First large-scale study reveals important losses of managed honey bee and stingless bee colonies in Latin America

Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees (Apis mellifera), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeepers and 165 meliponiculturists participated in the 2-year survey (2016-2017 and 2017-2018). On average, 30.4% of honey bee colonies and 39.6% of stingless bee colonies were lost per year across the region. Summer losses were higher than winter losses in stingless bees (30.9% and 22.2%, respectively) but not in honey bees (18.8% and 20.6%, respectively). Colony loss increased with operation size during the summer in both honey bees and stingless bees and decreased with operation size during the winter in stingless bees. Furthermore, losses differed significantly between countries and across years for both beekeepers and meliponiculturists. Overall, winter losses of honey bee colonies in Latin America (20.6%) position this region between Europe (12.5%) and the United States (40.4%). These results highlight the magnitude of bee colony losses occurring in the region and suggest difficulties in maintaining overall colony health and economic survival for beekeepers and meliponiculturists.

Integrating public engagement to intensify pollination services through ecological restoration

Globally, human activities impose threats to nature and the provision of ecosystem services, such as pollination. In this context, ecological restoration provides opportunities to create managed landscapes that maximize biodiversity conservation and sustainable agriculture, e.g., via provision of pollination services. Managing pollination services and restoration opportunities requires the engagement of distinct stakeholders embedded in diverse social institutions. Nevertheless, frameworks toward sustainable agriculture often overlook how stakeholders interact and access power in social arenas. We present a perspective integrating pollination services, ecological restoration, and public engagement for biodiversity conservation and agricultural production. We highlight the importance of a comprehensive assessment of pollination services, restoration opportunities identification, and a public engagement strategy anchored in institutional analysis of the social arenas involved in restoration efforts. Our perspective can therefore guide the implementation of practices from local to country scales to enhance biodiversity conservation and sustainable agriculture.

Functional Traits in Bees: the Role of Body Size and Hairs in the Pollination of a Passiflora Crop

Pollination is a vitally important function in nature and becomes an ecosystem service because it influences the food and nutritional security for people. However, the contribution of different functional traits of insects for pollen transport of plants is still poorly known. We explore the relationship between pollinator insect functional traits and the transport of pollen of sweet granadilla (Passiflora ligularis Juss) in eight crops. We sampled flower-visiting insects of this crop and recorded 10 functional traits (five by direct measurements and five from the literature) that were related to the amount of pollen carried by each insect. Bees (Apidae) were not only the most abundant insects but also the ones that loaded the highest amounts of pollen. Within these, the most abundant species was the exotic common honeybee (Apis mellifera (Linnaeus)) making up almost half of the specimens collected; however, this bee carried less pollen grains than other native bees. Bombus hortulanus (Smith) was one of the large-bodied native bees that carried more sweet granadilla pollen, despite not being an abundant species in the community. Body size was the most important trait determining the transport of sweet granadilla pollen, while the traits related to body hairs were not significant for the body's pollen load. None of the functional traits evaluated was influenced by taxonomy at species-level. Our results suggest that large body sizes in bees are the most important traits in granadilla pollen transport, regardless of other changes in composition and structure of pollinating insect assemblages in the crop.

AgroEcoList 1.0: A checklist to improve reporting standards in ecological research in agriculture

