Forecasting agriculturally driven global environmental change.

Phosphorus (P) is an essential macronutrient for all living organisms. It serves various basic biological functions as a structural element in nucleic acids and phospholipids, in energy metabolism, in the activation of metabolic intermediates, as a component in signal transduction cascades, and the regulation of enzymes. Of the major nutrients, P is the most dilute and the least mobile in soil. High sorbing capacity for P in the soil (e.g. sorbtion to metal oxides), P mineralization (e.g. calcium phosphates such as apatite), and/or fixation of P in organic soil matter (by converting soluble P into organic molecules) result in low availability of this macronutrient for uptake into plants (Marschner, 1995). P is absorbed by plants as orthophosphate (Pi, inorganic phosphate). Pi concentration in the soil solution hardly reaches 10 µM and may even drop to submicromolar levels at the root/soil interface, where Pi uptake by plants and root surface-colonizing microorganisms leads to the generation of a zone of Pi depletion around the root cylinder that is maintained due to slow diffusion of Pi from regions distant to the root surface (Figure 1). Fig. 1. A transverse section through the tip of a primary root. The dotted line indicates the outer border of the P depletion zone. The arrow indicates the direction of growth. In industrialized countries, low P availability in agricultural soils is compensated by a high input of P fertilizer to guarantee high crop productivity and yield. Water run-off, soil erosion and leakage in highly fertilized agricultural soils may cause environmental problems such as eutrophication of lakes and rivers. As forecasted by Tilman et al. (2001), during the next 50 years, which is likely to be the final period of rapid agricultural expansion, demand for food by global population will be a major driver of global environmental change. Conversion of natural ecosystems to agriculture by 2050 will be accompanied by an approximate 2.5-fold increase in nitrogen- and P- driven eutrophication of terrestrial, freshwater, and near-shore marine ecosystems. Modern agricultural soils are almost universally maintained at high fertilization. Selection of new cultivars is usually made under such conditions and will not normally distinguish between plants varying in nutrient efficiency (Stevens and Rick, 1986). To alleviate the forecasted adverse negative effects of agricultural expansion, scientists have started to use classical breeding strategies and biotechnology to improve crop plants, based on the current knowledge and aiming at an improved crop yield with a lower input of fertilizer, thus protecting the environment. In contrast, in many developing tropical countries, subsistence farmers can not buy enough fertilizer due to limited financial capacities or poor infrastructure (Sanchez et al., 1997). As a consequence, P deprivation dramatically limits crop yield and is one of the reasons for poverty and malnutrition. In the future, agriculture from both developed as well as developing countries could thus benefit from modern crop varieties with enhanced P efficiency, thus leading to improved fertilizer management and increased crop yield on low-P soils. Thorough knowledge of the plant's response to P deprivation stress will contribute to the rational and targeted breeding of P efficient crop plants. Therefore, the authors of this chapter focus on summarizing the current state of research covering physiology, biochemistry, and molecular genetics of P acquisition and allocation, and P homeostasis within the plant. Although this review will mainly focus on knowledge acquired on Arabidopsis thaliana, some specific results obtained with other plant species will also be included in this work. For example, formation of mycorrhizae, which is observed in most vascular plants and strongly contributes to plant P nutrition, does not occur in Brassicaceae and therefore Arabidopsis is not a suitable model for mycorrhizae studies.

Agriculture is nowadays the largest driver of global environmental change, with modern agricultural systems being a primary cause of biodiversity loss, including bird declines. Agricultural intensification affects bird populations through both a reduction in landscape heterogeneity and an increase in the use of pesticides, which negatively influences a variety of bird species. The objective of this chapter is to examine how agricultural intensification and the associated increase in pesticide use can affect farmland birds. Special attention is given to the case of pesticide-treated seeds, and the current guidelines on how to perform the risk assessment of seed treatments are explained. Nevertheless, because a number of registered pesticide seed treatments have been found to pose a risk to farmland birds, current regulatory risk assessment protocols need to be improved so as to provide more accurate predictions of real-life situations and to better protect bird populations.

