Resource Database

Conserving Shellfish Reefs – A Systematic Review Reveals the Need to Broaden Research Efforts

Globally shellfish reefs have experienced unprecedented declines from historical levels, imperilling the surrounding ecosystems and the services they provide. Shellfish conservation and restoration projects have emerged to combat and reverse this decline but are hindered by a scattered knowledge base and a lack of evidence-based best practice. To address this concern, we conducted a systematic review of English-language peer-reviewed articles studying the impacts of conservation-based actions on reef-building bivalves. A comprehensive search identified 281 relevant articles for the review. Articles were then categorized to establish the temporal and geographic extent of shellfish reef conservation research, quantify collaboration within the field, and develop a systematic map of the distribution of evidence across intervention and outcome categories. The results confirm a substantial increase in shellfish reef research with 72% of articles published since 2010. However, this evidence base is skewed, with 80% of research occurring in the United States and Northern Europe, 71% only on oysters, and 58% by only academia-affiliated authors. The systematic map of linkages and gaps also reveals disparities in the evidence base, as ecological interventions and outcomes are undertaken and measured at a far greater rate than social interventions and outcomes, despite evidence that social aspects are critical components of conservation work. To ensure future restoration practitioners have evidence that is relevant to the circumstances of their projects, this evidence base needs to be diversified and we offer recommendations on reprioritizations for future research as well as a comprehensive database of existing shellfish conservation papers.

Water Crisis: Lessons Learned

Join South Africa’s Water Research Commission (WRC) as they discuss the challenges associated with water security in the Western Cape region and around the country. Hear about how they have overcome the difficulties posed by the recent devastating drought.

Germination strategies of selected Kuwaiti desert plants and their implications for dryland restoration

Desert plants use a number of strategies to survive in arid environments, which are characterized by extremely high temperature, intense radiation, strong winds, low and erratic rainfall, high evaporation rates, soil erosion, and lower nutrient availability. These species produce certain structures that help in seed dispersal to suitable microsites and/or regulate their germination response to prevailing conditions. Some species also produce heteromorphic seeds or maintain aerial seed banks to cope with extreme environmental conditions. The adaptive mechanisms in three of Kuwait’s native plants, namely, Farsetia aegyptia Turra (presence mucilage), Seidlitzia rosmarinus Boiss. (presence of wings) and Calligonum comosum (heteromorphic seeds) were studied and their germination behavior under different temperature and light regimes and elevated salinity conditions was determined in the present study. Irrespective of incubation temperature regimes and photoperiods, de-winged S. rosmarinus seeds germinated better (76-88% total germination) than intact seeds (24-41%) with the low temperature regime (20/15 °C) resulting in 10% higher germination (85-88% vs. 76-78%). Although the presence of mucilage and thermoperiod did not affect the germination, longer storage significantly increased the germinabilty of C. comosum seeds. Increasing salinity levels decreased the germination of all three species, but ungerminated seeds were able to germinate when the salinity stress was alleviated. These mechanisms allow them to minimize the impact of adverse habitat conditions and maintain seed viability. The implications of these adaptive mechanisms for dryland restoration will be discussed in this paper.

The importance of root hydraulic function for the survival of planted seedlings in dry conditions

Root function and growth is critically important to the survival and performance of planted seedlings, especially in ecosystems with seasonal dry periods. In many restoration sites, limited access to soil moisture has the potential to reduce outplanting success. Root hydraulic conductance, Kr, measures the capacity of a plant’s root system to supply the shoot with water. Kr can be impacted by planting practices, environmental conditions, and subsequent seedling growth. Using techniques from plant hydraulic physiology, we conducted a greenhouse experiment to measure changes in root hydraulic conductance in Douglas-fir seedlings (Pseudotsuga menziesii) after transplanting. Douglas-fir is a key forest species in the western United States and planted Douglas-fir seedlings must survive summers with very little rainfall. We found that Kr increased linearly with seedling leaf area in well-watered conditions. However, in water-limited conditions, Kr did not increase as seedlings grew new needles, which in turn reduced photosynthesis and lowered total seedling biomass. These results indicate that water limitation changes root function even before the seedlings experience xylem cavitation and in ways that impact the water supply to the shoot. From these conclusions, we emphasize the importance of restoration practices that can mitigate water stress after planting, such as the timing of planting, site preparation methods that reduce competition for soil water, and nursery growing and handling protocols that promote high capacity for root growth. Careful attention to root quality, understanding root function, and taking actions to ensure root growth will be important for the success of restoration with planted seedlings.

