Showing papers in "Restoration Ecology in 2020"

A World of Possibilities: Six Restoration Strategies to support the United Nation's Decade on Ecosystem Restoration

Abstract: Ecological restoration is practiced worldwide as a direct response to the degradation and destruction of ecosystems. In addition to its ecological impact it has enormous potential to improve population health, socioeconomic well‐being, and the integrity of diverse national and ethnic cultures. In recognition of the critical role of restoration in ecosystem health, the United Nations (UN) declared 2021–2030 as the Decade on Ecosystem Restoration. We propose six practical strategies to strengthen the effectiveness and amplify the work of ecological restoration to meet the aspirations of the Decade: (1) incorporate holistic actions, including working at effective scale; (2) include traditional ecological knowledge (TEK); (3) collaborate with allied movements and organizations; (4) advance and apply soil microbiome science and technology; (5) provide training and capacity‐building opportunities for communities and practitioners; and (6) study and show the relationships between ecosystem health and human health. We offer these in the hope of identifying possible leverage points and pathways for collaborative action among interdisciplinary groups already committed to act and support the UN Decade on Ecosystem Restoration. Collectively, these six strategies work synergistically to improve human health and also the health of the ecosystems on which we all depend, and can be the basis for a global restorative culture.

Dormancy and germination: making every seed count in restoration

Abstract: From 50 to 90% of wild plant species worldwide produce seeds that are dormant upon maturity, with specific dormancy traits driven by species' occurrence geography, growth form, and genetic factors. While dormancy is a beneficial adaptation for intact natural systems, it can limit plant recruitment in restoration scenarios because seeds may take several seasons to lose dormancy and consequently show low or erratic germination. During this time, seed predation, weed competition, soil erosion, and seed viability loss can lead to plant re‐establishment failure. Understanding and considering seed dormancy and germination traits in restoration planning are thus critical to ensuring effective seed management and seed use efficiency. There are five known dormancy classes (physiological, physical, combinational, morphological, and morphophysiological), each requiring specific cues to alleviate dormancy and enable germination. The dormancy status of a seed can be determined through a series of simple steps that account for initial seed quality and assess germination across a range of environmental conditions. In this article, we outline the steps of the dormancy classification process and the various corresponding methodologies for ex situ dormancy alleviation. We also highlight the importance of record‐keeping and reporting of seed accession information (e.g. geographic coordinates of the seed collection location, cleaning and quality information, storage conditions, and dormancy testing data) to ensure that these factors are adequately considered in restoration planning.

Seed storage: maintaining seed viability and vigor for restoration use

Abstract: Effective seed storage after sourcing (harvesting or purchasing) is critical to restoration practitioners and native seed producers, as it is key to maintaining seed viability. Inadequate seed storage can lead to a waste of both natural and economic resources when seeds of poor quality are sown. When working with native species with unknown storage behavior, general assumptions can be made based on studies on related species, and standard practices may be applied with caution; however, an investigation should be conducted to understand if specific storage requirements are needed and for how long seeds can be stored before they lose significant viability. In this paper of the Special Issue Standards for Native Seeds in Ecological Restoration, we provide an overview of the key concepts in seed storage and the steps to take for effective storage of native seeds for restoration use.