Many publications lack sufficient background information (e.g. location) to be interpreted, replicated, or reused for synthesis. This impedes scientific progress and the application of science to practice. Reporting guidelines (e.g. checklists) improve reporting standards. They have been widely taken up in the medical sciences, but not in ecological and agricultural research. Here, we use a community-centred approach to develop a reporting checklist (AgroEcoList 1.0) through surveys and workshops with 23 experts and the wider agroecological community. To put AgroEcoList in context, we also assessed the agroecological community's perception of reporting standards in agroecology. A total of 345 researchers, reviewers, and editors, responded to our survey. Although only 32% of respondents had prior knowledge of reporting guidelines, 76% of those that had said guidelines improved reporting standards. Overall, respondents agreed on the need of AgroEcolist 1.0; only 24% of respondents had used reporting guidelines before, but 78% indicated they would use AgroEcoList 1.0. We updated AgroecoList 1.0 based on respondents' feedback and user-testing. AgroecoList 1.0 consists of 42 variables in seven groups: experimental/sampling set-up, study site, soil, livestock management, crop and grassland management, outputs, and finances. It is presented here, and is also available on github (https://github.com/AgroecoList/Agroecolist). AgroEcoList 1.0 can serve as a guide for authors, reviewers, and editors to improve reporting standards in agricultural ecology. Our community-centred approach is a replicable method that could be adapted to develop reporting checklists in other fields. Reporting guidelines such as AgroEcoList can improve reporting standards and therefore the application of research to practice, and we recommend that they are adopted more widely in agriculture and ecology.

Bee and non-bee pollinator importance for local food security

Pollinators are critical for food security; however, their contribution to the pollination of locally important crops is still unclear, especially for non-bee pollinators. We reviewed the diversity, conservation status, and role of bee and non-bee pollinators in 83 different crops described either as important for the global food market or of local importance. Bees are the most commonly recorded crop floral visitors. However, non-bee pollinators are frequently recorded visitors to crops of local importance. Non-bee pollinators in tropical ecosystems include nocturnal insects, bats, and birds. Importantly, nocturnal pollinators are neglected in current diurnal-oriented research and are experiencing declines. The integration of non-bee pollinators into scientific studies and conservation agenda is urgently required for more sustainable agriculture and safeguarding food security for both globally and locally important crops.

Pollinator Deficits, Food Consumption, and Consequences for Human Health: A Modeling Study

BACKGROUND

Animal pollination supports agricultural production for many healthy foods, such as fruits, vegetables, nuts, and legumes, that provide key nutrients and protect against noncommunicable disease. Today, most crops receive suboptimal pollination because of limited abundance and diversity of pollinating insects. Animal pollinators are currently suffering owing to a host of direct and indirect anthropogenic pressures: land-use change, intensive farming techniques, harmful pesticides, nutritional stress, and climate change, among others.

OBJECTIVES

We aimed to model the impacts on current global human health from insufficient pollination via diet.

METHODS

We used a climate zonation approach to estimate current yield gaps for animal-pollinated foods and estimated the proportion of the gap attributable to insufficient pollinators based on existing research. We then simulated closing the "pollinator yield gaps" by eliminating the portion of total yield gaps attributable to insufficient pollination. Next, we used an agriculture-economic model to estimate the impacts of closing the pollinator yield gap on food production, interregional trade, and consumption. Finally, we used a comparative risk assessment to estimate the related changes in dietary risks and mortality by country and globally. In addition, we estimated the lost economic value of crop production for three diverse case-study countries: Honduras, Nepal, and Nigeria.

RESULTS

Globally, we calculated that 3%-5% of fruit, vegetable, and nut production is lost due to inadequate pollination, leading to an estimated 427,000 (95% uncertainty interval: 86,000, 691,000) excess deaths annually from lost healthy food consumption and associated diseases. Modeled impacts were unevenly distributed: Lost food production was concentrated in lower-income countries, whereas impacts on food consumption and mortality attributable to insufficient pollination were greater in middle- and high-income countries with higher rates of noncommunicable disease. Furthermore, in our three case-study countries, we calculated the economic value of crop production to be 12%-31% lower than if pollinators were abundant (due to crop production losses of 3%-19%), mainly due to lost fruit and vegetable production.

DISCUSSION

According to our analysis, insufficient populations of pollinators were responsible for large present-day burdens of disease through lost healthy food consumption. In addition, we calculated that low-income countries lost significant income and crop yields from pollinator deficits. These results underscore the urgent need to promote pollinator-friendly practices for both human health and agricultural livelihoods. https://doi.org/10.1289/EHP10947.