Non‐structural carbohydrates (NSCs, including soluble sugars and starch) are essential to support the growth and survival of terrestrial plants. Starch and sugars play different roles in multiple plant ecological functions such as drought tolerance, growth and plant defence, and several other processes which are being rapidly shaped by global environmental change. However, it is uncertain whether soluble sugars and starch show different responses across plant functional types, tissue types and treatment conditions (i.e. the intensity and duration of environmental variability) to global‐change drivers.Here based on a database of 275 plants (including 17 plant functional types), we conducted a meta‐analysis to examine the effects of elevated atmospheric CO2concentration (eCO2), nitrogen (N) addition, drought and warming on NSCs and its components.We found NSCs responses to global environmental change were mainly driven by (a) soluble sugar changes in response to N addition and drought, as well as (b) starch changes in response to eCO2and warming. The different responses between soluble sugars and starch were more evident under eCO2and drought, especially in herbs or leaves. Interactive effects of multiple environmental change drivers on soluble sugars and starch were mainly additive. The divergent main and interactive effects on soluble sugars and starch depend on experimental conditions. For example, the starch responses to eCO2and its interaction with N addition were the strongest in short‐term experiments.Overall, our study shows the divergent responses of soluble sugars and starch in terrestrial plants to different global environmental change drivers, suggesting a changed carbon sink–source balance in plants under future global changes. The findings also highlight that predicting plant functional changes into the future requires a mechanistic understanding of how NSCs and its components are linked to specific environmental change drivers.A freePlain Language Summarycan be found within the Supporting Information of this article.

The present study examines pesticide use in producing multiple food crops (i.e., rice, yam, and cassava) and identifies the range of socio-economic factors influencing pesticide use by 400 farmers from Ebonyi and Anambra states of Southeastern Nigeria using a Tobit model. Results reveal that 68% of the farmers grew at least two food crops. Overall, 41% of the farmers applied pesticides in at least one food crop, whereas 70% of the farmers producing both rice and yam applied pesticides. Pesticide use rates and costs vary significantly amongst farmers producing different food crops and crop combinations. Pesticide use rate is highest for producing yam followed by cassava estimated at 1.52 L/ha costing Naira 1677.97 per ha and 1.37 L/ha costing Naira 1514.96 per ha. Similarly, pesticide use rate is highest for the farmers that produce both yam and cassava followed by farmers that produce both rice and cassava. The inverse farm size–pesticide use rate exists in the study areas, i.e., the pesticide use rate is highest for the small farmers (p < 0.01). Farmers seem to treat pesticides as substitutes for labor and ploughing services, indicated by the significant positive influence of labor wage and ploughing price on pesticide use. Increases in yam price significantly increase pesticide use. Rice production significantly increases pesticide use, whereas cassava production significantly reduces pesticide use. Male farmers use significantly more pesticides. Farming experience is significantly positively related to pesticide use. Policy recommendations include land reform policies aimed at increasing farm operation size and investment in programmes to promote cassava production to reduce pesticide use in food crop production in Southeastern Nigeria.

Genetically modified (GM) crops were officially authorized in Brazil in 2003. In this documentary study, we aimed to identify possible changes in the patterns of pesticide use after the adoption of this technology over a span of 13 years (2000 to 2012). The following variables were analyzed: Pesticide use (kg), Pesticide use per capita (kg/inhab), Pesticide and herbicide use per area (kg/ha) and productivity (kg/ha). Contrary to the initial expectations of decreasing pesticide use following the adoption of GM crops, overall pesticide use in Brazil increased 1.6-fold between the years 2000 and 2012. During the same period, pesticide use for soybean increased 3-fold. This study shows that the adoption of GM crops in Brazil has led to an increase in pesticide use with possible increases in environmental and human exposure and associated negative impacts.