Using dispersal and germination life traits of native vegetation to promote ecological restoration in southern New Caledonia

New Caledonia is considered to be one of the main “hotspots” of biological conservation. Its exceptional level of endemism is increasingly threatened by the expansion of human activities. One of the most important threats is habitat fragmentation due in part to fires and mine exploration on ultramafic massifs that erodes habitat quality. Natural environments affected must be restored to maintain the ecosystem services they provide. Over the past 40 years, revegetation techniques have aimed to reduce the impacts of erosion. However ecological restoration has only been pioneered in the past 15 years. Present research compliments previous studies and aims to (1) characterize dispersal and germination of plant species found in early successional maquis and forest mosaics on the Goro plateau in southern New Caledonia, (2) evaluate the trajectory of mine revegetation plantations based on the life traits of the species used from surrounding vegetation. A database was constructed and presents data dealing with 41 life-traits of 407 taxa found in the vegetation mosaic. In addition, an assessment restoration progress using the five-star recovery system developed by SER was conducted from surveys and measurements of both planted and colonizing vegetation. Finally, inventories of surrounding natural vegetation provided details of their structure and composition that highlight the ecological succession and permitted establishment of a local indigenous reference ecosystem. Recommendations based on results were provided to managers to assist in implementing ecological continuities projects including a list of candidate species to prioritize in future restoration programs.

Testing for evolutionary change in restoration: A genomic comparison between ex situ, native, and commercial seed sources of Helianthus maximiliani

North America’s grasslands are one of the most globally imperiled ecosystems and thus need restoration strategies that maintain evolutionary potential for persistence under rapidly changing conditions. However, the maintenance of evolutionary potential requires genetic variation for adaptive evolution. Thus, increasing our understanding for how preservation and propagation may modify genetic variation of material used in restoration will illustrate the important role evolutionary change may have influencing short- and long-term restoration success. A combination of evolutionary factors, including selection, demographic variation, and founder effects will influence the amount and type of genetic variation available in restoration material. Intentional or unintentional selection of restoration material may contribute to the evolution of seed sources, impacting performance and evolutionary potential following restoration. We examined genomic variation in Helianthus maximiliani, a perennial sunflower distributed across the Great Plains of North America that is commonly used in grassland restorations. We use next-gen sequencing (GBS) approaches to evaluate genomic variation within and among a combination of seed sources; including historical ex situ collections, native populations, and commercial seed sources. Our data suggest that genetic differences have evolved across seed source types. In particular, commercial seed sources exhibit significant genetic differentiation from both ex situ and native seed sources. Future work aims to tease apart the impact different evolutionary processes have had on the genomic structure of the different seed source populations. This work will include an evaluation of whether phenotypic variation in traits important to adaptation have evolved over time and in response to propagation.

State of the research: Using activated carbon in herbicide protection pods to simultaneously reseed desirable species and treat invasive annual weeds