Research priorities for global food security under extreme events

Extreme events, such as those caused by climate change, economic or geopolitical shocks, and pest or disease epidemics, threaten global food security. The complexity of causation, as well as the myriad ways that an event, or a sequence of events, creates cascading and systemic impacts, poses significant challenges to food systems research and policy alike. To identify priority food security risks and research opportunities, we asked experts from a range of fields and geographies to describe key threats to global food security over the next two decades and to suggest key research questions and gaps on this topic. Here, we present a prioritization of threats to global food security from extreme events, as well as emerging research questions that highlight the conceptual and practical challenges that exist in designing, adopting, and governing resilient food systems. We hope that these findings help in directing research funding and resources toward food system transformations needed to help society tackle major food system risks and food insecurity under extreme events.

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We asked experts for top threats to global food security from extreme events

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We find unresolved governance challenges underpin many of the key threats

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We also asked experts for top outstanding research priorities on this topic

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Coordination to design, adopt, and govern resilient food systems is needed

Heat waves, floods, droughts, pest outbreaks and diseases, financial crises, and human conflicts are threatening the production and supply of food around the world. These extreme events are on the rise, and our ability to prepare for them seems limited. Multiple events occurring at the same time compound the problem. Research teams and policymakers are developing solutions to improve the resilience of food systems, but this is often done in isolation—tackling one problem at a time. In this article we bring together food system experts to identify the top threats over the next two decades and priority research questions to address them. We find that unresolved governance challenges in international relations underpin many of the key threats and that coordinated research is needed to help design and adopt systems of governance for food systems that are resilient to extreme events in the future.

Exploring connections between pollinator health and human health

Despite recent advances in understanding the role of biodiversity in ecosystem-service provision, the links between the health of ecosystem-service providers and human health remain more uncertain. During the past decade, an increasing number of studies have argued for the positive impacts of healthy pollinator communities (defined as functionally and genetically diverse species assemblages that are sustained over time) on human health. Here, we begin with a systematic review of these impacts, finding only two studies that concomitantly quantified aspects of pollinator health and human health. Next, we identify relevant research relating to four pathways linking pollinator health and human health: nutrition, medicine provisioning, mental health and environmental quality. These benefits are obtained through improved pollination of nutritious crops and an estimated approximately 28 000 animal-pollinated medicinal plants; the provisioning of pollinator-derived products such as honey; the maintenance of green spaces and biocultural landscapes that improve mental health; and cleaner air, water and food resulting from pollinator-centred initiatives to reduce agrochemical use. We suggest that pollinator diversity could be a proxy for the benefits that landscapes provide to human health. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

Bottom-up effects of woodland eutrophication: Interacting limiting nutrients determine herbivory frequency in northwestern Patagonia

Nutrient enrichment disrupts plant-animal interactions and ecosystem functioning globally. In woodland systems, the mechanisms of bottom-up turnover on plant-herbivore interactions remain understudied. Here, we performed a full-factorial field experiment to evaluate the interactive effects of nutrient addition (nitrogen, phosphorus, and/or potassium) on the assemblage of foliar herbivores and the interaction frequency with Berberis microphylla, a dominant shrub species in Patagonian woodlands. Additionally, we assessed whether these effects could be mediated by changes in vegetative traits and microhabitat characteristics (i.e., canopy cover) that may ultimately influence the foraging behavior of herbivores. The addition of nitrogen reduced the herbivory frequency by 41%, yet this effect was diluted in the presence of potassium. We found no effects of phosphorus addition. Our results suggest that the impact of multiple nutrient additions (N and K) on herbivory patterns could be mediated by changes in two important foliar traits, leaf size and leaf density. This study shows how multiple nutrient addition can change the magnitude of antagonistic plant-animal interactions in woodlands. Since herbivory by arthropods has a relevant role in net primary productivity, our results highlight the importance of buffering human-driven woodland eutrophication to maintain important ecological functions (e.g., herbivory) associated with antagonistic plant-animal interactions and avoiding ecosystem dysfunction.