Consumption, human needs, and global environmental change

Current global change substantially threatens pollinators, which directly impacts the pollination services underpinning the stability, structure and functioning of ecosystems. Amongst these threats, many synergistic drivers, such as habitat destruction and fragmentation, increasing use of agrochemicals, decreasing resource diversity, as well as climate change, are known to affect wild and managed bees. Therefore, reliable indicators for pollinator sensitivity to such threats are needed. Biological traits, such as phenotype (e.g. shape, size and asymmetry) and storage reserves (e.g. fat body size), are important pollinator traits linked to reproductive success, immunity, resilience and foraging efficiency and, therefore, could serve as valuable markers of bee health and pollination service potential. This data paper contains an extensive dataset of wing morphology and fat body content for the European honeybee (Apis mellifera) and the buff-tailed bumblebee (Bombus terrestris) sampled at 128 sites across eight European countries in landscape gradients dominated by two major bee-pollinated crops (apple and oilseed rape), before and after focal crop bloom and potential pesticide exposure. The dataset also includes environmental metrics of each sampling site, namely landscape structure and pesticide use. The data offer the opportunity to test whether variation in the phenotype and fat bodies of bees is structured by environmental factors and drivers of global change. Overall, the dataset provides valuable information to identify which environmental threats predominantly contribute to the modification of these traits.

While pesticides are essential to agriculture and food systems to sustain current production levels, they also lead to significant environmental impacts. The use of pesticides is constantly increasing globally, driven mainly by a further intensification of agriculture, despite stricter regulations and higher pesticide effectiveness. To further the understanding of future pesticide use and make informed farm-to-policy decisions, we developed Pesticide Agricultural Shared Socio-economic Pathways (Pest-AgriSSPs) in six steps. The Pest-Agri-SSPs are developed based on an extensive literature review and expert feedback approach considering significant climate and socio-economic drivers from farm to continental scale in combination with multiple actors impacting them. In literature, pesticide use is associated with farmer behaviour and practices, pest damage, technique and efficiency of pesticide application, agricultural policy and agriculture demand and production. Here, we developed PestAgri-SSPs upon this understanding of pesticide use drivers and relating them to possible agriculture development as described by the Shared Socio-economic Pathways for European agriculture and food systems (Eur-Agri-SSPs).The Pest-AgriSSPs are developed to explore European pesticide use in five scenarios representing low to high challenges to mitigation and adaptation up to 2050. The most sustainable scenario (Pest-Agri-SSP1) shows a decrease in pesticide use owing to sustainable agricultural practices, technological advances and better implementation of agricultural policies. On the contrary, the Pest-Agri-SSP3 and Pest-Agri-SSP4 show a higher increase in pesticide use resulting from higher challenges from pest pressure, resource depletion and relaxed agricultural policies. Pest-Agri-SSP2 presents a stabilised pesticide use resulting from stricter policies and slow transitions by farmers to sustainable agricultural practices. At the same time, pest pressure, climate change and food demand pose serious challenges. Pest-Agri-SSP5 shows a decrease in pesticide use for most drivers, influenced mainly by rapid technological development and sustainable agricultural practices. However, Pest-Agri-SSP5 also presents a relatively low rise in pesticide use driven by agricultural demand, production, and climate change. Our results highlight the need for a holistic approach to tackle pesticide use, considering the identified drivers and future developments. The storylines and qualitative assessment provide a platform to make quantitative assumptions for numerical modelling and evaluating policy targets.

The rationale for pesticide use in agriculture is that costs associated with pesticide pollution are to be justified by its benefits, but this is not so obvious. Valuing the benefits by simple economic analysis has increased pesticide use in agriculture and consequently produced pesticide-induced “public ills.” This paper attempts to explore the research gaps of the economic and social consequences of pesticide use in developing countries, particularly with an example of Nepal. We argue that although the negative sides of agricultural development, for example- soil, water, and air pollution; pest resistance and resurgence; bioaccumulation, bio-magnification; and loss of biodiversity and ecosystem resilience caused by the use of pesticides in agriculture, are “developmental problems” and are “unintentional,” the magnitude may be increased by undervaluing the problems in the analysis of its economic returns. Despite continuous effort for holistic system analyses for studying complex phenomena like pesticides impacts, the development within the academic science has proceeded in the opposite direction that might have accelerated marginalization of the third world subsistence agricultural communities. We hypothesize that, if these adversities are realized and accounted for, the benefits from the current use of pesticides could be outweighed by the costs of pollution and ill human health. This paper also illustrates different pathways and mechanisms for marginalization. In view of potential and overall negative impacts of pesticide use, we recommend alternative ways of controlling pests such as community integrated pest management (IPM) along with education and training activities. Such measures are likely to reduce the health and environmental costs of pesticide pollution, and also enhance the capabilities of third world agricultural communities in terms of knowledge, decision making, innovation, and policy change.