Functional traits and ecosystem services in ecological restoration

Abstract: The application of a functional trait‐based approach to ecological restoration is receiving growing attention worldwide, but lack of knowledge on functional traits and how they link to ecosystem services imposes a major barrier to operationalize such approach. Synthesizing the existing knowledge on functional trait‐based restoration is thus a timely and important challenge. We systematically reviewed the literature to assess how ecosystem services are associated to functional traits across organisms, ecosystem types, and continents. We also assessed the existing trait‐based frameworks to target ecosystem services in restoration ecology. Then, we discussed future perspectives for the field, especially the challenges of applying trait‐based frameworks in megadiverse tropical ecosystems, which have ambitious restoration commitments. Most papers focused on plants (72%), terrestrial habitats (69%), and non‐tropical ecosystems (68%) and monitored ecosystem services and functional traits after restoration started rather than using them as previous targets. Only 12% of the papers targeted the restoration of both services and traits a priori, and 3.8% presented a clear trait‐based framework to target ecosystem services in restoration. The possibility of selecting alternative subsets of complementary species in their provisioning of ecosystem services should make functional restoration more feasible than traditional approaches in species‐rich tropical ecosystems. With this review and our critical insights on the perspectives of applying functional trait‐based restoration widely, we hope to assist broad‐scale restoration programs to obtain higher levels of benefits for nature and human well‐being per unit of area undergoing restoration, going beyond the area‐based approach that has dominated restoration commitments.

International principles and standards for native seeds in ecological restoration

Abstract: The growing demand for native seeds in ecological restoration and rehabilitation, whether for mining, forest, or ecosystem restoration, has resulted in a major global industry in the sourcing, supply, and sale of native seeds. However, there are no international guidance documents for ensuring that native seeds have the same standards of quality assurance that are regular practice in the crop and horticultural industries. Using the International Principles and Standards for the Practice of Ecological Restoration as a foundation document, we provide for the first time a synthesis of general practices in the native seed supply chain to derive the Principles and Standards for Native Seeds in Ecological Restoration (“Standards”). These practices and the underpinning science provide the basis for developing quality measures and guidance statements that are adaptable at the local, biome, or national scale. Importantly, these Standards define what is considered native seed in ecological restoration and highlight the differences between native seeds versus seeds of improved genetics. Seed testing approaches are provided within a logical framework that outline the many different dormancy states in native seed that can confound restoration outcomes. A “pro‐forma” template for a production label is included as a practical tool that can be customized for local needs and to standardize reporting to end‐users on the level of seed quality and germinability to be expected in a native seed batch. These Standards are not intended to be mandatory; however, the guidance statements provide the foundation upon which regulatory approaches can be developed by constituencies and jurisdictions.

Collection and production of native seeds for ecological restoration

Abstract: The global push to achieve ecosystem restoration targets has resulted in an increased demand for native seeds that current production systems are not able to fulfill. In many countries, seeds used in ecological restoration are often sourced from natural populations. Though providing seed that is reflective of the genetic diversity of a species, wild harvesting often cannot meet the demands for large‐scale restoration and may also result in depletion of native seed resources through over harvesting. To improve seed production and decrease seed costs, seed production systems have been established in several countries to generate native seeds based on agricultural or horticultural production methods or by managing natural populations. However, there is a need to expand these production systems which have a primary focus on herbaceous species to also include slower maturing shrub and tree seed. Here we propose that to reduce the threat of overharvest on the viability of natural populations, seed collection from natural populations should be replaced or supplemented by seed production systems. This overview of seed production systems demonstrates how to maximize production and minimize unintended selection bias so that native seed batches maintain genetic diversity and adaptability to underpin the success of ecological restoration programs.

Revegetation of urban green space rewilds soil microbiotas with implications for human health and urban design

Abstract: Jacob G. Mills, Andrew Bissett, Nicholas J.C. Gellie, Andrew J. Lowe, Caitlin A. Selway, Torsten Thomas, Philip Weinstein, Laura S. Weyrich, Martin F. Breed