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved.

Opportunities to reduce pollination deficits and address production shortfalls in an important insect-pollinated crop

Pollinators face multiple pressures and there is evidence of populations in decline. As demand for insect-pollinated crops increases, crop production is threatened by shortfalls in pollination services. Understanding the extent of current yield deficits due to pollination and identifying opportunities to protect or improve crop yield and quality through pollination management is therefore of international importance. To explore the extent of "pollination deficits," where maximum yield is not being achieved due to insufficient pollination, we used an extensive dataset on a globally important crop, apples. We quantified how these deficits vary between orchards and countries and we compared "pollinator dependence" across different apple varieties. We found evidence of pollination deficits and, in some cases, risks of overpollination were even apparent for which fruit quality could be reduced by too much pollination. In almost all regions studied we found some orchards performing significantly better than others in terms of avoiding a pollination deficit and crop yield shortfalls due to suboptimal pollination. This represents an opportunity to improve production through better pollinator and crop management. Our findings also demonstrated that pollinator dependence varies considerably between apple varieties in terms of fruit number and fruit quality. We propose that assessments of pollination service and deficits in crops can be used to quantify supply and demand for pollinators and help to target local management to address deficits although crop variety has a strong influence on the role of pollinators.

A global-scale expert assessment of drivers and risks associated with pollinator decline

Pollinator decline has attracted global attention and substantial efforts are underway to respond through national pollinator strategies and action plans. These policy responses require clarity on what is driving pollinator decline and what risks it generates for society in different parts of the world. Using a formal expert elicitation process, we evaluated the relative regional and global importance of eight drivers of pollinator decline and ten consequent risks to human well-being. Our results indicate that global policy responses should focus on reducing pressure from changes in land cover and configuration, land management and pesticides, as these were considered very important drivers in most regions. We quantify how the importance of drivers and risks from pollinator decline, differ among regions. For example, losing access to managed pollinators was considered a serious risk only for people in North America, whereas yield instability in pollinator-dependent crops was classed as a serious or high risk in four regions but only a moderate risk in Europe and North America. Overall, perceived risks were substantially higher in the Global South. Despite extensive research on pollinator decline, our analysis reveals considerable scientific uncertainty about what this means for human society.

Areas Requiring Restoration Efforts are a Complementary Opportunity to Support the Demand for Pollination Services in Brazil

Crop pollination is one of Nature's Contributions to People (NCP) that reconciles biodiversity conservation and agricultural production. NCP benefits vary across space, including among distinct political-administrative levels within nations. Moreover, initiatives to restore ecosystems may enhance NCP provision, such as crop pollination delivered by native pollinators. We mapped crop pollination demand (PD), diversity of pollinator-dependent crops, and vegetation deficit (VD) (vis-a-vis Brazilian legal requirements) across all 5570 municipalities in Brazil. Pollinator-dependent crops represented ∼55% of the annual monetary value of agricultural production and ∼15% of the annual crop production. Municipalities with greater crop PD (i.e., higher degree of pollinator dependence of crop production) also had greater VD, associated with large properties and monocultures. In contrast, municipalities with a greater diversity of pollinator-dependent crops and predominantly small properties presented a smaller VD. Our results support that ecological restoration prompted by legal requirements offers great potential to promote crop productivity in larger properties. Moreover, conservation of vegetation remnants could support food security in small properties. We provided the first steps to identify spatial patterns linking biodiversity conservation and pollination service. Using Brazilian legal requirements as an example, we show that land-use management policies may be successfully used to ensure agricultural sustainability and crop production.

Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong "numerical" effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative "identity" effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.

