Wild fauna occur in every agroecosystem and their interactions with crops can influence yields positively or negatively. Research on the impact of fauna activity on agricultural production focuses mostly on either the costs (e.g. crop damage) or benefits (e.g. pollination) of this activity, with few studies addressing cost-benefit trade-offs in the same context. This has resulted in an incomplete understanding of the implications of fauna activity in agroecosystems. Through a systematic review of the literature, we connect disparate studies to promote a more holistic approach to research on wild fauna in agriculture. We identified 281 studies that quantified a cost and/or benefit of fauna activity in crop systems. Overall, 53.0 % of studies examined the costs of insect and/or bird activity, 37.7 % of studies examined benefits and just 9.3 % of studies covered both costs and benefits of insect and/or bird activity simultaneously. Most birds studied were omnivorous (44.8 %), granivorous (29.0 %) or insectivorous (16.6 %), while insect studies focused on pollinators (42.2 %) or borers (17.5 %). There were clear geographic patterns for studies, with a bias towards studies of the costs of bird activity in North America and studies of benefits in Central America/Caribbean. Most studies on benefits occurred in perennial crops and most cost studies in annual crops. Our results highlight the disjointed nature of research into the cost–benefit trade-offs of fauna activity, and it is essential that future studies examine these trade-offs in order to develop sustainable agricultural strategies that limit production losses while maximising the delivery of ecosystem services from fauna.

Scavenging birds can provide ecosystem services to pastoralists by contributing to the breakdown of animal carcasses that can harbour and spread disease. However, these benefits have yet to be quantified in Australia. We monitored rabbit carcasses using motion-sensor cameras to identify beneficial avian scavengers across four landscape types (forest, riparian, fields with large isolated trees, and open fields) on a pastoral property in north-central Victoria. We quantified the ecosystem service of carcass breakdown by measuring the per cent weight loss of carcasses exposed to scavenging birds compared to carcasses excluded from birds. Seven of the twenty-four bird-accessible carcasses were attacked by raptors in 2014, and three in 2015. When a raptor attacked a carcass, there was a significantly higher median per cent weight loss of the carcass (16.67%, interquartile range (IQR) = 8.33-100.0) compared with sites where no bird attacks occurred (6.65%, IQR = 3.03-12.06). Our results indicate that raptors are major contributors to carcass breakdown in grazing landscapes and may potentially contribute to reducing the spread of diseases such as blowfly strike and leptospirosis. Maintaining key habitat features for these species (e.g. large isolated trees) is essential for raptor conservation and maximising the ecosystem services they provide.

1 Homogeneous tree crop plantations can adversely impact wild pollinator communities by limiting the temporal continuity of food and the availability of nesting sites. Identifying how structural differences between plantations and natural vegetation influence pollinator communities is necessary for ecological management of agroecosystems. 2 Communities of potential wild pollinators (native bees, wasps, flies) were compared between monoculture almond plantations and native vegetation in a semi-arid region of southern Australia, before, during and after the late winter almond flowering period. Abundance and richness of each insect group were related to site heterogeneity and keystone structural resources at each site, focusing on food and nesting resources. 3 Relationships with site heterogeneity varied between taxa and across months. Native bee abundance and richness were strongly associated with specific keystone resources, despite showing no association with site heterogeneity. 4 The present study highlights the value of focusing on biologically meaningful resources when investigating relationships between insects and habitat, rather than on generalized heterogeneity metrics. The results suggest that maintaining keystone resources in agroecosystems can support the conservation of insects and ecosystem services, especially in areas where homogeneous agricultural systems overlap dynamic natural ecosystems.

Wild pollinators are becoming more valuable to global agriculture as the commercial honeybee industry is increasingly affected by disease and other stressors. Perennial tree crops are particularly reliant on insect pollination, and are often pollen limited. Research on how different tree crop production systems influence the richness and abundance of wild pollinators is, however, limited. We investigated, for the first time, the richness and abundance of potential wild pollinators in commercial temperate almond orchards in Australia, and compared them to potential pollinator communities in proximate native vegetation. We quantified ground cover variables at each site and assessed the value of ground cover on the richness and abundance of potential wild pollinators in commercial almond systems focussing on three common taxa: bees, wasps and flies. More insects were caught in orchards with living ground cover than in native vegetation or orchards without ground cover, although overall species richness was highest in native vegetation. Percent ground cover was positively associated with wasp richness and abundance, and native bee richness, but flies showed no association with ground cover. The strongest positive relationship was between native bee abundance and the richness of ground cover plants. Our results suggest that maintaining living ground cover within commercial almond orchards could provide habitat and resources for potential wild pollinators, particularly native bees. These insects have the potential to provide a valuable ecosystem service to pollinator-dependent crops such as almond.

