Assessing the economic impact of insect pollination on the agricultural sector: A department-level case study in France.

Assessing the economic impact of insect pollination on the agricultural sector: A department-level case study in France Yasmine Blili a,b , Elie Abou Nader a , Iciar Pavez a , Paolo Prosperi a , Rachid Harbouze a,b , Leonidas Sotirios Kyrgiakos d , Christina Kleisiari d , Marios Vasileiou d , Vasileios Angelopoulos d , George Vlontzos d , Georgios Kleftodimos a,c,* a CIHEAM-IAMM - Mediterranean Agronomic Institute of Montpellier, Montpellier, 34090, France b IAV Hassan II – Hassan II Institute of Agronomy and Veterinary Sciences, BP, Rabat, 6202, Morocco c UMR MoISA, Univ Montpellier, CIHEAM-IAMM, CIRAD, INRAE, Institut Agro, IRD, Montpellier, 34090, France d Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Fytoko, Volos, 38446, Greece ARTICLE INFO Keywords: Pollinators Economic value Vulnerability ratio Dependence ratio method Agriculture Policy ABSTRACT Pollination is a critical ecosystem service for agriculture, with 76 % of European food crops and 80 % of wild plants depending on it. However, bee populations are declining due to diseases, pesticides, and climate change, with major economic and environmental impacts. In France, pollination services are valued between 2,3 and 5,3 billion euros annually, but detailed data at the department scale (NUTS 3) is lacking. This study aims to fill this gap by quantifying the economic value of crop production (EVCP), the economic value of insect pollination (EVIP), and agricultural vulnerability to pollinator loss across all French departments. We analyzed data from 2022 for 34 major crops, of which 26 are pollinator-dependent, applying the dependence ratio method to estimate pollination contributions. We also developed a generalized additive model (GAM) to identify the main drivers of spatial variation in EVIP per hectare. We estimate France’s economic value of crop production at 34,8 billion € and economic value of insect pollination at 4,2 billion € , with an agricultural vulnerability rate of 12 %. The highest economic value of insect pollination per hectare was recorded in Loire-Atlantique (19302,5 € /ha) and the lowest in Seine-Saint-Denis (575,5 € /ha). By analyzing crop-specific dependencies and regional production patterns, the study reveals that southern and western France, particularly departments specialized in fruit and vegetables, are most economically dependent and vulnerable to pollinator decline. The GAM explained 97.6 % of the variability in EVIP per hectare, revealing that fruit and vegetable cultivation strongly drives pollination value. The results highlight spatial disparities in pollination dependency and underscore the need for territorially targeted conservation strategies. Compared to previous studies, our findings suggest a significant underestimation of pollination value, highlighting the need for fine-scale entomological research and territorially targeted conservation strategies to support sustainable agricultural development. However, the study has some limitations: certain crop prices had to be approximated, dependence ratios were fixed and do not account for local ecological conditions, and some minor crops were excluded. Despite these constraints, the results remain robust and provide a reliable basis for territorialized conservation policies. 1. Introduction Pollination is a vital ecological process that ensures plant reproduction, supports agricultural productivity, and maintains biodiversity (Katumo et al., 2022). Nearly 87,5 % of flowering plants and about 75 % of the most important global food crops depend, at least partially, on animal pollinators, highlighting their indispensable role in ecosystems and in securing global food supply (Ollerton et al., 2011; Klein et al., 2009). Pollinators include a wide variety of animals such as insects (bees, butterflies, beetles, flies), birds, and even some small mammals (Katumo et al., 2022; Ollerton, 2017). Among these diverse pollinators, insects, particularly bees, are especially valuable for agriculture due to their efficiency in pollinating crops and their significant contribution to agricultural economies (Leonhardt et al., 2013; Klein et al., 2006; * Corresponding author. CIHEAM-IAMM - Mediterranean Agronomic Institute of Montpellier, Montpellier, 34090, France. E-mail address: [email protected] (G. Kleftodimos). Contents lists available at ScienceDirect Environmental and Sustainability Indicators journal homepage: www.sciencedirect.com/journal/environmental-and-sustainability-indicators https://doi.org/10.1016/j.indic.2025.100944 Received 2 September 2025; Received in revised form 22 September 2025; Accepted 25 September 2025 