Restoration of desirable plants can be challenging in dryland settings, and the challenge is compounded when competing exotic species are present. Pre-emergent herbicides are frequently used to reduce competition from exotic annual plants prior to seed-based restoration. After application, reseeding desirable species usually must wait up to a year or more until herbicide toxicity has waned, and this herbicide-fallow period necessitates additional site visits to reseed. Also, if rapid annual reinvasion occurs, there may be little benefit from herbicide application. Herbicide protection pod (HPP) technology allows for simultaneous seeding and herbicide application by protecting desirable seeds inside pods or pellets containing activated carbon, thereby eliminating herbicide-fallow periods and allowing for single-entry restoration approaches. This technology has shown promise in multiple laboratory and field experiments to date, but many important questions remain and are under investigation. We present a review of the technology, then summarize recent results and ongoing research with emphasis on 1) optimizing HPP efficacy via modifying size and formulation, 2) comparing different delivery methods, and 3) scaling up production. Optimal HPP formulation and geometry depends on seed size and species, and refinement can decrease cost and improve efficiency. Traditional seed-delivery systems may need modification to ensure maximum performance of this technology. Industrial mass-production will be crucial to scaling up but presents challenges in maintaining product quality. We highlight additional opportunities and challenges and propose goals and priorities for ongoing research of this developing technology, which could prove to be transformative for restoration of invaded drylands.

Tropical savanna restoration by direct seeding: Steps forward

International commitments set a target for Brazil to restore 12 million hectares of natural habitat of which 5 million hectares are within the Cerrado (savanna) region. To achieve such commitments, we need restoration methods that are cost-effective and practical at a large scale. Since 2012, we have tested and developed direct seeding techniques to decrease costs and improve restoration success on grasslands and savannas. More than 200 hectares have been direct seeded to restore areas in central Brazil. The direct seeding techniques have been applied by an increasing number of private and public companies to promote restoration. We were able to establish more than 70 native grasses, shrubs and trees species; and significantly changed soil cover from exotic to native species. However, many challenges persist, especially the control of African grass species, widely introduced for pasturelands that become aggressive invaders. We tested mechanical control of invasive grasses (IG) through repetitive soil plowing before direct seeding and the introduction of different functional groups. A mixture of native species with perennial grasses and fast-growing shrub and tree species improves restoration success, especially in less fertile soils where IG fitness is reduced. Mechanical control decreases IG but does not eliminate them, and it causes severe soil disturbances. The use of chemical control, even inside legally protected areas, is highly recommended to improve restoration success in tropical grasslands and savannas where shading by thick tree layer would eliminate IG but create inadequate restoration endpoints. Improving native species harvesting and seeding techniques is also essential.

A decade of direct seeding for forest restoration in the Brazilian Amazon, Cerrado, and Atlantic biomes

South Amazon forests have been highly deforested since the 1970’s. The Y Ikatu Xingu watershed campaign direct seeded 5 000 ha of forests from 2006 up to 2018. Direct seeding is considered a feasible, inexpensive, and effective method for ecological restoration with advantages that facilitate large-scale use, such as mechanized operations. Nevertheless, little is known about the successional trajectory of tropical forests restored through direct seeding. We sampled 72 direct seeded sites (1-10-y old), three seedling planted sites, and six natural regeneration sites, along a latitudinal gradient of 600 km in the state of Mato Grosso, Brazil. Sites began dominated by herbs and shrubs (green manure, short cycle leguminous), followed by 1 to 5 light-demanding tree species, while slow-growing species were present in the understory. After four years, direct-seeded sites formed a multi-layered canopy and were starting to be colonized by non-planted species. We sampled 90 species from the 152 seeded plus 68 colonizer species. Seeded communities present more orthodox, wind-dispersed seeds than reference forests. However, animal-dispersed and recalcitrant seed traits are found in colonizers. Canopy frequently closed (80%), forming a tall secondary forest with high height-to-diameter ratio trees that do not bifurcate in the first 3 years. Broadcast seeding sites had higher seedling and sapling densities than sites that received other restoration methods. In conclusion, direct seeding was a successful method for tropical forest restoration, promoting a structure that was more like resilient natural regeneration sites than to non-resilient natural regeneration sites and seedling planting sites.

