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Control of crop pests by shifting host plant availability and natural enemy activity at landscape scales has great potential to enhance the sustainability of agriculture. However, mainstreaming natural pest control requires improved understanding of how its benefits can be realized across a variety of agroecological contexts. Empirical studies suggest significant but highly variable responses of natural pest control to land-use change. Current ecological models are either too specific to provide insight across agroecosystems or too generic to guide management with actionable predictions. We suggest obtaining the full benefit of available empirical, theoretical, and methodological knowledge by combining trait-mediated understanding from correlative studies with the explicit representation of causal relationships achieved by mechanistic modeling. To link these frameworks, we adapt the concept of archetypes, or context-specific generalizations, from sustainability science. Similar responses of natural pest control to land-use gradients across cases that share key attributes, such as functional traits of focal organisms, indicate general processes that drive system behavior in a context-sensitive manner. Based on such observations of natural pest control, a systematic definition of archetypes can provide the basis for mechanistic models of intermediate generality that cover all major agroecosystems worldwide. Example applications demonstrate the potential for upscaling understanding and improving predictions of natural pest control, based on knowledge transfer and scientific synthesis. A broader application of this mechanistic archetype approach promises to enhance ecology's contribution to natural resource management across diverse regions and social-ecological contexts. ANR; BMBF; FORMAS; FWF; MINECO; NWO; PT-DLR; Helmholtz-Zentrum fur Umweltforschung; iDiv - German Research Foundation [DFG-FZT 118, 202548816]; Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS); SLU Centre for Biological Control; Strategic research area Biodiversity and Ecosystem services in a Changing Climate (BECC); US Dept. of Agriculture, National Institute of Food and Agriculture (NIFA) [2020-67021-32477]; Volkswagen Foundation [A118199] Published version 2013-2014 BiodivERsA/FACCE-JPI joint call for research proposals (project ECODEAL), with the national funders ANR, BMBF, FORMAS, FWF, MINECO, NWO and PT-DLR; Helmholtz-Zentrum fur Umweltforschung; iDiv, funded by the German Research Foundation, Grant/Award Numbers: DFG-FZT 118, 202548816; Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS); SLU Centre for Biological Control; Strategic research area Biodiversity and Ecosystem services in a Changing Climate (BECC); US Dept. of Agriculture, National Institute of Food and Agriculture (NIFA), Grant/Award Number: 2020-67021-32477; Volkswagen Foundation through a Freigeist Fellowship, Grant/Award Number: A118199

In the face of myriad environmental challenges associated with industrial agriculture, some farmers and researchers have looked to diversified farming systems as a promising alternative. Despite well-documented ecological benefits, diversification practices remain rare in many regions of the U.S, even amongst organic farmers. Our study focuses on organic farmers in the Central Coast region of California, an area that has played a crucial role in the rise of organic agriculture over the last several decades. Through 20 interviews with farmers who all grow lettuce and 8 interviews with technical assistance providers, we investigate the persistent barriers that growers in this region face in adopting diversification practices including cover cropping, compost application, crop rotation, insectary strips, and hedgerows. We find that high land rents, the predominance of short-term leases, stringent food safety standards, and other supply chain pressures significantly hamper the adoption of diversification practices. In order to surmount these barriers and increase adoption, solutions must be pursued at three interconnected levels: innovation at the farm level, and policy change at the technical and structural levels. Locally-informed, integrated, and innovative policies across these three levels must be explored to support the creation of a more resilient, sustainable, and equitable food system. USDA AFRI Grant [2019-6701929537]; NSF Coupled Natural Humans Systems Grant [1824871] Published version TB, AI, CK, PB, JO, KE, DK, HW, EO and LC acknowledge USDA AFRI Grant #2019-6701929537 and NSF Coupled Natural Humans Systems Grant #1824871.

Increasing diversity on farms can enhance many key ecosystem services to and from agriculture, and natural control of arthropod pests is often presumed to be among them. The expectation that increasing the size of monocultural crop plantings exacerbates the impact of pests is common throughout the agroecological literature. However, the theoretical basis for this expectation is uncertain; mechanistic mathematical models suggest instead that increasing field size can have positive, negative, neutral, or even nonlinear effects on arthropod pest densities. Here, we report a broad survey of crop field-size effects: across 14 pest species, 5 crops, and 20,000 field years of observations, we quantify the impact of field size on pest densities, pesticide applications, and crop yield. We find no evidence that larger fields cause consistently worse pest impacts. The most common outcome (9 of 14 species) was for pest severity to be independent of field size; larger fields resulted in less severe pest problems for four species, and only one species exhibited the expected trend of larger fields worsening pest severity. Importantly, pest responses to field size strongly correlated with their responses to the fraction of the surrounding landscape planted to the focal crop, suggesting that shared ecological processes produce parallel responses to crop simplification across spatial scales. We conclude that the idea that larger field sizes consistently disrupt natural pest control services is without foundation in either the theoretical or empirical record.