Environmental and Sustainability Indicators 28 (2025) 100944 Available online 29 September 2025 2665-9727/© 2025 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ). Senapathi et al., 2021; Ollerton, 2017). In fact, pollination directly enhances the quality and nutritional value of many vital food sources, notably fruits, vegetables, and oilseeds (IPBES, 2016). These nutrient-rich foods are fundamental components of balanced human diets, significantly contributing to nutrition and food security worldwide (IPBES, 2016). In other words, pollination is recognized as a valuable ecosystem service that contributes broadly to human well-being, providing benefits such as medicinal plants, ornamental aesthetics, genetic diversity, and enhanced ecosystem resilience (Millennium Ecosystem Assessment, 2005). The global economic value of animal pollination services is considerable, estimated at between 127 and 152 billion USD annually (Bauer and Wing, 2016; Gallai et al., 2009). Remarkably, despite their relatively modest share of agricultural land use, fruits and vegetables alone constitute over 30 % of this economic value, highlighting their dependency on pollinators (Gallai et al., 2009). However, despite their critical ecological and economic importance, pollinator populations around the world have been alarmingly declining. Numerous studies have identified multiple interconnected factors responsible for these declines, including habitat destruction, intensive farming practices, widespread pesticide usage, diseases caused by introduced pathogens, invasive species competition, and climate change effects (Potts et al., 2010; Cameron et al., 2011; IPBES, 2016; Katumo et al., 2022). Agricultural intensification, driven by the increasing global demand for food, exacerbates these negative trends. Intensive farming often reduces habitat diversity, encouraging monoculture systems heavily reliant on pollinator-dependent crops, thereby heightening vulnerability to pollinator population declines. The decline in pollinator populations, particularly observed in Europe and North America, poses severe risks to both food security and economic development, especially in regions highly reliant on agriculture (Steffan-Dewenter et al., 2002; Potts et al., 2010). Several studies report the decline in pollinator populations, particularly in Europe and North America, where the most consistent data have been gathered. In Europe, for example, approximately 25 % of wild bee species have been lost since the 1980s, while in parts of North America, honeybee colony losses frequently exceed 30 % annually (Potts et al., 2010). Such reductions in pollinator abundance have critical implications for agricultural productivity because many fruit and vegetable producing crops depend on animal-mediated pollination services (Klein et al., 2009; Gallai et al., 2009). Modeling exercises indicate that, once wild pollinator densities fall beneath certain thresholds, crop yields do not decrease linearly but instead exhibit rapid collapse (Gallai et al., 2009). Gallai et al. (2009) estimated that a 50 % loss of pollinator species, without compensatory measures, could result in a 5 %–9 % reduction in the total global value of crop production. This nonlinear response arises because crops often require multiple visits by different pollinator taxa to achieve complete fertilization. In regions of southern Europe, where small-scale farmers rely heavily on fruits and vegetables, yield losses of up to 50 % have been projected under severe pollinator decline scenarios, threatening both local food security and rural livelihoods (Potts et al., 2010). The economic consequences of reduced pollination services extend beyond yield loss. Even when managed pollinators (e.g., commercial honeybees or bumblebee colonies) are deployed to partially substitute for wild insects, Europe could suffer from a multibillion-dollar economic loss, particularly in fruit-dominated systems (Bauer and Wing, 2016). To mitigate these risks, integrated landscape-level and farm-level interventions are required. Agri-environmental schemes, such as establishing flower-rich field margins, reducing pesticide usage, and restoring semi-natural habitats, have been shown to increase wild pollinator abundance and diversity. Simultaneously, the protection and expansion of natural areas provide critical nesting and foraging resources that support pollinator resilience amid intensifying agricultural land use (Potts et al., 2010). In addition, the introduction of alternative managed pollinator species (e.g., Osmia bicornis) can supplement honeybee services; however, such strategies require careful management to avoid disease transmission and adverse effects on native pollinator communities (Cameron et al., 2011). Failure to implement these measures risks a future in which fruit and vegetable production declines sharply, commodity prices escalate, and rural communities suffer decreased food security and economic stability (IPBES, 2016). Therefore, investments in pollinator-friendly agricultural practices, habitat conservation, and diversification of pollination management are essential to maintain crop productivity and ecosystem health under ongoing environmental change. Addressing pollinator decline requires coordinated international actions, combining existing national and local monitoring efforts into a comprehensive global initiative. Given the multifaceted and interacting threats pollinators face, continuous improvement in our understanding of pollinator health and dynamics at local, national, and global scales remains indispensable. Extensive global and national assessments of pollination’s economic value have been conducted (e.g.(Carreck and Williams, 1998; A. Morse and W. Calderone, 2000),), smaller-scale analyses at regional (NUTS 2) and departmental (NUTS 3) levels are relatively uncommon (Borges et al., 2020). These localized assessments are particularly important due to the limited foraging distances of many wild pollinator species, such as solitary bees (Gathmann and Tscharntke, 2002). Precise, smaller-scale evaluations are thus more accurate and relevant for conservation efforts and policy planning. Consequently, the objective of this study is to perform an economic valuation of pollination services at the departmental level (NUTS 3) in France in order to better assess the contribution of pollinators to local and national economies as well as to better assess the venerability of these regions in an even of a “pollination services crisis”. The choice of France as a case study stems from its remarkable agricultural heterogeneity and the availability of detailed cropand region-specific data. France encompasses a wide range of production systems, ranging from extensive cereal belts in the north to intensive fruit and vegetable zones in the south. This diversity allows for the simultaneous examination of both pollinator-dependent (e.g., fruits, vegetables, nuts) and lessdependent (e.g., cereals) crop categories within the same national framework. Moreover, France maintains comprehensive statistical records at the departmental level through sources such as the Agreste database (Minist` ere de l’Agriculture), which facilitate the disaggregation of crop-specific values and surface areas. Finally, ongoing national initiatives, such as the “Plan national Pollinisateurs 2021–2026” launched by the French Ministry of Agriculture, underscore the policy relevance of quantifying pollination services in a country where agricultural lobby groups and environmental agencies actively seek to balance productivity with biodiversity conservation. In order to do so, we employ the Dependence Ratio method introduced by Gallai et al. (2009), which assesses the economic contribution of pollinators to agriculture based on crop-specific pollination dependency levels. France offers a suitable case study due to its diverse agricultural practices and a variety of cultivated crops, including cereals, fruits, vegetables, tubers, and vineyards. This research seeks to accomplish four primary objectives. We first derive, for each department, the total economic value of crop production (EVCP). We then calculate the share of this value that can be directly attributed to insect pollination by aggregating crop-level dependency estimates across the chosen cultivated species. Next, we identify those departments whose agricultural output is most reliant on pollination services, thus revealing spatial hotspots of vulnerability. Finally, we explore the underlying drivers of these spatial patterns by correlating departmental pollination values with factors such as crop types, and the proportion of agricultural land. To achieve these objectives, we construct a detailed set of economic indicators and examine their relationships through correlation analysis. Furthermore, we apply generalized additive models (GAM) to investigate non-linear relationships between crop compositions and the economic importance of pollination. By leveraging the results of our study, it becomes possible to guide more effectively the scientific research and financial investment toward French departments where urgent measures are needed to protect pollinators. This approach can help minimize the risks linked to the Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 2 loss of pollination services (lower agricultural productivity, food insecurity, economic instability in rural areas, etc.). 