Myth-busting tropical grassy biome restoration

Abstract: The historical focus in research and policy on forest restoration and temperate ecosystems has created misunderstandings for the restoration of tropical and subtropical old-growth grassy biomes (TGB). Such misconceptions have detrimental consequences for biodiversity, ecosystem services, and human livelihoods in woodlands, savannas, and grasslands worldwide. Here, we demystify TGB restoration myths to promote a positive agenda to increase the likelihood of success of ambitious landscapescale restoration goals of nonforest ecosystems. The 10 TGB restoration myths are: (1) grasslands originate from degraded forests, (2) tree cover is a reliable indicator of habitat quality, (3) planting trees is always good for biodiversity and ecosystem services, (4) grasslands are biodiversity-poor and provide few ecosystem services, (5) enhancing plant nutrition is needed in restoration, (6) disturbance is detrimental, (7) techniques used to restore temperate grasslands also work for TGB, (8) grasslands represent early stages of forest succession, (9) grassland restoration is only about grasses, and (10) grassland restoration is fast. By demystifying TGB restoration, we hope that policymakers, scientists, and restorationists come to understand and embrace the value of these ecosystems and are motivated to establish policies, standards, indicators, and techniques that enhance the success of TGB restoration. We must abandon misperceptions and misunderstandings of TGB ecology that result in ill-conceived policies and build an informed and compelling global ecosystem restoration agenda that maintains and improves the well-being of all inhabitants of grassy biomes.

Seed use in the field: delivering seeds for restoration success

Abstract: Seed delivery to site is a critical step in seed‐based restoration programs. Months or years of seed collection, conditioning, storage, and cultivation can be wasted if seeding operations are not carefully planned, well executed, and draw upon best available knowledge and experience. Although diverse restoration scenarios present different challenges and require different approaches, there are common elements that apply to most ecosystems and regions. A seeding plan sets the timeline and details all operations from site treatments through seed delivery and subsequent monitoring. The plan draws on site evaluation data (e.g. topography, hydrology, climate, soil types, weed pressure, reference site characteristics), the ecology and biology of the seed mix components (e.g. germination requirements, seed morphology) and seed quality information (e.g. seed purity, viability, and dormancy). Plan elements include: (1) Site treatments and seedbed preparation to remove undesirable vegetation, including sources in the soil seed bank; change hydrology and soil properties (e.g. stability, water holding capacity, nutrient status); and create favorable conditions for seed germination and establishment. (2) Seeding requirements to prepare seeds for sowing and determine appropriate seeding dates and rates. (3) Seed delivery techniques and equipment for precision seed delivery, including placement of seeds in germination‐promotive microsites at the optimal season for germination and establishment. (4) A monitoring program and adaptive management to document initial emergence, seedling establishment, and plant community development and conduct additional sowing or adaptive management interventions, if warranted. (5) Communication of results to inform future seeding decisions and share knowledge for seed‐based ecological restoration.

Seed planning, sourcing, and procurement

Abstract: Ensuring the availability of adequate seed supplies of species and sources appropriate for restoration projects and programs necessitates extensive science‐based planning. The selection of target species requires a review of disturbance conditions and reference areas, development of a reference model, and consideration of specific objectives, timeframes, available resources, and budgets as well as the performance of prospective species in past restoration efforts. Identification of seed sources adapted to site conditions is critical to provide for short‐term establishment and long‐term sustainability. Seed zones and plant movement guidelines provide tools for sourcing plant materials with reduced risk of maladaptation. A seed zone framework also facilitates seed use planning and contributes to stability and predictability of the commercial market, thereby reducing costs and improving the availability of adapted seed supplies. Calculating the amount of seed required for each species is based on seed quality (viability, purity), seed weight, expected seedling establishment, and desired composition of the seeding. If adequate collections from wildland stands are not feasible, then seed increase in seed fields or use of nursery stock may be warranted. Adherence to seed collection and seed production protocols for conserving genetic diversity is critical to protect genetic resources and buffer new seedings and plantings against environmental stressors. Maintenance of genetic diversity becomes even more critical considering current or expected climate change impacts. Collaboration and partnerships can benefit seed selection and procurement programs through sharing of information, coordination in project planning, and increasing the availability of native seed.