Standard tools that can quantitatively track the impacts of higher global demand for animal-sourced food to their local environmental effects in developing countries are largely missing. This paper presents a novel integrated assessment framework that links a model of the global agricultural and food system, a landscape-level environmental impact assessment model, and an ecosystem services simulation model. For Tanzania, this integrated assessment showed that a projected increase in the demand and production of foods of livestock origin with optimistic economic growth between 2010 and 2030 leads to an improvement in food security. However, resulting transitions in land use impact negatively on the future provisioning of ecosystem services, increasing phosphorus, nitrogen, and sediment in runoff and reducing water quality in areas downstream of the agricultural expansion. Losses in ecosystem services are lowest when diversified farming practices are adopted in areas of agricultural land expansion. The role of land management in the environmental impacts of expanded livestock production is highlighted, as is the need for a new generation of analytical tools to inform policy recommendations.

Global environmental change is expected to dramatically affect agricultural crop production through a myriad of pathways. One important and thus far poorly understood impact is the effect of land cover and climate change on agricultural insect pests and insecticides. Here we address the following three questions: (1) how do landscape complexity and weather influence present-day insecticide use, (2) how will changing landscape characteristics and changing climate influence future insecticide use, and how do these effects manifest for different climate and land cover projections? and (3) what are the most important drivers of changing insecticide use? We use panel models applied to county-level agriculture, land cover, and weather data in the US to understand how landscape composition and configuration, weather, and farm characteristics impact present-day insecticide use. We then leverage forecasted changes in land cover and climate under different future scenarios to predict insecticide use in 2050. We find different future scenarios—through modifications in both landscape and climate conditions—increase the amount of area treated by ~ 4–20% relative to 2017, with regionally heterogeneous impacts. Of note, we report large farms are more influential than large crop patches and increased winter minimum temperature is more influential than increased summer maximum temperature. However, our results suggest the most important determinants of future insecticide use are crop composition and farm size, variables for which future forecasts are sparse. Both landscape and climate change are expected to increase future insecticide use. Yet, crop composition and farm size are highly influential, data-poor variables. Better understanding of future crop composition and farm economics is necessary to effectively predict and mitigate increases in pesticide use.

Pesticide use is a crucial human-driven change in the Anthropocene that negatively impacts the environment and ecosystems. While pesticides are essential to agriculture to sustain crop production and ensure global food security, they also lead to significant environmental impacts. The export of pesticides after application from the agricultural fields threatens the soil, groundwater and surface water quality in many world regions. Pesticide use is constantly increasing globally, driven mainly by agricultural intensification, despite stricter regulations and higher pesticide effectiveness. To enhance the understanding of future pesticide use and emissions and make informed farm-to-policy decisions, we developed Pesticide Agricultural Shared Socio-Economic Pathways (Pest-Agri-SSPs) in six steps. The Pest-Agri-SSPs are based on an extensive literature review and expert knowledge, considering significant climate and socio-economic drivers from farm to continental scale in combination with multiple actors impacting them. In the literature, pesticide use is associated with farmer behaviour and agricultural practices, pest damage, technique and efficiency of pesticide application, agricultural policy and demand for agricultural products. Here, we developed Pest-Agri-SSPs upon this understanding of pesticide use drivers and relating them to plausible sectoral developments, as described by the Shared Socio-economic Pathways for European agriculture and food systems (Eur-Agri-SSPs). The Pest-Agri-SSPs present European pesticide use in five scenarios with low to high challenges to climate change adaptation and mitigation up to 2050. The most sustainable scenario (Pest-Agri-SSP1) shows a decrease in pesticide use owing to sustainable agricultural practices, technological advances and a pro-environmental orientation of agricultural policies. On the contrary, the Pest-Agri-SSP3 and Pest-Agri-SSP4 show an increase in pesticide use resulting from high challenges from pest pressure, resource depletion and relaxed agricultural policies. Pest-Agri-SSP2 presents a stabilised pesticide use resulting from strict policies and slow transitions by farmers to sustainable agricultural practices. Pest-Agri-SSP5 shows a decrease in pesticide use for most drivers, influenced mainly by rapid technological development and the application of sustainable agricultural practices. However, Pest-Agri-SSP5 also shows a relatively low rise in pesticide use driven by agricultural demand, production, and climate change. Our results highlight the need for a holistic approach to tackle pesticide use and emissions, considering the identified drivers and future developments. The storylines and qualitative assessment provide a platform to make quantitative assumptions for numerical modelling and evaluating policy targets. Keywords: Farm characteristics, pest damage, technology, policy, socioeconomic, agriculture and food systems Adapted version of this work has been submitted to Journal of Environmental Management: Nagesh P, Edelenbosch OY , Dekker SC, de Boer HJ, Mitter H, van Vuuren DP. Pesticide use under the influence of socio-economic and climate change: Pest-Agri-SSPs    