Variability in population densities is key to the ecology of natural systems but also has great implications for agriculture. Farmers' decisions are heavily influenced by their risk-aversion to pest outbreaks that result in major yield losses. However, the need for long-term pest population data across many farms has prevented researchers from exploring the drivers and implications of pest population variability. Here, we demonstrate the critical importance of population variability for sustainable farming by analyzing 13-yrs of pest densities across >1300 Spanish olive orchards and vineyards. Variable populations were more likely to cause major yield losses, but also occasionally created temporal windows when densities fell below insecticide spray thresholds. Importantly, environmental factors regulating pest variability were very distinct from factors regulating mean density, suggesting variability needs to be uniquely managed. Finally, we found diversifying landscapes may be a win-win for conservation and farmers, as diversified landscapes promote less abundant and less variable pest populations. Therefore, we encourage agricultural stakeholders to increase complexity of the landscapes surrounding their farms through conserving/restoring natural habitat and/or diversifying crops.

Recent foodborne illness outbreaks have heightened pressures on growers to deter wildlife from farms, jeopardizing conservation efforts. However, it remains unclear which species, particularly birds, pose the greatest risk to food safety. Using11,000 pathogen tests and 1565 bird surveys covering 139 bird species from across the western United States, we examined the importance of 11 traits in mediating wild bird risk to food safety. We tested whether traits associated with pathogen exposure (e.g., habitat associations, movement, and foraging strategy) and pace-of-life (clutch size and generation length) mediated foodborne pathogen prevalence and proclivities to enter farm fields and defecate on crops. Campylobacter spp. were the most prevalent enteric pathogen (8.0%), while Salmonella and Shiga-toxin producing Escherichia coli (STEC) were rare (0.46% and 0.22% prevalence, respectively). We found that several traits related to pathogen exposure predicted pathogen prevalence. Specifically, Campylobacter and STEC-associated virulence genes were more often detected in species associated with cattle feedlots and bird feeders, respectively. Campylobacter was also more prevalent in species that consumed plants and had longer generation lengths. We found that species associated with feedlots were more likely to enter fields and defecate on crops. Our results indicated that canopy-foraging insectivores were less likely to deposit foodborne pathogens on crops, suggesting growers may be able to promote pest-eating birds and birds of conservation concern (e.g., via nest boxes) without necessarily compromising food safety. As such, promoting insectivorous birds may represent a win-win-win for bird conservation, crop production, and food safety. Collectively, our results suggest that separating crop production from livestock farming may be the best way to lower food safety risks from birds. More broadly, our trait-based framework suggests a path forward for co-managing wildlife conservation and food safety risks in farmlands by providing a strategy for holistically evaluating the food safety risks of wild animals, including under-studied species.

Global frameworks to guide consistent monitoring of changes in human–nature interactions across space and time are needed to better understand how healthy ecosystems support societies and to inform policy design. Monitoring Essential Ecosystem Service Variables (EESVs) can provide a comprehensive picture of how links between nature and people are changing. A first proposed set of EESV classes comprises: ecological supply, anthropogenic contribution, demand, use, instrumental values, and relational values. Development of specific indicators of these classes for three exemplary ecosystem services (food from fisheries, crop pollination and wildlife viewing) confirms their readiness for global operationalization. The EESV classes will advance our ability to monitor progress towards achieving the Sustainable Development Goals.

Understanding how and why animals use the environments where they occur is both foundational to behavioral ecology and essential to identify critical habitats for species conservation. However, some behaviors are more difficult to observe than others, which can bias analyses of raw observational data. To our knowledge, no method currently exists to model how animals use different environments while accounting for imperfect behavior-specific detection probability. We developed an extension of a binomial N-mixture model (hereafter the behavior N-mixture model) to estimate the probability of a given behavior occurring in a particular environment while accounting for imperfect detection. We then conducted a simulation to validate the model's ability to estimate the effects of environmental covariates on the probabilities of individuals performing different behaviors. We compared our model to a naïve model that does not account for imperfect detection, as well as a traditional N-mixture model. Finally, we applied the model to a bird observation data set in northwest Costa Rica to quantify how three species behave in forests and farms. Simulations and sensitivity analyses demonstrated that the behavior N-mixture model produced unbiased estimates of behaviors and their relationships with predictor variables (e.g., forest cover, habitat type). Importantly, the behavior N-mixture model accurately characterized uncertainty, unlike the naïve model, which often suggested erroneous effects of covariates on behaviors. When applied to field data, the behavior N-mixture model suggested that Hoffmann's woodpecker (Melanerpes hoffmanii) and Inca dove (Columbina inca) behaved differently in forested versus agricultural habitats, while turquoise-browed motmot (Eumomota superciliosa) did not. Thus, the behavior N-mixture model can help identify habitats that are essential to a species' life cycle (e.g., where individuals nest, forage) that nonbehavioral models would miss. Our model can greatly improve the appropriate use of behavioral survey data and conclusions drawn from them. In doing so, it provides a valuable path forward for assessing the conservation value of alternative habitat types.

