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A horizon scan was conducted to identify emerging and intensifying issues for biodiversity conservation in South Africa over the next 5-10 years. South African biodiversity experts submitted 63 issues of which ten were identified as priorities using the Delphi method. These priority issues were then plotted along axes of social agreement and scientific certainty, to ascertain whether issues might be "simple" (amenable to solutions from science alone), "complicated" (socially agreed upon but technically complicated), "complex" (scientifically challenging and significant levels of social disagreement) or "chaotic" (high social disagreement and highly scientifically challenging). Only three of the issues were likely to be resolved by improved science alone, while the remainder require engagement with social, economic and political factors. Fortunately, none of the issues were considered chaotic. Nevertheless, strategic communication, education and engagement with the populace and policy makers were considered vital for addressing emerging issues.

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.

Societal Impact Statement: Debates about the impacts of human settlement on Madagascar's habitat have missed the Malagasy perspective. Using indigenous and local knowledge in the form of toponyms, we find many regions across today's treeless grasslands are named after forest/trees, suggesting they may be novel. Where observed habitat does not match toponyms, erosion is significantly more likely at landscape scales. This suggests rapid expansion of erosion following human removal and burning of endemic forest, savanna woodland, heathland and grass assemblages. Findings also provide a timely warning: current practices may be unsustainable and may impact not only biodiversity but also human wellbeing unless urgently addressed. Summary: The debate surrounding the extent of Madagascar's treeless grasslands at human settlement is important because introduced disturbance can negatively impact the biodiversity and productivity of systems that evolved under different regimes. Indigenous and local knowledge (ILK), often overlooked, can provide information about past vegetation structure. To test whether clearance of forest and trees, frequent fires and pasture preparation have accelerated today's island‐wide erosion, we use vegetation toponyms and assess whether mismatches between these and current vegetation types are significantly more likely to be associated with erosion.Using Malagasy and Imerina linguistic records spanning 150 years, we mapped forest‐related and grassland‐related extensive toponyms in current grassland and forest, respectively. We then assessed whether remotely‐sensed erosion was more likely when toponyms and current habitat did not match.We found 316 sites in treeless grasslands, named after forest/clusters of trees, but no grassland‐named sites in forest. Globally, natural forest and grasslands both constrain erosion. Forest toponyms in grassland were significantly more likely to reflect erosion than sites in extant forest.These findings concur with palaeoecological, geomorphological, molecular and rangeland palatability studies. Malagasy ILK, hitherto largely ignored as a source of information, strongly suggests vegetation clearance and human disturbance have exacerbated the degradation of terrestrial, freshwater and marine ecosystems through topsoil loss and siltation and selected fire‐adapted, less‐palatable grasslands. Malagasy ILK in the form of toponyms highlights the need to address the negative impacts of burning and land‐clearance practices (e.g., loss of biodiversity and ecological function, decreased agricultural productivity, collapsed fisheries), given island‐wide challenges to food security and conservation. [ABSTRACT FROM AUTHOR]

Background. Pollinators, which provide the agriculturally and ecologically essential service of pollination, are under threat at a global scale. Habitat loss and homogenisation, pesticides, parasites and pathogens, invasive species, and climate change have been identified as past and current threats to pollinators. Actions to mitigate these threats, e.g., agri-environment schemes and pesticide-use moratoriums, exist, but have largely been applied post-hoc. However, future sustainability of pollinators and the service they provide requires anticipation of potential threats and opportunities before they occur, enabling timely implementation of policy and practice to prevent, rather than mitigate, further pollinator declines. Methods.Using a horizon scanning approach we identified issues that are likely to impact pollinators, either positively or negatively, over the coming three decades. Results.Our analysis highlights six high priority, and nine secondary issues. High priorities are: (1) corporate control of global agriculture, (2) novel systemic pesticides, (3) novel RNA viruses, (4) the development of new managed pollinators, (5) more frequent heatwaves and drought under climate change, and (6) the potential positive impact of reduced chemical use on pollinators in non-agricultural settings. Discussion. While current pollinator management approaches are largely driven by mitigating past impacts, we present opportunities for pre-emptive practice, legislation, and policy to sustainably manage pollinators for future generations.

A characteristic feature of Earth's drylands is the patchy nature of the vegetation, often referred to as a two‐phase mosaic landscape, comprised of a homogenous matrix containing distinctive vegetated patches. The latter are considered vital for ecosystem functioning as they provide refuge to biota from unsuitable conditions. Ground‐living (epigeic) and foliage arthropods contribute to dryland biodiversity patterns and processes, but little is known of how their richness, abundance, and composition varies between patches and the matrix in these systems. Throughout the Succulent Karoo, South Africa, such patches (earthen mounds referred to as heuweltjies) are hotspots for both floral and faunal diversity. We investigate how epigeic and foliage‐dwelling arthropod species richness, abundance, and community composition respond to heuweltjie patch characteristics, particularly isolation (distance to nearest neighbor, average distance to nearest neighbor, patch density), size (area), and quality (average plant height, dead plant cover, leaf litter cover, termite frass) during a severe drought. Patch isolation and quality were significantly correlated with arthropod richness, abundance, and community composition. More specifically, average proximity of sampled heuweltjies to other neighboring heuweltjies, termite frass, and vegetation structure (height, leaf litter and dead plant cover) were key determinants for epigeic and foliage‐dwelling arthropods' species richness, abundance, and community composition. The uniqueness of these mounds as landscape features increases niche and microhabitat availability for arthropods. This emphasizes their importance as promoters of landscape heterogeneity and highlight heuweltjies as key to the spatial distribution of arthropod assemblages in the Succulent Karoo. [ABSTRACT FROM AUTHOR]

The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.