Temporal Trends in Pollination Deficits and Its Potential Impacts on Chinese Agriculture

Worldwide, there is increasing evidence that shows a decline in pollinators, limiting crop pollination and production. However, it is unclear to what extent Chinese agriculture could be impacted by pollinator deficits. Data for 84 major crops in China between 1961 and 2018 were analyzed for the temporal trends in crop area and production, agricultural economic contribution of pollination, crop yield deficits, and honey bee pollination demand. We found a rapid increase in agricultural dependence on insect pollinators: both the cultivated area and total production of pollinator-dependent crops increased faster than those of pollinator-independent crops during 1961-2018. The total economic value of pollination amounted to US$ 106.08 billion in 2010, representing 19.12% of the total production value of Chinese agriculture, approximately twice the 9.5% value estimated for global agriculture. Crops with higher pollinator dependence showed greater mean growth in cultivated area than those with lower dependence, but lower mean growth of crop production and yield. Crop yield growth was also more unstable with increasing pollinator dependence. The minimum pollination demand for honey bee colonies was about three times the stock of honey bee colonies available in 2018. Furthermore, we found a decline in crop yield deficit with the increase in honey bee colony pollination service capacity. We considered that the shortage of pollinators resulted in the yield deficits for pollinator-dependent crops. Future increase in the area of pollinator-dependent crops will increase the need for more pollinators, suggesting the importance of implementing measures to protect pollinators to ensure a better-secured future for agricultural production in China.

Building effective policies to conserve pollinators: translating knowledge into policy

Pollination management recommendations are becoming increasingly precise, context-specific and knowledge-intensive. Pollination is a service delivered across landscapes, entailing policy constructs across agricultural landscapes. Diversified farming practices effectively promote pollination services. Yet it remains difficult to secure large-scale uptake by farming communities. A strong foundation upon which to base policy formulation stems from respecting the perspective of farmers and local communities on the need to conserve pollinators, alongside scientific understanding. Ecological intensification resonates with both indigenous knowledge, local communities and scientific understanding. It emphasizes that the regulating functions of nature require both landscape-level agroecosystem design and recognition of the complexity of agricultural systems. Facilitating ecological intensification across landscapes requires collective decision-making, with institutional innovation in local structures and food system governance.

Time to Integrate Pollinator Science into Soybean Production

Soybeans cover 129 million hectares globally. Soybean productivity can increase with pollinator management, but soybean cultivation practices commonly ignore biotic pollination. If pollinator habitats are created within soybean landscapes and policies to limit agricultural expansion are implemented, millions of hectares could be restored for biodiversity without loss of soybean production.

Wild insect diversity increases inter-annual stability in global crop pollinator communities

While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three-most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognizing wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilizing pollination services need to be considered alongside longer term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability.

Agroecology in Large Scale Farming—A Research Agenda

Agroecology promises a third way between common global agriculture tradeoffs such as food production and nature conservation, environmental sustainability and ecosystem services. However, most successful examples of mainstreaming agroecology come from smallholder, family agriculture, that represents only about 30% of the world agricultural area. Mainstreaming agroecology among large scale farmers is urgently needed, but it requires addressing specific questions in research, technology and policy development to support sustainable transitions. Here we take stock of the existing knowledge on some key aspects necessary to support agroecological transitions in large scale farming, considering two contrasting starting points: highly subsidized and heavily taxed agricultural contexts, represented here by the examples of Western Europe and temperate South America. We summarize existing knowledge and gaps around service crops, arthropod-mediated functions, landscape and watershed regulation, graze-based livestock, nature-inclusive landscapes, and policy mechanisms to support transitions. We propose a research agenda for agroecology in large scale farming organized in five domains: (i) Breeding for diversity, (ii) Scalable complexity, (iii) Managing cycles beyond fields and farms, (iv) Sharing the cultivated landscape, and (v) Co-innovation with farmers, value chains and policy makers. Agroecology may result in a renewed impetus in large scale farming, to attract the youth, foster clean technological innovation, and to promote a new generation of large-scale farmers that take pride in contributing to feeding the world while serving the planet and its people.