Farmland diversification practices (i.e., methods used to produce food sustainably by enhancing biodiversity in cropping systems) are sometimes considered beneficial to both agriculture and biodiversity, but most studies of these practices rely on species richness, diversity, or abundance as a proxy for habitat quality. Biodiversity assessments may miss early clues that populations are imperiled when species presence does not imply persistence. Physiological stress indicators may help identify low-quality habitats before population declines occur. We explored how avian stress indicators respond to on-farm management practices and surrounding seminatural area (1-km radius) across 21 California strawberry farms. We examined whether commonly used biodiversity metrics correlate with stress responses in wild birds. We used ∼1000 blood and feather samples and body mass and wing chord measurements, mostly from passerines, to test the effects of diversification practices on four physiological stress indicators: heterophil to lymphocyte ratios (H:L), body condition, hematocrit values, and feather growth rates of individual birds. We then tested the relationship between physiological stress indicators and species richness, abundance, occurrence, and diversity derived from 285 bird point count surveys. After accounting for other biological drivers, landscape context mediated the effect of local farm management on H:L and body condition. Local diversification practices were associated with reduced individual stress in intensive agricultural landscapes but increased it in landscapes surrounded by relatively more seminatural area. Feathers grew more slowly in landscapes dominated by strawberry production, suggesting that nutritional condition was lower here than in landscapes with more crop types and seminatural areas. We found scant evidence that species richness, abundance, occurrence, or diversity metrics were correlated with the individual's physiological stress, suggesting that reliance on these metrics may obscure the impacts of management on species persistence. Our findings underscore the importance of considering landscape context when designing local management strategies to promote wildlife conservation.Algunas veces se considera a las prácticas de diversificación agrícola (es decir, los métodos usados para producir alimentos de manera sustentable mediante el enriquecimiento de la biodiversidad en los sistemas de cultivo) como benéficas para la agricultura y la biodiversidad, pero la mayoría de los estudios sobre estas prácticas dependen de la riqueza, abundancia o diversidad de especies como indicadores de la calidad del hábitat. Las valoraciones de la biodiversidad pueden ignorar las señales tempranas de una población en peligro cuando la presencia de la especie no implica persistencia. Los indicadores de estrés fisiológico pueden auxiliar en la identificación de hábitats de baja calidad antes de que ocurra la declinación poblacional. Analizamos las respuestas de los indicadores de estrés en aves al manejo en las granjas y áreas seminaturales circundantes (1 km de radio) de 21 cultivos de fresas en California. Evaluamos si las medidas comunes de biodiversidad se correlacionan con las respuestas al estrés de las aves silvestres. Usamos aproximadamente mil muestras de sangre y plumas y medidas de masa corporal y cuerda alar, la mayoría de paseriformes, para analizar los efectos de las prácticas de diversificación sobre cuatro indicadores de estrés fisiológico: la relación heterófilos/linfocitos (H:L), condición corporal; valores hematocritos; y la tasa de crecimiento de las plumas en aves individuales. Después probamos la relación entre los indicadores de estrés fisiológicos y la riqueza, abundancia, presencia y diversidad de especies tomadas de 285 conteos por puntos de aves. Después de considerar otros factores biológicos, el contexto del paisaje medió el efecto de la gestión de las granjas locales sobre la H:L y la condición corporal. Las prácticas locales de diversificación estuvieron asociadas con una reducción en el estrés individual en los paisajes con agricultura intensiva; sin embargo, el estrés aumentó en los paisajes rodeados por áreas relativamente más seminaturales. Encontramos poca evidencia que respalde que las medidas de riqueza, abundancia, presencia y diversidad de especies estuvieran correlacionadas con el estrés fisiológico de los individuos, lo que sugiere que depender de estas medidas puede nublar el impacto de la gestión sobre la persistencia de las especies. Nuestros descubrimientos apuntalan lo importante que es considerar el contexto del paisaje cuando se diseñan las estrategias de gestión local para promover la conservación de la fauna.农田多样化实践(即通过提高耕作系统的生物多样性来可持续生产的方法)有时被认为有益于农业和生物多样性, 但对这些实践的研究大多依赖于物种丰富度、多样性或丰度作为栖息地质量的评估指标。当物种的出现并不意味着持续存在时, 生物多样性评估可能会错过种群受到威胁的早期线索。生理压力指标可能有助于在种群数量下降前识别低质量的栖息地。本研究探讨了 21 个加州草莓农场中鸟类压力指标对农场管理和周围半自然区域 (半径 1 公里) 的响应。我们研究了常用的生物多样性指标是否与野生鸟类的压力响应相关。我们使用了主要来自于雀形目鸟类的约 1,000 份血液和羽毛样本以及身体质量和翼弦的测量值, 以检验多样化实践对4个生理压力指标的影响, 这些指标分别为异嗜性细胞与淋巴细胞的比率 (H:L)、身体状况、血细胞压积值和鸟类个体的羽毛生长速度。接下来, 我们检验了生理压力指标与 285 项鸟类点计数调查得到的物种丰富度、丰度、出现率和多样性之间的关系。在考虑了其他生物驱动因素后, 我们发现景观环境介导了当地农场管理对 H:L 和身体状况的影响。在密集型农业景观中, 当地的多样化实践伴随着个体压力的降低, 但在被相对较多的半自然区域包围的景观中, 多样化实践则会导致个体压力增加。在以草莓生产为主的景观中, 鸟类羽毛生长更慢, 表明这里的营养状况不如有更多作物类型的景观和半自然区域的景观。没有充足证据表明物种丰富度、丰度、出现率或多样性指标与个体生理压力相关, 这表明对这些指标的依赖可能掩盖了管理对物种续存的影响。我们的研究结果强调了在设计当地管理策略以促进野生动物保护时考虑景观环境的重要性。【翻译: 胡怡思; 审校: 聂永刚】.