A new era in forest restoration monitoring

Abstract: Monitoring ecological restoration has been historically dependent on traditional inventory methods based on detailed information obtained from field plots. New paradigms are now needed to successfully achieve restoration as a large‐scale, long‐lasting transformative process. Fortunately, advances in technology now allow for unprecedented shifts in the way restoration has been planned, implemented, and monitored. Here, we describe our vision on how the use of new technologies by a new generation of restoration ecologists may revolutionize restoration monitoring in the coming years. The success of the many ambitious restoration programs planned for the coming decade will rely on effective monitoring, which is an essential component of adaptive management and accountability. The development of new remote sensing approaches and their application to a restoration context open new avenues for expanding our capacity to assess restoration performance over unprecedented spatial and temporal scales. A new generation of scientists, which have a background in remote sensing but are getting more and more involved with restoration, will certainly play a key role for making large‐scale restoration monitoring a viable human endeavor in the coming decade—the United Nations' decade on ecosystem restoration.

“Active” and “passive” ecological restoration strategies in meta‐analysis

Abstract: One of the means of creating a more robust methodology for ecological restoration involves reducing the gap between ecological theory and restoration practices A common strategy to do so is using meta‐analysis to understand key drivers of restoration outcomes “Active” and “passive” is a dichotomy often used to separate restoration strategies in such meta‐analyses We investigate previously raised concerns about selection bias and subjective categorization of strategies We promote a paired experimental design in future empirical research and propose the use of three categories of restoration strategy in lieu of “passive” and “active” to alleviate inconsistency in definitions and categorization

Practices of biological soil crust rehabilitation in China: Experiences and challenges

Abstract: Biological soil crusts (biocrusts) are a central component of dryland ecosystems. However, they are highly vulnerable to disturbance and natural recovery may be slow. Therefore, finding ways to enhance the reestablishment of biocrusts after disturbance has been of great interest to researchers. This article provides a review of the laboratory cultivation and field inoculations of biocrust materials in China (mostly published in Chinese). Larger filamentous cyanobacteria (e.g. Microcoleus) are relatively easy, although slow, to grow in culture compared to other biocrust components. Thus, most researchers have focused their efforts on the cyanobacteria and a few species of mosses that are also easily grown but at smaller scale. For all the studies, a small amount of biocrust material was collected and its biomass enhanced under controlled conditions. However, the enhancement was done using various methods and techniques in different regions. These materials were then applied to disturbed field sites, again with various methods. Results show that keeping the inoculated soil surface wet for some time period after inoculation was crucial for restoration success. Cyanobacterial establishment was improved by installing automatic sprinkling using micro‐irrigation techniques and/or physical structures that reduced sediment moving onto the inoculated area. Experimental applications in China showed that cyanobacteria can be successfully inoculated at a large scale (hundreds of ha). Moss inoculation, on the other hand, was only accomplished at a small scale (several m²). To assess whether biocrust restoration can enhance the establishment of a self‐supporting ecosystem, further research is needed on how inoculation affects vegetation diversity and structure and ecological processes.

Symbiodiniaceae probiotics for use in bleaching recovery

Abstract: Coral reefs are currently under threat as a consequence of local and global stressors, in particular, mass coral bleaching induced by climate warming. In conjunction with global cuts to carbon emissions, active restoration interventions are being investigated as an additional option to buy time while these stressors are mitigated. One intervention with the potential to improve recovery during or postbleaching involves the addition of probiotic treatments, that is the addition of microorganisms that provide benefits to the host. Fragments of the branching coral, Acropora millepora, were experimentally exposed to a bleaching event coupled with the inoculation of Symbiodiniaceae probiotics (Durusdinium trenchii and Cladocopium goreaui) to determine if these probiotic treatments could ameliorate bleaching related stress and mortality. Fragments inoculated with C. goreaui and exposed to 32 degrees C for 6 days exhibited significantly less mortality (9.1 +/- 5%) compared to corals exposed to 32 degrees C without probiotics (66.7 +/- 8%) or with D. trenchii (41.7 +/- 9%). Fragments in the C. goreaui probiotic treatment also bleached less and exhibited the highest photosynthetic efficiency compared to fragments inoculated with the D. trenchii at 32 degrees C. Internal transcribed spacer-2 amplicon sequencing did not detect the inoculated D. trenchii and C. goreaui cells within A. millepora tissues at the end of the experiment, suggesting the corals did not reestablish symbiosis but instead used inoculated cells as a nutritional supplement, although other factors such as shuffling conditions may have had an effect. This study highlights that nutritional supplementation can possibly aid coral resilience to temperature stress, though a far more detailed understanding of the factors that influence host regulation during symbiosis establishment is required.