Insect Pollination, More than Plant Nutrition, Determines Yield Quantity and Quality in Apple and Pear

Agricultural yield is the result of multiple factors and ecological processes (e.g., pollination, fertilization, pest control). Understanding how the different factors interact is fundamental to designing management practices aimed to increase these yields, which are environmental friendly and sustainable over time. In this study, we focus on insect pollination and plant nutrition status, since they are two key factors that influence crop yield. The study was carried out in Northwest Patagonia Argentina, which is an area of intensive production of pears and apples of global importance, during the harvest seasons 2018 and 2019. The plant nutrition was estimated from leaf chlorophyll content. Biotic pollination benefits were evaluated by comparing fruit quantity (fruit to flower ratio) and quality (weight, size, and sugar concentration) from approximately 25 flowers exposed to pollinators and 25 flowers excluded to them per tree (a total of 160 apple trees and 130 pear trees). In addition, we estimated the visitation rate of pollinators to flowers and related it to fruit quality in apple. Despite different floral characteristics, we found in both crops a positive effect of insect pollination in both the quantity and the quality of the fruits. Interestingly, the nutrition of the trees, although variable, did not affect either the quantity or the quality of the fruits. Despite the weak effect of nutrition, we found no interaction between pollination and plant nutrition (i.e., additive effects). These results highlight the importance of agricultural practices that promote pollinators on farms.

Impact of Invasive Bees on Plant-Pollinator Interactions and Reproductive Success of Plant Species in Mixed Nothofagus antarctica Forests

Invasive social bees can alter plant-pollinator interactions with detrimental effects on both partners. However, most studies have focused on one invasive bee species, while the interactions among two or more species remain poorly understood. Also, many study sites had a history of invasive bees, being hard to find sites with historical low abundances. In Patagonia, Bombus ruderatus (F.) invasion begun in 1993 and B. terrestris (L.) in 2006. Though honey bees (Apis mellifera L.) introduction started in 1859, their density is still low in some parts. By experimentally increasing honey bee densities, we evaluated the effect of honey bees and bumblebees floral visitation on native pollinator floral visitation, pollen deposition, and reproductive success of three plant species in mixed Nothofagus antarctica forests of northern Patagonia: Oxalis valdiviensis, Mutisia spinosa and Cirsium vulgare. Our results show that exotic bees became the main floral visitors. No negative association was found between invasive bee and native pollinator visitation rates, but there was evidence of potential competition between honey bees and bumblebees. Floral neighborhood diversity played an important role in pollinator behavior. Conspecific pollen deposition was high for all species, while deposition of heterospecific pollen was very high in M. spinosa and C. vulgare. Not as expected, honey bees visitation rate had a negative effect on heterospecific pollen deposition in C. vulgare. For O. valdiviensis, exotic visitation rates increased conspecific pollen deposition, which was positively related to reproductive success. Although exotic bees became main floral visitors, their contribution to reproductive success was only clear for one species.

Short-term responses to sheep grazing in a Patagonian steppe

Grazing modifies ecosystem function through direct effects on plants, but also through indirect effects mediated by floristic changes induced by grazing. Although both types of effects occur in the long term, only the direct effects are evident in the short term. We evaluated the short-term direct effects of sheep (Ovis aries) grazing on a Patagonian steppe during one growing season. We measured plant aerial cover in permanent transects located at increasing distances from a watering point in three paddocks with different stocking rates through the growing season. We also measured frequency of defoliation for vegetative and reproductive phases of different plant species located along these transects. Sheep grazing directly (a) reduced aerial cover and/or increased frequency of defoliation of certain preferred grasses and perennial forbs, (b) did not increase the aerial cover of any life form, but only the proportion of bare soil, (c) did not change the litter aerial cover, and (d) defoliated the flowers of even the least preferred shrub. Result a) was coincident with previous plant aerial cover long-term studies; but results (b) and (c) were contrary to long-term studies, probably because they resulted from indirect rather than direct grazing effects. Result (d) was not detected by long-term studies, probably because flower defoliation through grazing is undetectable when measuring shrub plant aerial cover. Our study showed that grazing has short-term direct effects mainly on the most preferred species. This could be useful for rangeland management and conservation of Patagonian steppes because short-term effects may be more easily reversible than long-term ones, and may provide early warning of rangeland condition deterioration.