Aims Recent foodborne disease outbreaks have caused farmers to re-evaluate their practices. In particular, concern that soil amendments could introduce foodborne pathogens onto farms and promote their survival in soils has led farmers to reduce or eliminate the application of animal-based composts. However, organic amendments (such as composts and cover crops) could bolster food safety by increasing soil microbial diversity and activity, which can act as competitors or antagonists and reduce pathogen survival. Methods and Results Leveraging a study of a 27-year experiment comparing organic and conventional soil management, we evaluate the impacts of composted poultry litter and cover crops on soil chemistry, bacterial communities and survival of Salmonella enterica and Listeria monocytogenes. We found that bacterial community composition strongly affected pathogen survival in soils. Specifically, organic soils managed with cover crops and composts hosted more macronutrients and bacterial communities that were better able to suppress Salmonella and Listeria. For example, after incubating soils for 10 days at 20°C, soils without composts retained fourfold to fivefold more Salmonella compared to compost-amended soils. However, treatment effects dissipated as bacterial communities converged over the growing season. Conclusions Our results suggest that composts and cover crops may be used to build healthy soils without increasing foodborne pathogen survival. Significance and Impact of the Study Our work suggests that animal-based composts do not promote pathogen survival and may even promote bacterial communities that suppress pathogens. Critically, proper composting techniques are known to reduce pathogen populations in biological soil amendments of animal origin, which can reduce the risks of introducing pathogens to farm fields in soil amendments. Thus, animal-based composts and cover crops may be a safe alternative to conventional fertilizers, both because of the known benefits of composts for soil health and because it may be possible to apply amendments in such a way that food-safety risks are mitigated rather than exacerbated.

Soil and soil biodiversity play critical roles in Nature's Contributions to People (NCP) # 10, defined as Nature's ability to regulate direct detrimental effects on humans, and on human-important plants and animals, through the control or regulation of particular organisms considered to be harmful. We provide an overview of pathogens in soil, focusing on human and crop pathogens, and discuss general strategies, and examples, of how soils' extraordinarily diverse microbial communities regulate soil-borne pathogens. We review the ecological principles underpinning the regulation of soil pathogens, as well as relationships between pathogen suppression and soil health. Mechanisms and specific examples are presented of how soil and soil biota are involved in regulating pathogens of humans and plants. We evaluate how specific agricultural management practices can either promote or interfere with soil's ability to regulate pathogens. Finally, we conclude with how integrating soil, plant, animal and human health through a ‘One Health’ framework could lead to more integrated, efficient and multifunctional strategies for regulating detrimental organisms and processes. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

The outcome of the ongoing biodiversity crisis depends on the capacity of the Earth’s wildlife to persist in working landscapes. Yet, the species that occupy working landscapes are often distinct from those in protected areas, with a large group of “sensitive species” thought to rarely venture into human‐dominated landscapes. As governments have committed to restoring degraded lands world‐wide, determining whether and how working landscapes can be restored to benefit sensitive species remains a major challenge. We surveyed Neotropical birds across Northwestern Costa Rica in protected areas, farms and forests embedded within working landscapes. We analysed community composition to understand how gradients of forest cover, fragmentation and regional precipitation determine how conserving (or restoring) tropical forests in working landscapes could safeguard entire communities, especially sensitive species with limited ranges. We found agricultural sites maintained relatively high bird diversity but hosted very distinct communities from those found in protected areas. The average range size of species found in agricultural communities was double the size of species in protected areas. However, high forest cover sites in working landscapes housed bird communities with small range sizes that were equivalent to those in nearby protected areas, despite being twice as fragmented and significantly more disturbed. The effect of local forest cover on bird composition was contingent on both landscape context and regional climate. When local forest cover increased in wetter regions and more forested landscapes, bird communities in working landscapes exhibited a stronger shift towards the assemblages found in protected areas. Specifically, we found that reforesting the wettest sites would increase similarity to protected areas fourfold compared to only a twofold increase in the driest sites. Synthesis and applications. Despite experiencing much more fragmentation and degradation than protected areas, forests in Costa Rican working landscapes can maintain bird communities that strongly resemble those found in protected areas. This suggests that conserving or restoring forests in working landscapes, particularly within wetter regions and already forested landscapes, may safeguard bird communities when creating protected areas is infeasible.