The major drivers of global environmental change, and which affect biodiversity, include habitat loss and alteration, invasive alien species, pollution, and climate change. The catalyst for much of today’s insect ecology and conservation research is rapid global environmental change, combined with the recognized importance and functional significance of insect biodiversity. In the context of global change, insects are studied to understand (1) the impact of environmental change on insect biodiversity, and (2) the consequences of a change in insect biodiversity on overall biodiversity and ecosystem functioning as we know it, as well as (3) to examine the possibility of using insects to provide some sort of early warning system or indication of the extent, rate, and nature of environmental change.

The use of synthetic organic pesticides in US agriculture grew dramatically from the late 1940s until the early 1980s, stabilized in the 1980s, and increased at a much slower rate through the 1990s. The extent of pesticide use responded to market factors, such as price trends, which affected crop acreage and encouraged use of more cost‐effective inputs, but also to farm programs. The development of genetically modified crops, if accepted by consumers and regulators, may influence future pesticide use trends, crop yields, and pest control costs. Increased pesticide use led to concerns about counterproductive effects on pest control, such as increased pest resistance. Scientists developed the concepts of integrated pest management (IPM) and economic thresholds to eliminate unnecessary pesticide applications and encourage nonpesticide practices where economically feasible. Increased pesticide use also led to controversies about food safety, water quality, worker safety, and wildlife mortality. These concerns, and changing societal attitudes emerging in the 1960s, resulted in a series of laws, including the Food Quality Protection Act of 1996, that changed the regulatory process to emphasize protection from pesticide hazards. The regulatory process affects pesticide use by influencing the development of pesticides, registering new materials, and removing others from the market.

In the context of increasing global environmental changes, it has become progressively important to understand the effects of human activity on wildlife populations. Declines in several avian populations have been observed since the 1970s, especially with respect to many farmland and grassland birds, which also include some aerial insectivores. Changes in farming practices referred to as agricultural intensification coincide with these major avian declines. Among those practices, increased pesticide use is hypothesized to be a key driver of avian population declines as it can lead to both toxicological and trophic effects. While numerous laboratory studies report that birds experience acute and chronic effects upon consuming pesticide treated food, little is known about the effects of the exposure to multiple pesticides on wildlife in natural settings. We monitored the breeding activities of Tree Swallows (Tachycineta bicolor) on 40 farms distributed over a gradient of agricultural intensification in southern Québec, Canada, to evaluate the presence of pesticides in their diet and quantify the exposure effects of those compounds on their reproductive performance between 2013 and 2018. We first assessed the presence of 54 active agents (or derivatives) found in pesticides in 2,081 food boluses (insects) delivered to nestlings by parents and documented their spatial distribution within our study area. Second, we assessed the effect of pesticide exposure through food (number of active agents detected and number of contaminated boluses on a given farm for a given year, while controlling for sampling effort) on clutch size as well as hatching and fledging successes and nestling's mass upon fledging. Pesticides were ubiquitous in our study system and nearly half (46%) of food boluses were contaminated by at least one active agent. Yet we found no relationship between our proxies of food contamination by pesticides and Tree Swallow reproductive performance. More studies are needed to better understand the putative role of pesticides in the decline of farmland birds and aerial insectivores as potential sublethal effects of pesticides can carry over to later life stages and impact fitness.