Seed networks for upscaling native seed supply in Brazil

Brazil has committed to restore 12 million hectares of degraded lands by 2030, however, there is a shortage of native seed supply. In this research, we assess the outcomes of six Brazilian seed networks in the Amazon, Cerrado, and Atlantic Forest Biomes, and estimate the plant material demanded to achieve the national restoration goal. Seed networks have operated through non-governmental and governmental organisations that link local communities who have produced seeds with restoration markets. Overall, these initiatives have produced 386 tonnes of seeds and engaged 1,046 collectors over the last 10 years. Each collector produced on average 45.5 kg of seed per year, receiving approximately US$270 yearly as cash income, regardless of the year, network or region. We also estimated – based on 2,152 germination tests of 122 species – a germination rate of 39.9 ± 7.9%. Running a Markov Chain Monte Carlo with 10,000 rounds we found a minimum germination rate of 17.75% for the mix of 122 species. Our finds show implementing Brazil’s targets will require from 18,876 to 88,861 tonnes of seeds, and between 9,796 and 14,994 million seedlings depending on the restoration methods adopted. Although there are caveats in these estimates because of lack of knowledge about seed ecology and the complex field interactions and responses, restoration clearly requires a broader investment compared with the current structure and technology available. Although the community-based model is a potential productive arrangement, for spreading initiatives it is essential to overcome the limitations in knowledge and uncertain policies and markets.

Overcoming limiting factors to seedling establishment: Physiological, morphological, spatial, and temporal tactics

Using nursery-produced seedlings for restoration helps achieve on-site objectives by increasing the trajectory of ecosystem services compared with natural regeneration. This function, however, is only possible with quality seedlings that are matched to the objectives with the appropriate morphology, physiology, and genetics. Within the nursery culture environment, it can be possible to express seedling traits that favor establishment on outplanting sites that have a myriad of limiting factors such as depleted soil moisture and competing vegetation. Simple morphological traits that include longer root systems or greater height are logical targets in such instances. One critical aspect to quality seedling attributes that is less understood, however, is how a seedling functions—its physiology. In a sense, morphological attributes are just proxies for physiological functioning. But how do you, or how can you, condition a seedling to “function” for a specific purpose? Nursery culture has the opportunity to lay the foundational building blocks—i.e. quality—on which seedlings rely on for establishment and growth. It stands to reason, that seedling physiological conditioning can offer gains in potentially limiting outplanting conditions. Unfortunately, the direct links from nursery culture to physiology on the outplanting site are not fully realized. Our research explores the intersection of building target seedlings by varying nursery culture to match outplanting conditions with a better understanding of morpho-physiological functioning.

Maximizing seedling outplanting success with organic soil amendments

Soil organic matter (SOM) is critical for ensuring both forest soil and tree health. Although soil organic matter represents only 5% of the soil, it is critical for cation exchange capacity, water and nutrient retention, and overall site productivity.  However, increased populations and a changing climate have contributed to the loss or degradation of SOM. It is critical to understand how soil texture and the type of organic amendment may interact to alter soil processes before planting for site restoration.  Restoring organic carbon can help reverse soil productivity declines and improve plant establishment and growth. Application of organic matter to soils can supply needed plant nutrients and can improve water holding capacity to make soils more resilient to drought or flooding. Biosolids or manure additions rapidly release nutrients and can enhance plant growth in the short-term. Biochar additions, while low in nutrients, offer a stable source of soil carbon and can increase water and nutrient holding capacity. Sawdust or wood chips is another option for amending forest sites, but it is often surface applied and can decompose quickly. Organic amendments are more effective at increasing understory plant production rather than tree seedling or older tree growth, but the alteration of water holding capacity may reduce the risk of insect or disease attack.

Why nurseries are successful and why nurseries fail

The need for ecosystem restoration continues to increase, and worldwide, many ambitious initiatives, ranging in scope from local to global, are in place to contribute in response to this need. Reaching these restoration goals will require implementing a broad palette of techniques, spanning from passive to active restoration. Actively outplanting seedlings can be an important aspect of restoration, especially on the more disturbed sites. Ensuring that nurseries produce the highest-quality plant materials and that those plants become established in the field is a paramount concern. Unfortunately, all too often nurseries fail in their ability to deliver quality plants in a timely manner. The reasons for failure are numerous, but successful nurseries often share common traits, including a passion for growing plants, an understanding of the nursery’s role in the local community, an eagerness to communicate with the public as well as clients, and a management philosophy that encourages and nurtures a learning environment toward increasing plant production expertise. In particular, successful nurseries engage with their clients using the tenets of the Target Plant Concept, especially the realized need for client‒nursery sharing of expectations and results that are continually reassessed and modified based on field results. Working together, clients and nurseries are most successful when biological and societal needs are assessed and satisfied.