Pervasive human-driven decline of life on Earth points to the need for transformative change

The human impact on life on Earth has increased sharply since the 1970s, driven by the demands of a growing population with rising average per capita income. Nature is currently supplying more materials than ever before, but this has come at the high cost of unprecedented global declines in the extent and integrity of ecosystems, distinctness of local ecological communities, abundance and number of wild species, and the number of local domesticated varieties. Such changes reduce vital benefits that people receive from nature and threaten the quality of life of future generations. Both the benefits of an expanding economy and the costs of reducing nature's benefits are unequally distributed. The fabric of life on which we all depend-nature and its contributions to people-is unravelling rapidly. Despite the severity of the threats and lack of enough progress in tackling them to date, opportunities exist to change future trajectories through transformative action. Such action must begin immediately, however, and address the root economic, social, and technological causes of nature's deterioration.

Pervasive human-driven decline of life on Earth points to the need for transformative change

The human impact on life on Earth has increased sharply since the 1970s, driven by the demands of a growing population with rising average per capita income. Nature is currently supplying more materials than ever before, but this has come at the high cost of unprecedented global declines in the extent and integrity of ecosystems, distinctness of local ecological communities, abundance and number of wild species, and the number of local domesticated varieties. Such changes reduce vital benefits that people receive from nature and threaten the quality of life of future generations. Both the benefits of an expanding economy and the costs of reducing nature's benefits are unequally distributed. The fabric of life on which we all depend-nature and its contributions to people-is unravelling rapidly. Despite the severity of the threats and lack of enough progress in tackling them to date, opportunities exist to change future trajectories through transformative action. Such action must begin immediately, however, and address the root economic, social, and technological causes of nature's deterioration.

Pervasive human-driven decline of life on Earth points to the need for transformative change

The human impact on life on Earth has increased sharply since the 1970s, driven by the demands of a growing population with rising average per capita income. Nature is currently supplying more materials than ever before, but this has come at the high cost of unprecedented global declines in the extent and integrity of ecosystems, distinctness of local ecological communities, abundance and number of wild species, and the number of local domesticated varieties. Such changes reduce vital benefits that people receive from nature and threaten the quality of life of future generations. Both the benefits of an expanding economy and the costs of reducing nature’s benefits are unequally distributed. The fabric of life on which we all depend—nature and its contributions to people—is unravelling rapidly. Despite the severity of the threats and lack of enough progress in tackling them to date, opportunities exist to change future trajectories through transformative action. Such action must begin immediately, however, and address the root economic, social, and technological causes of nature’s deterioration.

Global agricultural productivity is threatened by increasing pollinator dependence without a parallel increase in crop diversification