AIM: Changes in climate and land use are modifying biodiversity worldwide. Yet it remains unclear how both drivers interact to structure communities and determine patterns in taxonomic, phylogenetic and functional diversity at local scales. We focused on bird diversity and asked: how do precipitation and forest cover gradients interactively structure these elements of avian diversity? LOCATION: Guanacaste, North‐western Costa Rica. METHODS: We quantified changes in the abundance and composition of bird communities along independent gradients of regional precipitation, local forest cover and landscape forest cover that serve as proxies for climate drying and habitat conversion. We conducted point counts at 150 sites and statistically accounted for imperfect detection to test how environmental variation shaped community‐wide diversity metrics. RESULTS: We found that the three dimensions of diversity diverged in their responses to environmental gradients. Specifically, species richness increased linearly with precipitation, reached maximum values with intermediate tree cover at local scales and peaked at high levels of landscape tree cover. While phylogenetic diversity did not vary strongly across any gradient, functional diversity increased monotonically with both local and landscape‐level tree cover. Maximum values of functional diversity only occurred in large patches of forest where the tree cover was >75% at both local and landscape scales. Contrary to our expectations, we did not detect significant interactions between precipitation and tree cover gradients on any metric of local bird diversity. MAIN CONCLUSIONS: Our findings suggest that taxonomic diversity was more sensitive to environmental gradients than functional and phylogenetic diversity. The lack of synergies between precipitation and forest cover gradients on alpha diversity, at least in this system, simplifies the prospects of predicting future biodiversity change at local scales as our results suggest that climate change and land use act independently of one another.

Countryside biogeography seeks to explain the distribution of wildlife in human-dominated landscapes. We review the theoretical and empirical progress towards this goal, assessing what forces control the presence, abundance, and richness of species in anthropogenic and natural habitats, based on characteristics of the landscape and the species themselves. Recent modifications of species-area relationships that incorporate multiple habitat types have improved understanding of species diversity in countryside landscapes. Attempts to understand why species affiliate with human-modified habitats have been met with only partial success. Though traits frequently explain associations with human-modified habitats within studies, explanatory traits are only rarely shared between studies, regions, or taxa. Nonetheless, greater attention to the regional and climatological context of countryside landscapes has uncovered that (i) species that associate with human-modified habitats within landscapes tend to occur primarily in warm and/or dry biomes at regional scales and (ii) species that rely exclusively on human-modified habitats in cool or wet regions may be restricted to natural habitats in warm or dry regions. There remains a pressing need to determine how biodiversity can best be supported within landscapes to preserve nature and maximize ecosystem service benefits for humans. Future work in countryside biogeography must identify how land-use change interacts with other global stressors (e.g., climate change), determine how extinction debt and population sinks influence diversity, quantify the cascading effects of community changes on ecosystem services, and elucidate the evolutionary history and origins of species that today dwell in the countryside.

Experimental exclosure of birds and bats constitutes a powerful tool to study the impacts of wildlife on pests and crop yields in agricultural systems. Though widely utilized, exclosure experiments are not standardized across studies. Indeed, key differences surrounding the design, materials, and protocols for implementing field-based exclosure experiments of flying vertebrates increase heterogeneity across studies, and limit our understanding of biodiversity-friendly land use management. We reviewed the available literature on studies in which bird and bat exclosures were applied to study pest control in agricultural settings, and isolated 30 studies from both tropical and temperate land use systems, involving 12 crop types across 14 countries. Focusing on exclosure effects on crop yield, we analyzed effect detectability for a subset of suitable data. We then analyzed the potential of exclosure methods and possible extensions to improve our understanding of complex food webs and ecosystem services affecting the productivity of agricultural systems. While preferences exist in materials (e.g., nylon nets and bamboo frames), experimental exclosure studies of birds and bats differed greatly in their respective design, related costs, and effort — limiting the generalization and transferability of results at larger spatial scales. Most studies were based on experiments conducted in the United States and the Neotropics, mainly in coffee and cacao farms. A lack of preliminary or long-term data with repeated measurements makes it impossible to apply power analysis in most studies. Common constraints include, among other things, the choice of material and experimental duration, as well as the consideration of local versus landscape factors. We discuss such limitations, related common pitfalls, and options for optimization to inform improved planning, design, and execution of exclosure studies. By doing so, we aim to promote more comparable and transferable approaches in future field research on biodiversity-mediated ecosystem services.

Recent synthesis studies have shown inconsistent responses of crop pests to landscape composition, imposing a fundamental limit to our capacity to design sustainable crop protection strategies to reduce yield losses caused by insect pests. Using a global dataset composed of 5242 observations encompassing 48 agricultural pest species and 26 crop species, we tested the role of pest traits (exotic status, host breadth and habitat breadth) and environmental context (crop type, range in landscape gradient and climate) in modifying the pest response to increasing semi-natural habitats in the surrounding landscape. For natives, increasing semi-natural habitats decreased the abundance of pests that exploit only crop habitats or that are highly polyphagous. On the contrary, populations of exotic pests increased with an increasing cover of semi-natural habitats. These effects might be related to changes in host plants and other resources across the landscapes and/or to modified top-down control by natural enemies. The range of the landscape gradient explored and climate did not affect pests, while crop type modified the response of pests to landscape composition. Although species traits and environmental context helped in explaining some of the variability in pest response to landscape composition, the observed large interspecific differences suggest that a portfolio of strategies must be considered and implemented for the effective control of rapidly changing communities of crop pests in agroecosystems.