Be nimble with threat mitigation: lessons learned from the reintroduction of an endangered species

Abstract: This research is supported by the Australian Government’s National Environmental Science Program through the Threatened Species Recovery Hub

Ensuring seed quality in ecological restoration: Native seed cleaning and testing

Abstract: Seeds are a critical and limited resource for restoring biodiversity and ecological function to degraded and fragmented ecosystems. Cleaning and quality testing are two key steps in the native seed supply chain. Optimizing the practices used in these steps can ensure seed quality. Post‐collection handling of seeds can have a profound impact on their viability, longevity in storage, and establishment potential. The first section of this article describes seed cleaning, outlines key considerations, and details traditional and novel approaches. Despite the growth of the native seed industry and the need for seed quality standards, existing equipment and standards largely target agricultural, horticultural, and commercial forestry species. Native plant species typically have complex seed traits, making it difficult to directly transfer existing cleaning and quality standards to these species. Furthermore, in ecological restoration projects, where diversity is valued over uniformity crop standards can be unsuitable. We provide an overview and recommendations for seed quality testing (sampling, purity, viability, germinability, vigor), identity reporting, and seed transfer as well as highlight the need to implement internationally recognized standards for certification for native seeds. Novel and improved cleaning and testing methods are needed for native species from a range of ecosystems to meet the challenges and goals of the United Nations Decade on Ecosystem Restoration. The guidelines outlined in this article along with others in the Special Issue of Restoration Ecology “Standards for Native Seeds in Ecological Restoration” can serve as a foundation for this critical work.

Lack of adequate seed supply is a major bottleneck for effective ecosystem restoration in Chile: Friendly amendment to Bannister et al. (2018).

Abstract: We argue that the need for a quality seed supply chain is a major bottleneck for the restoration of Chile's native ecosystems, thus supplementing the list of bottlenecks proposed by Bannister et al. in 2018. Specifically, there is a need for defining seed transfer zones, developing standards and capacities for properly collecting and storing seeds, reducing information gaps on seed physiology and longevity, and implementing an efficient seed supply chain with certification of seed origin and quality. Without such capacities, countries are unlikely to meet their restoration commitments. Although we focus on bottlenecks in Chile, the issues we raise are relevant to other countries and thus the global agenda for ecological restoration.

From marine deserts to algal beds: Treptacantha elegans revegetation to reverse stable degraded ecosystems inside and outside a No‐Take marine reserve

Abstract: Canopy‐forming algae play a key role in temperate coastal ecosystems sustaining complex habitats that provide food and refuge for rich associated biotic communities. These macroalgae are in decline in many coastal areas, where overgrazing by herbivores can lead to the loss of these highly structured and diverse habitats toward less complex sea urchin barren grounds. Once established, low productive barren grounds are considered stable states maintained by several positive feedback mechanisms that prevent the recovery of marine forests. To revert this global decline, restoration efforts and measures are being encouraged by EU regulations and local actions. Here, we tested the success of active revegetation techniques as a tool to promote functional and productive Treptacantha elegans forests in sea urchin barren grounds under different restoration strategies (active, and combined active with passive strategies). Active revegetation was performed in 6 barren grounds, 3 located inside a Mediterranean No‐Take marine reserve (active and passive strategy) and 3 outside (active strategy alone), following a three‐step protocol: (1) sea urchin population eradication, (2) seeding with Treptacantha elegans, and (3) enhancement of T. elegans recruitment. Revegetation success was assessed 1 year later in the six barren grounds, but was only achieved after combining active with passive restoration strategies. Our results encourage revegetation of barren grounds to shift from less productive habitats to complex T. elegans forests, highlight the potential of the combined passive and active restoration strategies, as well as the important role of marine reserves not only in conservation but also in ecological restoration.

