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Several attempts to eradicate invasive alien species have been initiated in South Africa and despite no formal eradication declaration, several species have been brought down to low levels or are now absent from the country. Based on an expert workshop with South African implementing agencies on best nationwide eradication practices, we recommend that eradication programmes should be well coordinated, and characterised by collaboration between implementing agencies, researchers and practitioners. Countries should have a list of eradication targets informed by the best available science, with targets ranked according to priority. The best eradication model should be used consistently until eradication is achieved. While most of these priority areas are not novel, it does provide a perspective from a biodiverse African country with limited funding, based on 16 years of experience in implementing eradication programmes. It corroborates challenges experienced elsewhere in the world and contributes to enhancing eradication outcomes globally. [ABSTRACT FROM AUTHOR]

Forest canopies provide important resources for insect communities via flowers. Yet, pollination systems of tall forest trees are poorly studied, resulting from the difficulties in observing pollinator activity at the canopy level and great temporal variation in flower production. In temperate forest canopies of the southern hemisphere, small, whitish and generalist flowers seem to dominate. Here, we observed insect flower visitors, at the canopy level, to four southern Afrotemperate forest tree species bearing small, white to green flowers in a large, indigenous forest. Additionally, we quantified flower traits and collected pollen from representative insect visitors. A total of 105 insect species, from 48 families and 7 orders, were observed visiting flowers. In terms of total flower visits, the generalist Cape honey bee (Apis mellifera capensis) made up ca. 57% of all flower visits. A third of the total observation time covered crepuscular to nocturnal flower visits; yet only 12.68% of total visits took place during this time. Interestingly, despite both trees and insects being largely generalist in their interactions with one another (supported by the presence of conspecific and heterospecific pollen on most flower visitors), some insect species showed strong preferences for specific species of tree, driving dissimilar, interspecific assemblages of flower visitors. The pollinator community disparity may be explained through the unique and dissimilar floral traits for each tree species, both in flower size and in petal reflectance. We conclude that within generalist pollination systems, distinct and non‐random mutualisms can develop between different species of plants and a diverse suite of pollinators, and that floral traits could partially predict such interactions. [ABSTRACT FROM AUTHOR]

The successful restoration of endangered habitat types at a low cost is of vital importance. We tested how successful and cost‐effective six combinations of restoration treatments were in the Cape Floristic Region of South Africa. Treatments were applied to an area that was primarily covered invasive alien grasses. Treatments that tested combinations of burning, direct sowing of seed, and planting of seedlings, aimed to test the synergistic effect of three treatment factors. Topsoil translocation aimed to determine if this, combined with planting, can restore native shrub cover and whether the addition of mulch and seed can improve overall success. The mechanical removal of invasive grasses, sowing and planting, were tested in the absence of fire. Both topsoil translocation treatments and the treatment that had been burned, sown and planted ("Burn‐sow‐plant") led to plant species richness resembling near‐pristine plots and approximately 30% higher than the burn‐only treatment ("Burn"). Native shrub cover was the highest for treatments which included planting. Survival for planted species was 36–41% higher for Burn‐sow‐plant. The contribution of sowing was low, with 9–16% of species sowed being present across treatments. We show that topsoil translocation can be successful if combined with planting. Burn‐sow‐plant was most successful at a reasonable cost, despite planting being expensive, whereas Burn and Burn‐sow were less successful, but cheaper. The treatment in which grass was removed before sowing and planting was the least successful and most expensive. We conclude that the most successful treatments are not necessarily the most expensive. [ABSTRACT FROM AUTHOR]

Fire‐adapted species invading fire‐prone ecosystems in Mediterranean climate regions are difficult to control because they are equally responsive to restoration treatments. We assessed the efficacy of delaying a prescribed burn to promote the recruitment of native species in a Lowland Sand Fynbos ecosystem invaded by alien Acacia saligna. Acacia stands were felled and fallowed for 2 years before burning the slash and sowing pre‐treated fynbos seeds. We hypothesized that sowing pre‐treated fynbos seeds after fallowing cleared areas before burning would improve the regeneration of native species. Fallowing cleared areas would reduce the density of acacia seeds and post‐fire acacia recruitment while allowing felled acacia biomass to dry and decay over time leading to improved prescribed burn properties. Sowing pre‐treated fynbos seeds improved the recovery of native cover but had little effect on the recovery of native species diversity after 2 years. Although the rapid recruitment of annual native species did not affect acacia density, it might have contributed to reduced post‐fire acacia cover and allowed the native perennial species to establish. After 2 years of fallowing cleared areas, the density of acacia seeds and post‐fire acacia recruitment was reduced by ≈50% and 80% respectively. Although too dense to be outcompeted by recruited native species alone, this reduced acacia recruitment helped to decrease and delay the need for follow‐up acacia clearing as it was where burning occurred soon after felling acacia stands. The recruited native species managed to establish before the acacia emergents were removed unlike where burning occurs soon after felling and where native species were outcompeted resulting in the need for follow‐up sowing. In conclusion, building resilience against acacia resurgence by increasing the pool of sown species to recover a good cover of native species in combination with the timely removal of acacia recruits can help to scale up restoration. [ABSTRACT FROM AUTHOR]