The global increase in the proportion of land cultivated with pollinator-dependent crops implies increased reliance on pollination services. Yet agricultural practices themselves can profoundly affect pollinator supply and pollination. Extensive monocultures are associated with a limited pollinator supply and reduced pollination, whereas agricultural diversification can enhance both. Therefore, areas where agricultural diversity has increased, or at least been maintained, may better sustain high and more stable productivity of pollinator-dependent crops. Given that >80% of all crops depend, to varying extents, on insect pollination, a global increase in agricultural pollinator dependence over recent decades might have led to a concomitant increase in agricultural diversification. We evaluated whether an increase in the area of pollinator-dependent crops has indeed been associated with an increase in agricultural diversity, measured here as crop diversity, at the global, regional, and country scales for the period 1961-2016. Globally, results show a relatively weak and decelerating rise in agricultural diversity over time that was largely decoupled from the strong and continually increasing trend in agricultural dependency on pollinators. At regional and country levels, there was no consistent relationship between temporal changes in pollinator dependence and crop diversification. Instead, our results show heterogeneous responses in which increasing pollinator dependence for some countries and regions has been associated with either an increase or a decrease in agricultural diversity. Particularly worrisome is a rapid expansion of pollinator-dependent oilseed crops in several countries of the Americas and Asia that has resulted in a decrease in agricultural diversity. In these regions, reliance on pollinators is increasing, yet agricultural practices that undermine pollination services are expanding. Our analysis has thereby identified world regions of particular concern where environmentally damaging practices associated with large-scale, industrial agriculture threaten key ecosystem services that underlie productivity, in addition to other benefits provided by biodiversity.

A global synthesis reveals biodiversity-mediated benefits for crop production

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.

A nonlinear mixed-effects modeling approach for ecological data: Using temporal dynamics of vegetation moisture as an example

Increasingly, often ecologist collects data with nonlinear trends, heterogeneous variances, temporal correlation, and hierarchical structure. Nonlinear mixed-effects models offer a flexible approach to such data, but the estimation and interpretation of these models present challenges, partly associated with the lack of worked examples in the ecological literature.We illustrate the nonlinear mixed-effects modeling approach using temporal dynamics of vegetation moisture with field data from northwestern Patagonia. This is a Mediterranean-type climate region where modeling temporal changes in live fuel moisture content are conceptually relevant (ecological theory) and have practical implications (fire management). We used this approach to answer whether moisture dynamics varies among functional groups and aridity conditions, and compared it with other simpler statistical models. The modeling process is set out "step-by-step": We start translating the ideas about the system dynamics to a statistical model, which is made increasingly complex in order to include different sources of variability and correlation structures. We provide guidelines and R scripts (including a new self-starting function) that make data analyses reproducible. We also explain how to extract the parameter estimates from the R output.Our modeling approach suggests moisture dynamic to vary between grasses and shrubs, and between grasses facing different aridity conditions. Compared to more classical models, the nonlinear mixed-effects model showed greater goodness of fit and met statistical assumptions. While the mixed-effects approach accounts for spatial nesting, temporal dependence, and variance heterogeneity; the nonlinear function allowed to model the seasonal pattern.Parameters of the nonlinear mixed-effects model reflected relevant ecological processes. From an applied perspective, the model could forecast the time when fuel moisture becomes critical to fire occurrence. Due to the lack of worked examples for nonlinear mixed-effects models in the literature, our modeling approach could be useful to diverse ecologists dealing with complex data.

The interplay of landscape composition and configuration: new pathways to manage functional biodiversity and agroecosystem services across Europe

Managing agricultural landscapes to support biodiversity and ecosystem services is a key aim of a sustainable agriculture. However, how the spatial arrangement of crop fields and other habitats in landscapes impacts arthropods and their functions is poorly known. Synthesising data from 49 studies (1515 landscapes) across Europe, we examined effects of landscape composition (% habitats) and configuration (edge density) on arthropods in fields and their margins, pest control, pollination and yields. Configuration effects interacted with the proportions of crop and non-crop habitats, and species' dietary, dispersal and overwintering traits led to contrasting responses to landscape variables. Overall, however, in landscapes with high edge density, 70% of pollinator and 44% of natural enemy species reached highest abundances and pollination and pest control improved 1.7- and 1.4-fold respectively. Arable-dominated landscapes with high edge densities achieved high yields. This suggests that enhancing edge density in European agroecosystems can promote functional biodiversity and yield-enhancing ecosystem services.