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Multiple anthropogenic challenges threaten nature's contributions to human well-being. Agricultural expansion and conventional intensification are degrading biodiversity and ecosystem functions, thereby undermining the natural foundations on which agriculture is itself built. Averting the worst effects of global environmental change and assuring ecosystem benefits, requires a transformation of agriculture. Alternative agricultural systems to conventional intensification exist, ranging from adjustments to efficiency (e.g. sustainable intensification) to a redesign (e.g. ecological intensification, climate-smart agriculture) of the farm management system. These alternatives vary in their reliance on nature or technology, the level of systemic change required to operate, and impacts on biodiversity, landscapes and agricultural production. Different socio-economic, ecological and political settings mean there is no universal solution, instead there are a suite of interoperable practices that can be adapted to different contexts to maximise efficiency, sustainability and resilience. Social, economic, technological and demographic issues will influence the form of sustainable agriculture and effects on landscapes and biodiversity. These include: (1) the socio-technical-ecological architecture of agricultural and food systems and trends such as urbanisation in affecting the mode of production, diets, lifestyles and attitudes; (2) emerging technologies, such as gene editing, synthetic biology and 3D bioprinting of meat; and (3) the scale or state of the existing farm system, especially pertinent for smallholder agriculture. Agricultural transformation will require multifunctional landscape planning with cross-sectoral and participatory management to avoid unintended consequences and ultimately depends on people's capacity to accept new ways of operating in response to the current environmental crisis. [ABSTRACT FROM AUTHOR]

Parasitoids are a significant mortality factor in the population dynamics of many arthropods involved in key ecological processes such as herbivore-plant and predator-prey interactions. Parasitoids are therefore widely used in biocontrol programs. Global change phenomena influence these natural and anthropocentric roles of parasitoids and here we review the effects of the main drivers and their interplay. Land use intensification modifies landscape structure and elevates agroecosystem loads of fertilisers and pesticides creating risks for parasitism and loss of biocontrol services. Climate change can affect parasitoids directly, affecting physiology and survival, or indirectly via phenological and other effects (plant chemistry, herbivore-induced plant volatiles HIPVs) on their hosts, endosymbionts and plants. Biological invasions have the potential to modify native host-parasitoid systems and elevate risk of novel pest dynamics, requiring restoration of biocontrol. The interplay between these global change drivers may thus exacerbate the overall risk to parasitism in future agricultural landscapes. To make more accurate predictions, future studies could focus on the impact of interacting global change drivers on parasitoids and the biocontrol services they provide. Moreover, host and parasitoid specificity appear to be a key driver in assessing the effects of global change on parasitoids. [ABSTRACT FROM AUTHOR]

Transformative changes in agriculture at multiple scales are needed to ensure sustainability, i.e. achieving food security while fostering social justice and environmental integrity. These transformations go beyond technological fixes and require fundamental changes in cognitive, relational, structural and functional aspects of agricultural systems. However, research on agricultural transformations fails to engage deeply with underlying social aspects such as differing perceptions of sustainability, uncertainties and ambiguities, politics of knowledge, power imbalances and deficits in democracy. In this paper, we suggest that conflict is one manifestation of such underlying social aspects. We present an original conceptualization and analytical framework, wherein conflict is recognized as an important motor for redistribution of power and leverage for social learning that--if addressed through a conflict transformation process--could potentially create a step-change in agricultural transformation towards greater sustainability. Our analysis, building on an extensive literature review and empirical case studies from around the world, suggests a novel approach to guide future transdisciplinary research that can support agricultural transformations towards sustainability. [ABSTRACT FROM AUTHOR]

Increasing honey demand and global coverage of pollinator-dependent crops within the context of global pollinator declines have accelerated international trade in managed bees. Bee introductions into agricultural landscapes outside their native ranges have triggered noteworthy invasions, especially of the African honey bee in the Americas and the European bumble bee Bombus terrestris in southern South America, New Zealand, Tasmania, and Japan. Such invasions have displaced native bees via competition, pathogen transmission, and invaders' capacity to exploit anthropogenic landscapes. At high abundance, invasive bees can degrade the mutualistic nature of many of the flower-pollinator interactions they usurp, either directly by affecting flower performance or indirectly by reducing the pollination effectiveness of other flower visitors, with negative consequences for crop pollination and yield. We illustrate such effects with empirical examples, focusing particularly on interactions in the Americas between B. terrestris and raspberry and between the African honey bee and coffee. Despite high bee abundance and flower visitation in crops, theoretical and empirical evidence suggests that agricultural landscapes of pollinator-dependent crops dominated by invasive bees will be less productive than landscapes with more diverse pollinator assemblages. Safeguarding future crop yield and aiding the transition to more sustainable agricultural landscapes and practices require we address this impact of invasive bees. Actions include tighter regulation of the trade in bees to discourage further invasions, reducing invasive bee densities and dominance, and active enhancement of ecological infrastructure from field to landscape scales to promote wild bee abundance and diversity for sustained delivery of crop pollination services. [ABSTRACT FROM AUTHOR]

Insect pollination constitutes an ecosystem service of global importance, providing significant economic and aesthetic benefits as well as cultural value to human society, alongside vital ecological processes in terrestrial ecosystems. It is therefore important to understand how insect pollinator populations and communities respond to rapidly changing environments if we are to maintain healthy and effective pollinator services. This chapter considers the importance of conserving pollinator diversity to maintain a suite of functional traits and provide a diverse set of pollinator services. We explore how we can better understand and mitigate the factors that threaten insect pollinator richness, placing our discussion within the context of populations in predominantly agricultural landscapes in addition to urban environments. We highlight a selection of important evidence gaps, with a number of complementary research steps that can be taken to better understand: (i) the stability of pollinator communities in different landscapes in order to provide diverse pollinator services; (ii) how we can study the drivers of population change to mitigate the effects and support stable sources of pollinator services and (iii) how we can manage habitats in complex landscapes to support insect pollinators and provide sustainable pollinator services for the future. We advocate a collaborative effort to gain higher quality abundance data to understand the stability of pollinator populations and predict future trends. In addition, for effective mitigation strategies to be adopted, researchers need to conduct rigorous field testing of outcomes under different landscape settings, acknowledge the needs of end-users when developing research proposals and consider effective methods of knowledge transfer to ensure effective uptake of actions. [ABSTRACT FROM AUTHOR]