Mixing source populations increases genetic diversity of restored rare plant populations

Abstract: The genetic diversity of germplasm used in reintroduction and restoration efforts can influence how resulting populations establish, reproduce, and evolve over time, particularly in disturbed and changing conditions. Regional admixture provenancing, mixing seeds derived from multiple populations within the same region as the target site, has been suggested to produce genetically diverse germplasm. Yet little empirical evidence shows how genetic diversity in germplasm resulting from this approach compares to source populations, or how it varies in restored populations. Here, we use neutral molecular markers to follow genetic diversity through production and use of germplasm when mixing multiple source populations in nursery production beds. Castilleja levisecta is a rare species experiencing inbreeding depression in remaining populations, with a federal recovery plan requiring the re‐establishment of populations in areas where it has been extirpated. Specifically, we track diversity from wild‐collected source populations through different production approaches and reintroductions using two propagule types. We show that measures of genetic diversity, inbreeding, and relatedness change during the production and use of material produced with a regional admixture provenancing approach, with the step at which source populations are mixed and germplasm type used influencing whether all source populations are equally represented. While genetic diversity increased throughout the process, inbreeding and relatedness increased in nursery production beds but decreased in reintroductions, with the lowest inbreeding and relatedness in populations restored using seeds rather than plugs. The results highlight the importance of taking an integrated approach informed by research when planning and implementing reintroductions with mixed‐source germplasm.

Restoring mussel beds in highly dynamic environments by lowering environmental stressors

Abstract: Restoration of coastal ecosystem engineers that trap sediment and dampen waves has proven to be difficult, especially in the wave‐exposed and eroding areas where they are needed the most. Environmental stressors, such as hydrodynamic stress and predation, can only be overcome if transplanted organisms are able to establish self‐facilitating feedbacks. We investigate if the artificial lowering of multiple environmental stressors can be used to give transplanted juveniles the opportunity to form a self‐sustainable system and thereby increase their long‐term survival on wave‐exposed and eroding shores. We designed a large field experiment using juvenile mussels (Mytilus edulis ) as model species on a wave‐exposed tidal flat in the Oosterschelde estuary (the Netherlands). We tested if the environmental stress caused by a high predation pressure and wave‐driven dislodgement could be reduced by a combination of artificial structures such as fences (to exclude predatory crabs), attachment substrates (such as coir‐net or oyster shells) and breakwaters. Despite a low overall mussel survival (29%), we found that under strong hydrodynamic conditions, experimental fences and attachment substrates increased the retention of transplanted mussel seed. However, modification of local hydrodynamic conditions using breakwaters did not improve mussel coverage preservation. Overall, this study highlights the potential of using techniques that lower multiple environmental stressors to create a window of opportunity for establishment in highly dynamic ecosystems.

Integrated climate sensitive restoration framework for transformative changes to sustainable land restoration

Abstract: Sustainable land restoration is the key to restore degraded land, halt biodiversity loss and reinstate ecosystem services for human well‐being Restoration needs to be planned and conducted with due recognition to growing climate uncertainty with an evolved understanding about the future restoration targets Present opinion article attempts to provide an overview on Integrated Climate Sensitive Restoration Framework that recognizes the local participation in mapping degraded lands, identification of species for supporting species modelling to better understand climate uncertainty Involvement of citizen science based restoration monitoring tools can contribute to big data analytics for ecological monitoring and policy support The Framework potentially helps in sustainable land restoration by transformative changes for achieving UN decade on Ecosystems Restoration (2021–2030), SDGs 15 and addressing the post 2020 Global Biodiversity Framework However, to realize the success, climate finance mechanisms to drive restoration should be seriously considered for reducing bias and enhancing opportunities of equitable sharing in the era of corruption, authoritarianism and regulatory capture