The critical importance of nurseries for meeting ecosystem restoration goals

Global leaders, through the Bonn Challenge, the UN Decade on Ecosystem Restoration, and other programs, have pledged to restore millions of hectares in the near future. To achieve these unprecedented and ambitious goals, millions of established plants are required. Natural regeneration and direct seeding may partially achieve that need, but have limited efficacy in areas with environmental stresses, animal damage, and seed scarcity. Thus, high-quality, nursery-grown seedlings can be critical for providing plant material needed to create healthy, functional, and resilient ecosystems. Well-managed plant nurseries also serve as a hub of local plant expertise, help ensure genetically appropriate plants are used for specific outplanting sites and support sustainable livelihoods in rural communities. In spite of their integral role, however, nurseries often receive inadequate training, resources, or long-term support. Production of insufficient plant quantities or poor-quality plants have considerable economic and environmental consequences and will result in unsuccessful planting programs. To succeed, nurseries need integrated and sustained support from a range of actively engaged stakeholders including communities, policymakers, and land managers to insure they are a priority investment to restore thriving landscapes worldwide.

International Principles and Standards for Restoration. Second Edition. A Brief Introduction to Key Concepts and Tools

Priority Effects in Restoration: Benefits, Costs, Caveats, and Questions

Direct seeding for ecological restoration in Brazil – roadmap process and the Strategic Action Plan

The direct seeding technique is an option for restoration projects that is significantly cheaper, more efficient, and reaches higher impact compared to planting seedlings, contributing to large scale restoration. Yet its adoption in Brazil is still small, due mainly to the lack of knowledge of the technique itself among researchers and practitioners. Other barriers that can discourage or prevent direct seeding adoption are the supply of seeds, diversity of implementation activities for different vegetation and physical conditions, and regulatory barriers, among others. In this context, the Seed Pathway Initiative was developed to leverage direct seeding adoption in Brazil, enabling conditions for its large-scale use through a multi-stakeholder roadmap that resulted in an Action Plan to increasing direct seeding in restoration projects. Government, researchers, NGOs, service providers, seed networks, and other relevant stakeholders contributed for a diagnostic, analysis and prioritized actions, also considering regional particularities. The Action Plan contains strategies and actions designed for each focal region of the initiative (São Paulo and Mato Grosso states), as well as those of national scope and for other specific regions, important in the country’s environmental context. The Action Plan covers a 5-year horizon, setting out the strategy for the entire country with lessons for other countries and considering the activities with the greatest impact on the technique adoption. Some of the actions are technical demonstration units for capacity purposes, outreach activities (publications of booklets and projects database), professionalization of seed networks, changes of specific regulations, and establishment of public-private partnerships.

What Do We Know & What Do We Still Need to Know to Use Priority Effects in Ecological Restoration?

