients usually not provided by biochar. Compost is an organic alternative to provide said nutrients. A 6-month pot experiment sown with ryegrass was conducted using a pH 2 mine tailing mixed with organic amendments (gasification and pyrolysis biochar and three types of compost and co-compost) in 7 and 30% doses with or without added dolomite to attain a pH of 6. The objective was to evaluate biochar-based organic amendments’ potential to improve the substrate’s properties to favor the establishment of a vegetative cover and to reduce metal mobility (As, Cd, Cr, Cu, Ni, Zn) and uptake. Biochar and compost alone reduced metal mobility though this reduction was greater in the presence of dolomite. Grass germinated only in the presence of dolomite even without organics, though development was greater in the presence of organics and increased with increasing dose. Leaching of irrigation water was lower in treatments with dolomite as a result of vegetative development. Biomass gasification and composting of organic wastes may be a suitable alternative to obtain carbon-negative energy, effectively manage organic wastes and produce organic amendments suitable for use in land reclamation upon mine closure, reducing metal mobility and aiding in the physical stabilization of materials.

Can fungal communities restore native trees on reclaimed substrates containing hydrocarbons?

Landscapes mined for bitumen must be reclaimed and revegetated to restore self-sustaining ecosystems in the boreal forest of western Canada. Residual hydrocarbons can be present in reclaimed landforms, and it is unclear what effect they may have on establishing native vegetation. In this same region, forests occur on natural surficial bitumen deposits and some vegetation persists on abandoned ore piles; these locations provide unique opportunities to investigate whether we can leverage interactions between soil fungi and roots to establish trees on reclaimed sites. To screen fungi promoting seedling growth on substrates containing hydrocarbons, we used Illumina sequencing to survey soil fungi on these sites in addition to forests free of bitumen. Next, we grew Populus tremuloides and Pinus banksiana, two native tree species used in revegetation, in substates used in reclamation either inoculated or not with soils collected from our survey. We found that in abandoned ore piles there were more pathogens and unknown taxa, and fewer ectomycorrhizal fungi compared with communities present in naturally occurring soils with and without bitumen. In our greenhouse experiment, we found that the presence of hydrocarbons reduced growth of P. tremuloides and P. banksiana. However, only P. banksiana was sensitive to origin of soil inoculum; growth was highest when inoculated with soils from forests free of bitumen while inoculum from forests on natural bitumen deposits and abandoned ore piles had no effect. Our results show soil inoculum may be an effective method of establishing some tree species on reclaimed areas.

Constraints and Perspectives of Combined Ecological Restoration and Phytoremediation on a Mediterranean Protected Area Contaminated with Heavy Metals

In the current context of ecosystem biodiversity and functionality erosion, combining ecological restoration and phytoremediation provides effective solutions for the management of metals and metalloids (MM) contaminated areas, by mitigating environmental contamination or avoiding contaminant dispersal, while restoring floristic biodiversity, soil, and their functionalities. This results in new challenges: (i) extending ecological restoration actions to manage highly degraded sites submitted to irreversible modifications, (ii) developing phytoremediation tools focusing on environmental-friendly methods that allow ecosystems to be dynamic and resilient, maintain their functions and support ecosystem services facing environmental changes. These aspects are mobilized in an ecological restoration trial which was set up in 2017 on a Mediterranean site contaminated with MM by using native plant species to restore plant and microbial communities, while providing an efficient MM stabilization in soil. After 3 years, an assessment of this operation success was done by modeling and considering 3 ecosystem compartments i.e soil, plant, and microorganisms. The results suggest that an ecological restoration trajectory is initiated, characterized by a partial permanent plant cover composed by planted native species and spontaneous local plant species which have colonized the experimental plots. However, there is no evidence of an improvement of soil health and phytostabilization efficiency. We hypothesized that this drastic Mediterranean environement constrains the recovery of native plant and microbial communities, which limit MM stabilization in soil. Thus, climatic parameters need to be integrated into the process understanding and taken into account in the restoration practices, especially in the current context of global warming