The current biodiversity crisis involves major shifts in biological communities at local and regional scales. The consequences for Earth's life‐support systems are increasingly well‐studied, but knowledge of how community shifts affect cultural services associated with wildlife lags behind. We integrated bird census data (3 years across 150 point‐count locations) with questionnaire surveys (>400 people) to evaluate changes in culturally important species across climate and land‐use gradients in Costa Rica. For farmers, urbanites, and birdwatchers alike, species valued for identity, bequest, birdwatching, acoustic aesthetics, and education were more likely to occupy wetter regions and forested sites, whereas disliked species tended to occupy drier and deforested sites. These results suggest that regional climate drying and habitat conversion in the Neotropics are likely to threaten the most culturally important bird species. This study provides a novel and generalizable pathway for assessing the effects of environmental changes on cultural services and integrating the sociocultural and ecological dimensions of biodiversity.

Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. Yet landscapes are rarely managed to suppress pests, in part because researchers seldom measure key variables related to pest outbreaks and insecticides that drive management decisions. We used a 13‐year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. At harvest, we found pest outbreaks increased four‐fold in simplified, vineyard‐dominated landscapes compared to complex landscapes in which vineyards are surrounded by semi‐natural habitats. Similarly, insecticide applications doubled in vineyard‐dominated landscapes but declined in vineyards surrounded by shrubland. Importantly, pest population stochasticity would have masked these large effects if numbers of study sites and years were reduced to typical levels in landscape pest‐control studies. Our results suggest increasing landscape complexity may mitigate pest populations and insecticide applications. Habitat conservation represents an economically and environmentally sound approach for achieving sustainable grape production., Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. We used a 13‐year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. Our results suggest increasing landscape complexity may mitigate pest outbreaks and insecticide applications.

Adaptation across climate gradients can provide the raw material needed for evolutionary response to climate change. In migratory species, studies of local climate adaptation are made challenging by seasonal movement, where it is unclear to what extent individuals track their local climate niches across the annual cycle. In the migratory songbird yellow warbler ( Setophaga petechia ), we test the hypothesis that individuals track similar climates between their breeding and wintering ranges. Further, we examine whether adaptation to local climate might lead to morphological differences among populations and different demographic responses to temporal climate variability. We find a correlation between wintering and breeding precipitation but not temperature regimes at the level of the individual bird. Specifically, birds from the driest wintering regions migrate to the driest breeding regions. Additionally, we find an association between bill size and breeding season precipitation which, given documented climate-associated genomic variation, suggests adaptation to local precipitation gradients might exist on the breeding grounds. Finally, we show geographic variation in the effect of precipitation on demography, with higher precipitation associated with population increases in some regions and declines in others. Taken together, our results suggest that variation in climate optima exists across the breeding range of yellow warblers and provide a potential mechanism for parallel selection across the annual cycle.

Some birds are viewed as pests and vectors of foodborne pathogens in farmlands, yet birds also benefit growers by consuming pests. While many growers seek to prevent birds from accessing their farms, few studies have attempted to quantify the net effects of bird services and disservices, let alone how net effects shift across farm management strategies. We quantified the net effect of birds on crop production across 20 California strawberry (Fragaria × ananassa) farms that varied in local management practices and landscape context. We surveyed farms for berry damage and bird droppings (as potential sources of pathogens) and implemented a large-scale exclusion experiment to quantify the impact of birds on production. We found that birds had only a slightly negative overall impact on strawberry production, reducing economic value by 3.6%. Direct bird damage and intraguild predation contributed equally to this net effect, underscoring the importance of indirect trophic interactions that may be less apparent to growers. In simple landscapes (e.g., low proportions of surrounding seminatural habitat), birds provided pest control in the interiors of farm fields, and costs from bird damage to crops peaked at field edges. In complex landscapes (e.g., high proportions of seminatural habitat), birds were more likely to disrupt pest control by feeding as intraguild predators. Nonetheless, seminatural habitat dampened bird services and disservices, and our models predicted that removing habitat around farm fields would increase costs from bird damage to crops by up to 76%. Fecal contamination of crops was extremely rare (0.01%). However, both fecal contamination and bird damage did increase on farms with higher densities of fencing and wires, where birds often perch. Our results demonstrate that maintaining seminatural habitat around farms may enhance bird diversity and mitigate bird damage without increasing food safety risks. We also show that the net effects of birds depend on farming context and vary in complex ways in relation to locations within a farm, local farm attributes, and the surrounding landscape. This context-specific variation must be considered in order to optimize the management of wild birds in agroecosystems.

Natural control of crop pests has the potential to complement or replace intensive agricultural practices, but its mainstream application requires reliable predictions in diverse socioecological settings. In lack of a widely accepted model of natural pest control, we review existing modelling approaches and critically examine their potential to provide understanding and predictions across agricultural landscapes. Models that explicitly represent the underlying mechanisms are better positioned to represent the diversity and context sensitivity of natural pest control than correlative models. Such mechanistic models have used diverse techniques to represent crop-pest-enemy combinations at various spatiotemporal scales. However, certain regions of the world and socioeconomic aspects of natural pest control are underrepresented, while modelling approaches are restricted by a fundamental trade-off between generality and realism. We propose that modelling natural pest control across agroecosystems requires a framework of context-specific generalizations, based on empirical evidence and theoretical expectations. Reviewed models of natural pest control indicate potential attributes of such a general predictive framework.