2. Material and methods 2.1. Study area France was selected as the location of interest for two reasons. First and foremost, detailed data concerning agricultural production at the departmental level, with indicators like total quantity, yield, and surface cultivated, is available and easily accessible. Secondly, and due to its geography, France is rich in terms of biodiversity. It is bordered by the Mediterranean Sea to the south, the Atlantic Ocean to the west, and the English Channel to the north. Its diverse topography includes mountains, forests, rivers, lakes, and plains. Thus, its agriculture sector benefits immensely from its biodiversity, especially from the wide range of pollinators it provides. For that reason, France is a suitable candidate for this research. According to data.gouv.fr, France is divided into 13 regions and 96 departments (excluding overseas territories). In the results part, calculated values will be grouped into departments for comparison and modelling purposes. 2.2. The dependence ratio method The dependence ratio (DR) method is widely used to estimate the economic benefits of pollination services, as it adjusts crop values by their biological reliance on insect pollinators. Earlier studies often equated the full market value of pollinated crops with pollination benefits, leading to inflated estimates. The DR method corrects this by applying crop-specific dependence ratios, which represent the percentage reduction in yield that would occur in the absence of animal pollination (IPBES, 2016; Breeze et al., 2016). For each crop i, the dependence ratio D ᵢ was obtained from published meta-analyses (notably (Klein et al., 2009; Layek et al., 2023)). These ratios are fixed coefficients derived from experimental or expert-based assessments, and they reflect potential yield losses without pollination, regardless of production system or variety. Mathematically, the contribution of pollinators to crop i in department x is: EVIP = (Pi×Qix ×Di) where: •P i =producer price of crop i ( € /ton), •Q ix =quantity of crop i produced in department x (tons), •D i =dependence ratio of crop i. This approach is scalable to small geographical units, such as the 96 French departments, but it does not account for interactions with other agronomic or ecological factors, which may still bias estimates upward. 2.2.1. Economic value of crop production The first indicator is the Economic Value of Crop Production (EVCP), which measures the gross market value of crop outputs in each department. It is calculated as: EVCP =∑ I i=1 (Pi×Qix) where: •P i =producer price of crop i ( € /ton), •Q ix =quantity of crop i produced in department x (tons), •I =total number of crops considered. Here, crop production quantities (Q ix ) were obtained from official statistics for the year 2022. They are reported in physical units (tons), which already integrate yields per hectare and the cultivated area of each crop. Thus, no assumption per acre or hectare was made, values are directly based on production volumes at the departmental level. 2.2.2. Economic value of insect pollination The Economic Value of Insect Pollination (EVIP) represents the fraction of crop value attributable to pollinators. Following Layek et al. (2023) and Gallai et al. (2009): EVIP =∑ I i=1 (Pi×Qix ×Di) This equation parallels EVCP but multiplies by the dependence ratio D i . EVIP thus measures the monetary value that would be lost if pollinators were absent. 2.2.3. Vulnerability ratio After calculating the EVCP and the EVIP for each department, we move to understand the degree of dependence of the department on pollinators and pollination services. Following Gallai et al. (2009), the vulnerability ratio (VR) is the ratio of the economic value of insect pollination and the economic value of crop production. A low VR suggests that the agriculture sector is resilient to pollinator’s decline, and a high VR implies the opposite, which means that there is a significant dependence of the agriculture revenue on insect’s pollination. The equation can be found below. VR =EVIP EVCP 2.2.4. Economic value of insect pollination per hectare of land While EVIP provides the absolute monetary contribution of pollinators, it is influenced by the scale of production. To normalize across departments of varying agricultural land area, we calculate EVIP per hectare (EVIP/ha): EVIP /ha =EVIP ∑Agricultural Land This measure allows meaningful comparisons across regions. For example, a small department with limited farmland but high-value crops (e.g., orchards) may show high EVIP/ha despite lower absolute EVIP. Thus, EVIP and EVIP/ha were considered separately: one captures total economic contribution, while the other adjusts for land area to highlight intensity of pollination dependence. 