Native woodland restoration to counteract carbon land emission in Iceland

Restoration has become one of the key measures to mitigate climate change. With increasing emphases not only on carbon sequestration but also carbon emission from degraded land, calls for better strategies and prioritisation are critical. Iceland with its volcanic soil (Andosol) is an example of large-scale ecosystems conversion following settlement in the 9th century that resulted in approximately 50% of the island now classified as having considerable to severe erosion. To date attempts have been made to revegetate and restore ecosystems on this badly degraded land. However, improved understanding of the degradation processes highlights the need to focus restoration activities on degraded lands that are potential carbon sources, but which have not yet crossed a threshold leading to severe soil erosion. Downy birch (Betula pubescens) is the only native woodland forming species in Iceland, and its distribution has declined from estimated 20-30% of the country at settlement to 1.5% at present. Recent examples show a rapid spread of birch where conditions are favourable, even into nutrient-poor barren landscapes. Thus, it is imperative to identify areas in which minimum interventions may initiate this process. The aim of this study is to utilise existing data with known geographic locations on birch distribution and land classes to analyse the potential for birch woodland restoration with minimum interventions. We will use Iceland as an example of how prioritisation and natural regeneration together with limited input can simultaneously combine the three UN conventions on climate change (UNFCCC), biological diversity (CBD) and desertification (UNCCD).

Prioritization Tools: A Case for the Management Unit Control Plan tool

Is the restoration of thicket in the Albany Thicket Biome with woody species really not feasible?

It has been reported that the restoration of semi-arid thicket with woody species is not ecologically feasible in South Africa. Transformed and degraded semi-arid thicket exhibits exceedingly poor resilience with normal succession precipitating low species diversity dominated by grasses and ephemerals. The transformed and degraded mesic-thicket types have only slightly improved resilience but also limited species richness with many guilds missing – despite many decades without the drivers of degradation being present. The restoration of thicket has largely been focused on the en masse planting of one species (Portulacaria afra) with the assumption that, once established, it will facilitate the natural return of the other species, specifically the missing woody plant guild.  A lack of understanding regarding the ecophysiology of key woody species, as well as the nuances of the microclimate needed for succession has limited restoration success in the thicket. This research seeks to take a systems approach to understanding the multi-scale dynamics for the restoration of mesic-thickets, then apply the wisdom gained from this process to tackling the major challenge of effective restoration of degraded thicket areas with woody species.  The results from fifteen common woody species found in mesic thickets indicates that drought-sensitivity, germination success, seedling growth rate, herbivory, nurse-planting, tree-shelters, ponding, and other treatments have significant species-specific effects. The intimate understanding of these relationships correlated spatially and temporally with the major thresholds that limit the germination, establishment, survival, growth rate, and canopy recruitment – will enable the successful restoration of thicket with woody species.

The Koup, the gold standard in community base natural resource management in Western Cape, South Africa

The implications of a “project” mindset on ecological restoration at the community level – Mpophomeni township as a case study

The Mpophomeni enviro-champs are lauded as a best practice model for a community-based approach to catchment management and restoration. Vital work to help “Save Midmar Dam” has been undertaken by a handful of community members for several years, and they were recently mentioned in the Presidential Jobs Summit Framework Agreement. However, when one scratches under the surface, the tale of the Enviro-champs and their essential work is one of two steps forward, and one step back. Funding has been from several sources, over various time frames, with disparate objectives, resulting in loss of momentum, and at times disillusionment. The Mpophomeni Enviro-champs are just one example of how short-term funding cycles impact negatively on effective, sustainable ecological restoration at a community level. The approach to community-based ecological restoration needs to shift to long-term programming that is built into the “operations” of responsible authorities. The business case for this approach is clear, with the annual operating cost of maintaining community teams much lower than the cost of refurbishment, rehabilitation and/or replacement due to the lack of daily maintenance of our ecosystems. The benefit to the natural environment is only one of the impacts; the social impact within the broader community being equally important. With a long-term funding mindset, ecological restoration moves from the simple tasks of clearing, cleaning, and monitoring, to broader education and social change of an entire community and its relationship to the natural environment. Surely this should be our goal.