Some bird species often benefit farmers by suppressing invertebrate crop pests, yet birds are rarely considered in integrated pest management (IPM) strategies. This is likely because some bird species pose risks to farmers through crop damage, intraguild predation, and food safety concerns. Nonetheless, the benefits of some bird species on crop production are often substantial. Therefore, understanding when birds are most likely to enhance crop production (and when they are most likely to depress it) is crucial for designing effective IPM strategies. Here, we briefly review the literature on birds in agricultural systems, discuss examples of how birds can provide services and disservices to crops, examine factors that influence the net effects of birds, and discuss emerging tools that will help fill key knowledge gaps surrounding the complex roles of birds in agricultural systems.

Plants influence the atmosphere through fluxes of carbon, water and energy1, and can intensify drought through land–atmosphere feedback effects2–4. The diversity of plant functional traits in forests, especially physiological traits related to water (hydraulic) transport, may have a critical role in land–atmosphere feedback, particularly during drought. Here we combine 352 site-years of eddy covariance measurements from 40 forest sites, remote-sensing observations of plant water content and plant functional-trait data to test whether the diversity in plant traits affects the response of the ecosystem to drought. We find evidence that higher hydraulic diversity buffers variation in ecosystem flux during dry periods across temperate and boreal forests. Hydraulic traits were the predominant significant predictors of cross-site patterns in drought response. By contrast, standard leaf and wood traits, such as specific leaf area and wood density, had little explanatory power. Our results demonstrate that diversity in the hydraulic traits of trees mediates ecosystem resilience to drought and is likely to have an important role in future ecosystem–atmosphere feedback effects in a changing climate.

Biological communities face multiple global changes simultaneously, and predicting how they will respond remains a key challenge. Co‐tolerance theory offers a framework for understanding how species‐level responses to multiple stressors affect community properties. Co‐tolerance theory predicts that positive correlations in species responses (i.e. species that are susceptible to one stressor are more likely to be highly susceptible to a second) lessen total species loss, essentially because species cannot be eliminated from a community twice. However, it is unclear whether several of the tenets of co‐tolerance theory describe real‐world communities, and what consequences result from such deviations. Here, we use an empirical dataset of bird community response to land‐use change over a climate gradient to examine co‐tolerance theory's tenet that environmental changes only harm species (not benefit them). We show that this tenet is not met, and then use simulations to examine how predictions of total species richness and community intactness vary when multiple environmental changes both harm and benefit particular species in the community. Finally, we conduct a sensitivity analysis, examining how the average species response to environmental change, as well as the variance among species, can further alter predictions. Overall, we find that predictions of co‐tolerance theory can break down when communities contain species that benefit from some environmental changes. As a result, the presence of multiple environmental changes can either compound or mitigate species loss when species’ responses are positively correlated, preventing a one‐size‐fits‐all statement regarding the effects of correlated responses. This finding highlights the need to carefully consider the underlying mechanisms of community change when making policy assessments regarding the consequences of correlations of species responses to environmental impacts.

Natural control of invertebrate crop pests has the potential to complement or replace conventional insecticide-based practices, but its mainstream application is hampered by predictive unreliability across agroecosystems. Inconsistent responses of natural pest control to changes in landscape characteristics have been attributed to ecological complexity and system-specific conditions. Here, we review agroecological models and their potential to provide predictions of natural pest control across agricultural landscapes. Existing models have used a multitude of techniques to represent specific crop-pest-enemy systems at various spatiotemporal scales, but less wealthy regions of the world are underrepresented. A realistic representation of natural pest control across systems appears to be hindered by a practical trade-off between generality and realism. Nonetheless, observations of context-sensitive, trait-mediated responses of natural pest control to land-use gradients indicate the potential of ecological models that explicitly represent the underlying mechanisms. We conclude that modelling natural pest control across agroecosystems should exploit existing mechanistic techniques towards a framework of contextually bound generalizations. Observed similarities in causal relationships can inform the functional grouping of diverse agroecosystems worldwide and the development of the respective models based on general, but context-sensitive, ecological mechanisms. The combined use of qualitative and quantitative techniques should allow the flexible integration of empirical evidence and ecological theory for robust predictions of natural pest control across a wide range of agroecological contexts and levels of knowledge availability. We highlight challenges and promising directions towards developing such a general modelling framework. (Less)