Societal Impact Statement: The relationship between rainfall, fire and habitat can display incongruencies. The 2021 Malagasy Grassy Biomes Workshop identified understanding fire regimes as a knowledge gap. This study pinpoints regions where anthropogenic fire has the potential to transform or has transformed habitat to treeless‐grassland, by identifying landscape‐scale, island‐wide fire anomalies across half of Madagascar. Its eastern forests burn like savannas, and central‐western grasslands burn frequently and intensely despite receiving rainfall usually associated with forest and fire‐absence. Recognising the incongruity and better understanding its drivers can mitigate against landscape‐scale degradation, improving ecological function, and human well‐being. Summary: Data show that since 1953, human‐lit fires on Madagascar have transformed clear‐cut forest to treeless‐grasslands. To address the extent of Malagasy treeless‐grasslands at human settlement, the 2021 Malagasy Grassy Biomes Workshop identified the role of fire as a critical knowledge‐gap for understanding ecological function. The relationship between mean annual precipitation (MAP), fire and habitat is well established across mesic systems. Anthropogenically transformed habitats often deviate from expected ecological patterns, so we tested for landscape‐scale, island‐wide MAP‐related fire and habitat anomalies.We collated Malagasy fire, habitat and MAP datasets, identifying location and scale of incongruities relative to global fire‐habitat‐MAP expectations. Next, we tested for mismatches in fire regimes (frequency, timing, extent and intensity of fires) between Malagasy and equivalent global biomes, using global, comprehensive landscape‐scale fire regime data.Across half of Madagascar, fire frequency and habitat are decoupled from MAP, and fire regimes across Malagasy ecoregions differ significantly from those in shared biomes elsewhere in the world. Landscape‐scale incongruities span Malagasy eastern forests (which burn like savanna systems) and central‐western treeless‐grasslands, which burn frequently and intensely despite receiving MAP typical of forest presence and fire‐absence, globally.Fire‐MAP incongruities identify potentially transformed areas, or those undergoing transformation by fire, and establish a platform for investigating the nuanced social, political and ecological dynamics that may contribute to and perpetuate these anomalies. Incongruities also highlight the anthropogenic landscape degradation associated with fire anomalies. Addressing these impacts can facilitate restoration of ecological function, productivity and food security, benefiting biodiversity and humans at multiple scales. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: The 26th United Nations Climate Change Conference emphasised the need to modify practices that negatively impact biodiversity and food security in the context of global change. Following Madagascar's drought‐induced famine, our systematic review supports the theory that grasslands of the Malagasy Central Highland that are subjected to human‐lit fires are anthropogenically derived. Furthermore, these overly frequent fires that characterise much of the Malagasy Central Highland grasslands select poorly palatable grasses. Given the reliance on pastoralism as insurance against crop failure in Madagascar, fire‐dependent practices that degrade rangeland emerge as a threat to food security and biodiversity. Education can mitigate against future humanitarian crises. Summary: Food insecurity is greatest in countries where impacts of global change are predicted to be severe. Many, like Madagascar, rely on livestock‐based pastoralism (and consequently palatable rangelands) for insurance against natural disasters and crop failure. It is recognised that derived grasslands can impact climate and biodiversity. Furthermore, the well‐established palatability‐flammability trade‐off predicts that overly‐frequent fires select increasingly unpalatable, fire‐adapted grassland. The drought‐induced Malagasy famine of 2021 highlights the need to identify factors that threaten food security. Given the ubiquitous practice of rangeland preparation through annual, landscape‐scale human‐lit fires, we evaluate whether Malagasy grasslands are derived and then test for fire‐driven selection of increasingly degraded and unpalatable rangelands across Madagascar's largest grassland system, the Malagasy Central Highland (MCH). We conducted a systematic literature review, evaluating for a palatability‐flammability trade‐off, by determining dominant Malagasy grass species, and then applying functional traits, and palatability ratings to these species. Data were extracted using a suite of relevant search terms, and of 1977 studies identified, 145 were directly relevant to the questions posed. Evidence from the review is compelling for much of the Malagasy highland grassland being derived. Furthermore, Malagasy dominant grass species are fire‐adapted with poor forage‐value, suggesting current burning practices negatively impact both biodiversity and pastoralism. Decreasing rangeland palatability caused by human‐lit fires in a society suffering food insecurity emphasises the need to re‐evaluate pastoralist burning practices. Identifying optimal fire frequencies can avert breaching fire‐induced tipping points to rangeland palatability and the humanitarian crises that may follow. [ABSTRACT FROM AUTHOR]