Invasive alien plants (IAPs) pose a serious threat to biodiversity, agriculture, health, and economies globally. Accurate mapping of IAPs is crucial for their management, to mitigate their impacts and prevent further spread where possible. Remote sensing has become a valuable tool in detecting IAPs, especially with freely available data such as Sentinel-2 satellite imagery. Yet, remote sensing methods to map herbaceous IAPs, which tend to be more difficult to detect, particularly in shrubland Mediterranean-type ecosystems, are still limited. There is a growing need to detect herbaceous IAPs at a large scale for monitoring and management; however, for countries or organizations with limited budgets, this is often not feasible. To address this, we aimed to develop a classification methodology based on optical satellite data to map herbaceous IAP's using Echium plantagineum as a case study in the Fynbos Biome of South Africa. We investigate the use of freely available Sentinel-2 data, use the robust non-parametric classifier Random Forest, and identify the most important variables in the classification, all within the cloud-based platform, Google Earth Engine. Findings reveal the importance of the shortwave infrared and red-edge parts of the spectrum and the importance of including vegetation indices in the classification for discriminating E. plantagineum. Here, we demonstrate the potential of Sentinel-2 data, the Random Forest classifier, and Google Earth Engine for mapping herbaceous IAPs in Mediterranean ecosystems. [ABSTRACT FROM AUTHOR]

To support and scale up global restoration efforts, the United Nations (UN) has proclaimed 2021–2030 the "UN Decade on Ecosystem Restoration." The Decade offers significant opportunities for and challenges to restoration, in particular for Africa, a continent that has a large need and potential for restoration. We thus argue that the Decade must be a success in and for Africa, and for this to happen, opportunities and challenges to achieving its goals must be promptly identified, and considered in the planning and implementation of restoration. Here, we outline six key areas that should be considered at a strategic level by African countries during the Decade. These are: (1) ensuring effective oversight and governance relevant to Africa; (2) translating the goals to meet the African context; (3) making the case for restoration amid multiple development demands; (4) growing an African restoration community of practice based on regional need; (5) collaborating to improve restoration outcomes; and (6) establishing an Africa‐relevant evidence base for restoration. We believe that these six key areas—even though they are not all novel—are currently not addressed at a level that matches the scale of the problem on the continent. Although the specific actions to be taken under each key area are dependent on the restoration context, integrating these key areas in the planning and implementation of restoration efforts will likely lead to improved restoration outcomes during the Decade. [ABSTRACT FROM AUTHOR]

The method of clearing alien species and the nature of the soil seedbank influence the quality of restoration outcomes, particularly in fire‐prone ecosystems heavily invaded with fire‐adapted alien species. One of the challenges encountered is reducing the likelihood of reinvasions when the invading species are equally responsive to restoration treatments. By simulating the fire effects that are required to regenerate native vegetation, the study tested whether the recovery of the native species could be initiated without conducting a prescribed ecological burn. In a case study of South African Cape Flats Sand Fynbos with a heavy invasion of Acacia saligna, the felled acacia were stacked into brush piles, with the litter raked off from the sowing areas and the collected seeds were pre‐treated for germination. Despite the lack of a fire, the sowing of pre‐treated seeds on raked plots led to good recovery of native vegetation over time. This was indicated by the recovery of higher density, cover and richness of native species in sown plots compared with unsown treatments. However, the recovery of native species had not approached the vegetation structure comparable to a reference site after 2 years; that is, only partial fynbos structure was recovered. The recruitment of acacia was less dense without fire, as hypothesised, and independent of treatment. However, over time, control plots had higher acacia cover than other treatments. Despite this sparse recruitment of acacia, the acacia seedbank decreased naturally to about 50% of the initial size over 2 years in control plots. Raking off litter during site preparation removed 50% of the acacia seedbank which decreased slightly thereafter. Consequently, the residual acacia seedbank was relatively similar across treatments after 2 and a half years. In conclusion, circumventing prescribed burns in heavily degraded fynbos ecosystems is a scalable restoration strategy, as recruitment of alien acacia was minimized, its seedbank declined significantly, and good native cover developed after clearing and sowing. [ABSTRACT FROM AUTHOR]