Earth is experiencing multiple global changes that will, together, determine the fate of many species. Yet, how biological communities respond to concurrent stressors at local-to-regional scales remains largely unknown. In particular, understanding how local habitat conversion interacts with regional climate change to shape patterns in β-diversity-differences among sites in their species compositions-is critical to forecast communities in the Anthropocene. Here, we study patterns in bird β-diversity across land-use and precipitation gradients in Costa Rica. We mapped forest cover, modeled regional precipitation, and collected data on bird community composition, vegetation structure, and tree diversity across 120 sites on 20 farms to answer three questions. First, do bird communities respond more strongly to changes in land use or climate in northwest Costa Rica? Second, does habitat conversion eliminate β-diversity across climate gradients? Third, does regional climate control how communities respond to habitat conversion and, if so, how? After correcting for imperfect detection, we found that local land-use determined community shifts along the climate gradient. In forests, bird communities were distinct between sites that differed in vegetation structure or precipitation. In agriculture, however, vegetation structure was more uniform, contributing to 7%-11% less bird turnover than in forests. In addition, bird responses to agriculture and climate were linked: agricultural communities across the precipitation gradient shared more species with dry than wet forest communities. These findings suggest that habitat conversion and anticipated climate drying will act together to exacerbate biotic homogenization.

Protected areas are considered a primary place for biodiversity conservation; however, under current rates of global change, it is increasingly important to understand how effective existing reserves are in protecting biodiversity. We examine how U.S. National Park Service lands on the Colorado Plateau (USA) contribute to biodiversity conservation and whether local extirpations have led to an erosion of regional biodiversity. Species range adjustments are among the first signs of biome change, so tracing regional biodiversity change is an efficient way to identify the early phases of major biome shifts. We use analysis of nested mammalian species assemblages to 1) determine if Colorado Plateau mammal assemblages are significantly nested and, 2) clarify which properties of protected lands correlate with nestedness and species richness. We compare species lists from surveys of contemporary resident species to lists from historical range maps that record species ranges from the ~ 100 years ago, and find that reserves retain essentially the same mammalian diversity and biogeographic patterns that were present in the early 1900s. This suggests that “faunal relaxation” has not occurred in this landscape, and that mammal diversity conservation in these lands has been largely effective for most species thus far. However, anthropogenic climate change is affecting the environmental conditions that influence species distributions, lands surrounding parks are under pressure for human uses, and increasing numbers of visitors are using parks while financial resources are ever more uncertain. Therefore, understanding how nestedness patterns are governed by human-dominated landscapes will be an important conservation tool for quickly assessing diversity change in the future.

The functional trait diversity of species assemblages can predict the provision of ecosystem services such as pollination and carbon sequestration, but it is unclear whether the same trait‐based framework can be applied to identify the factors that underpin cultural ecosystem services and disservices. To explore the relationship between traits and the contribution of species to cultural ecosystem services and disservices, we conducted 404 questionnaire surveys with birdwatchers and local residents in Guanacaste, Costa Rica. We used an information–theoretic approach to identify which of 20 functional traits for 199 Costa Rican bird species best predicted their cultural ecosystem service scores related to birdwatching, acoustic aesthetics, education and local identity, as well as disservices (e.g. harm to crops). We found that diet was the most important variable explaining perceptions of cultural ecosystem service and disservice providers. Aesthetic traits such as plumage colour and pattern were important in explaining birdwatching scores. We also found people have a high affinity for forest‐affiliated birds. The insight that functional traits can explain variation among cultural perspectives on values derived from birds offers a first step towards a trait‐based system for understanding the species attributes that underpin cultural ecosystem services and disservices.

Despite decades of study, conservation biocontrol via manipulation of landscape elements has not become a mainstream strategy for pest control. Meanwhile, conservation groups and governments rarely consider the impacts of land management on pest control, and growers can even fear that conservation biocontrol strategies may exacerbate pest problems. By finding leverage points among these actors, there may be opportunities to align them to promote more widespread adoption of conservation biological control at the landscape-scale. But are ecologists measuring the right things and presenting the right evidence to enable such alignment? We articulate key concerns of growers, conservation groups, and governments with regards to implementing conservation biological control at the landscape scale and argue that if ecologists want to gain more traction, we need to reconsider what we measure, for what goals, and for which audiences. A wider set of landscape objectives that ecologists should consider in our measurements include risk management for growers and co-benefits of multifunctional landscapes for public actors. Ecologists need to shift our paradigm toward longer-term, dynamic measurements, and build cross-disciplinary understanding with socioeconomic and behavioral sciences, to enable better integration of the objectives of these diverse actors that will be necessary for landscape management for conservation biocontrol to achieve its full potential.

The meanings attached to animals speak to context-specific socio-political differences that are crucial to the success of conservation and wildlife management programs. The social construction of a...

Land-use change and climate change are driving a global biodiversity crisis. Yet, how species' responses to climate change are correlated with their responses to land-use change is poorly understood. Here, we assess the linkages between climate and land-use change on birds in Neotropical forest and agriculture. Across > 300 species, we show that affiliation with drier climates is associated with an ability to persist in and colonise agriculture. Further, species shift their habitat use along a precipitation gradient: species prefer forest in drier regions, but use agriculture more in wetter zones. Finally, forest-dependent species that avoid agriculture are most likely to experience decreases in habitable range size if current drying trends in the Neotropics continue as predicted. This linkage suggests a synergy between the primary drivers of biodiversity loss. Because they favour the same species, climate and land-use change will likely homogenise biodiversity more severely than otherwise anticipated.