Agricultural landscape elements, such as field edges, are not always a barrier to insects but can influence their distribution and dispersal behaviour. The present study investigated spatial and temporal patterns in wild pollinator (fly, wasp and non-Apis bee) distribution across an edge between natural mallee woodland and monoculture almond plantations in southern Australia, during the critical almond flowering period. This is the first study of variation in pollinator community distribution on both sides of an edge between natural vegetation and flowering tree crop plantations. Species richness, diversity and evenness (SHE) analysis was also used to identify changes in pollinator community structure relative to the edge. It is shown that the spatial distribution and structure of pollinator communities can vary across a habitat edge with an abrupt temporal changes in resources. Our results suggest that the plantation edge did not prevent wild pollinators spilling over from woodlands, although vegetation homogeneity and phenological changes in resources most likely influenced the dispersal of pollinators into plantation interiors. The findings of the present study contribute to our knowledge of edge responses by insects in managed landscapes and could motivate growers to adopt ecological management practices in commercial plantations. Future studies of insects near farmland edges should include samples on both sides of the edge and should also consider the landscape context.

1 Local and landscape factors interact to influence animal populations and, ultimately, crop yields in agroecosystems. Yet few studies have considered interactions and trade-offs between these factors within a single agroecosystem. 2 We sampled insect communities (fruit-damaging pests and Diptera and Hymenoptera pollinator and natural enemy taxa) associated with focal apple trees in south-eastern Australian orchards across a single growing season.We also measured marketable fruit yields on netted (preventing access to vertebrates) and open branches on each focal tree. We focused on relationships with local (ground cover attributes) and landscape (proximity to natural woodland) factors. 3 Importantly, we found that local flower richness in orchard understoreys may buffer the negative effects that isolation from natural woodland has on wild bee and natural enemy communities and the ecosystem services they provide. 4 The results of the present study suggest that floral diversity may be more effective in supporting beneficial insects in crop interiors, rather than at edges near natural vegetation. 5 More studies are needed that identify how local and landscape vegetation structure interact to influence communities of pest and beneficial taxa, and relevant ecosystem functions, in agroecosystems.

Ongoing debate over the ecosystem services (ES) concept highlights a range of contrasting views and misconceptions. Schröter et al. (2014) summarize seven recurring arguments against the ES concept, which broadly relate to ethical concerns, translation across the science-policy interface, and how the concept's normative aims and optimistic assumptions affect ES as a scientific approach. In particular, recent criticism has focused on how the concept is unable to address ecological complexity due to the limitations of the economic stock-flow model that ES is based on (Norgaard 2010). Acknowledging ecosystem disservices (EDS) (i.e., outcomes of ecosystem functions that negatively affect human communities) has been suggested as a way to account for this ecological complexity (McCauley 2006; Lyytimäki 2015).

Diverse animal communities influence ecosystem function in agroecosystems through positive and negative plant-animal interactions. Yet, past research has largely failed to examine multiple interactions that can have opposing impacts on agricultural production in a given context. We collected data on arthropod communities and yield quality and quantity parameters (fruit set, yield loss and net outcomes) in three major apple-growing regions in south-eastern Australia. We quantified the net yield outcome (accounting for positive and negative interactions) of multiple animal activities (pollination, fruit damage, biological control) across the entire growing season on netted branches, which excluded vertebrate predators of arthropods, and open branches. Net outcome was calculated as the number of undamaged fruit at harvest as a proportion of the number of blossoms (i.e., potential fruit yield). Vertebrate exclusion resulted in lower levels of fruit set and higher levels of arthropod damage to apples, but did not affect net outcomes. Yield quality and quantity parameters (fruit set, yield loss, net outcomes) were not directly associated with arthropod functional groups. Model variance and significant differences between the ratio of pest to beneficial arthropods between regions indicated that complex relationships between environmental factors and multiple animal interactions have a combined effect on yield. Our results show that focusing on a single crop stage, species group or ecosystem function/service can overlook important complexity in ecological processes within the system. Accounting for this complexity and quantifying the net outcome of ecological interactions within the system, is more informative for research and management of biodiversity and ecosystem services in agricultural landscapes.

Birds active in apple orchards in south-eastern Australia can contribute positively (e.g., control crop pests) or negatively (e.g., crop damage) to crop yields. Our study is the first to identify net outcomes of these activities, using six apple orchards, varying in management intensity, in south-eastern Australia as a study system. We also conducted a predation experiment using real and artificial codling moth (Cydia pomonella) larvae (a major pest in apple crops). We found that: (1) excluding birds from branches of apple trees resulted in an average of 12.8% more apples damaged by insects; (2) bird damage to apples was low (1.9% of apples); and (3) when trading off the potential benefits (biological control) with costs (bird damage to apples), birds provided an overall net benefit to orchard growers. We found that predation of real codling moth larvae was higher than for plasticine larvae, suggesting that plasticine prey models are not useful for inferring actual predation levels. Our study shows how complex ecological interactions between birds and invertebrates affect crop yield in apples, and provides practical strategies for improving the sustainability of orchard systems.