Undervalued and Overlooked: Naturally Regenerated Vegetation in Agroecological Landscapes

Restoring habitat and hope: The Sagebrush in Prisons Project

The Sagebrush in Prisons Project, a collaborative effort between the US Department of Interior Bureau of Land Management, Institute for Applied Ecology, and state Departments of Correction engages multiple prisons across seven western states (CA, ID, MT, NV, OR, WA, UT) in the United States. Working with prison systems to engage inmates in habitat conservation and ecological science is an innovative approach to increase our ability to reestablish habitat and at-risk species, while simultaneously providing people in custody with opportunities for reciprocal restoration, vocational education, therapeutic activities, safer conditions, and lower costs of imprisonment. Adults in custody contribute to the conservation of Greater Sage-Grouse and its habitat, the Sagebrush Sea, by growing sagebrush plants in prison-run native plant nurseries. This distributed network of nurseries produces locally sourced sagebrush seedlings for habitat restoration on public lands, primarily in response to wildfires in priority habitat for the grouse. The quality of these sagebrush seedlings is exceptional, and first year survival is very high (>80%). Since 2014, the program has engaged over 3,500 adult and youth inmates who grew and planted over 1.1 million sagebrush seedlings. Adults in custody also receive training in horticulture and nursery production, lectures in science and conservation, and certificates for their accomplishments. Including incarcerated people in conservation and science taps into the positive potential of over 2 million inmates at over 4,000 prisons and jails in the United States and creates new partnerships for educating an underserved community and supporting large scale ecological restoration and research. 

Rural Community Socio-ecological Benefits in the Upper Pongola Catchment

DroneSeed: Using UAVs to conduct surveys, herbicide applications, and aerial seed deployment in forests and rangelands

DroneSeed is a Seattle-based startup that is developing software, hardware, and infrastructure for operational capacity of Unmanned Aerial Vehicles (UAVs) to conduct surveying, herbicide application, and aerial seed deployment in forests and rangelands. Their mission is to provide more efficient and rapidly scalable survey and revegetation services for myriad ecosystem management needs. They are currently paid per acre to survey, mitigate invasive species with herbicides, and plant (enabled seed) for the largest timber companies in the US. They are also partnered with The Nature Conservancy and have begun seed-based rangeland restoration work in Oregon and post-fire forest restoration work in other locations in the American West. The presentation will provide an overview of the company’s technology, review projects and milestones, and outline the research and development supporting their data-driven approach. Wildfire and other large-scale ecosystem disturbances are increasing in frequency and severity. Constraints to post-disturbance revegetation include accessibility to remote areas, difficulty distributing seed precisely at scale, invasive species mitigation, and associated costs. DroneSeed is developing a multi-pronged approach to revegetation using UAVs that is applicable to large-scale post-disturbance revegetation and native plant management at an effective cost. Their supervised classification platform is the basis for a machine learning software being developed for seed placement (i.e. micrositing) for optimizing germination and survival. DroneSeed is increasing operational capacity using swarm technology, enabling multiple heavy lift aircraft to move material payloads across restoration areas with increased precision. The company is precedent setting in the regulatory environment allowing for this work.

Stewardship: taking care of something, e.g. valuable objects

Secondary invasion after clearing invasive Acacia saligna in the South African fynbos

It is often assumed that clearing invasive alien species will lead to the dissipation of their negative impacts and recovery of native biodiversity. However, this is often not the case because clearing of primary invasive alien species can lead to secondary invasion by non-target species. We investigated the effects of vegetation type and application of fire during management of biomass after clearing invasive acacias on secondary invasion in the South African fynbos. Furthermore, we determined how these effects change with years after clearing. We sampled vegetation in lowland and mountain fynbos cleared of Acacia saligna using the “fell, stack and burn” method. During burning of the stacked slash, the area at the centre of the stack experiences a high severity fire while the area at the edge experiences a low severity fire. After fire, burn scars remain in place of the stacked slash. We sampled in and outside of 80 burn scars over three years after clearing. We identified 32 secondary invader species. Secondary invader cover was lower where there were no fires compared to where there were high severity fires (27%) and low severity fires (30%). Three years after clearing, secondary invader richness and cover remained similar to or higher than in the first year, while secondary invader richness was similar between lowland and mountain fynbos. We conclude that practicing restoration ecologists have to manage these species to ensure successful restoration of native biodiversity.

Ex-situ Plant Conservation in Eastern Madagascar: Creating a Resource for Future Forest Restoration Endeavours