2.3. Data collection To analyze crop dependence on pollinators, three main datasets were compiled. The first dataset contains crop production figures by department for the year 2022. These data were collected from the French Ministry of Agriculture’s official database (‘Agreste, La Statistique Agricole’, n.d.). In this source, crops are grouped into five major categories: Fruit, Vegetables, Tubers, Vineyards, and COP (cereals, oilseeds, and proteinaceous). The second dataset includes crop-specific pollination dependence ratios. These values were taken from Appendices 1 and 2 of the work by Klein et al. (2009), which classifies crops based on their level of reliance on animal pollinators. The third dataset concerns crop prices, which required a more nuanced approach. Most price data were retrieved from the (‘FAOSTAT’, n.d.) platform, complemented by information from the (‘European Commission’s Eurostat’, n.d.) database. For several crops, we attempted to obtain specific 2022 price data from (‘IndexBox Platform’, n.d.), however these figures were behind a Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 3 paywall and not publicly accessible. As an alternative, we used the freely available data for production volume and production value from the year 2020 to estimate average unit prices. These 2020 values were then adjusted to 2022 levels using the Index of Agricultural Product Prices at Production (IPPAP) (base 100 in 2020) that we got from the Agreste databases, following this formula: 2022 Price=2020 Price ×IPPAP 2022 100 For others, such as tomatoes and sunflowers, we applied a different method, given the unavailability of data for these crops. We used the producer price index (2014–2016 =100) for 2022 and the producer price in 2015, both available on FAOSTAT. The 2022 estimate was derived using this formula: 2022 Price=2015 Price ×IPPAP 2022 100 These procedures allowed us to approximate crop prices with a reasonable degree of confidence. To check the robustness of our estimates, we carried out a sensitivity test by adjusting imputed prices by + -10 % and +-20 % (Table A.4 - appendices). These margins reflect typical price fluctuations in agriculture and provide a reasonable range for uncertainty. Finally, each crop was assigned a pollination dependence level (no increase, little, modest, great, or essential) corresponding to numeric values of 0, 0,05, 0,25, 0,65, and 0,95. All datasets were consolidated into an Excel file and then imported into RStudio for processing and analysis. 3. Results 3.1. National level Although we emphasize the significance of small-scale evaluations of pollination services, assessing them at the national level can still provide crucial insights into the overall importance of pollinators to the French agricultural sector. For the studied crops, in 2022, 34 crops were investigated, of which 26 depend on pollinators in varying degrees, 8 have No Increase, 3 have little increase, 7 have a modest increase, 11 have a great increase, and 5 are essential. 11 crops belong to the fruit category, 9 to the COP, 12 are vegetables, 1 is vineyard, and 1 is tubers. The total national EVCP is 34,8 billion € , of which 4,19 billion € (EVIP) is directly attributed to pollinators, making the national vulnerability 12 %, and the EVIP/ha equals 591,4 € per hectare. Below is the table (Table 1) for crops identified, including crop type, pollinator dependence, EVCP, EVIP, VR, and EVIP/ha. 3.2. Departmental level To better understand how pollination services are distributed across French departments, we imported our data into RStudio. We calculated the indicators for each department (EVIP, VR, and EVIP per hectare). We then created maps using Rstudio to visualize the spatial distribution of these indicators and highlight regional patterns. 3.2.1. Economic value of insect pollination This first map offers a visualization of the Economic Value of Insect Pollination (EVIP) across French departments, expressed in absolute monetary terms. It reveals insights into south/north patterns of agricultural dependency on pollinators, the structure of crop production, Table 1 Crops produced in France, their dependence on pollinators, and pollination service value. Crop Crop type DR Dependance EVCP EVIP VR EVIP/HA Apricot fruit 0,65 Great 215911117,83 140342226,59 0,65 12355,16 Eggplant vegetable 0,25 Modest 52180207,89 13045051,97 0,25 11483,32 Oat cop 0,00 No increase 84345663,64 0,00 0,00 0,00 Cherry fruit 0,65 Great 169372311,31 110092002,35 0,65 14593,32 Chestnut fruit 0,25 Modest 46434047,35 11608511,84 0,25 1290,84 Pumpkin vegetable 0,95 Essential 235868073,14 224074669,49 0,95 30065,03 Rapeseed cop 0,25 Modest 3025374540,38 756343635,10 0,25 614,84 Cucumber vegetable 0,65 Great 163675370,94 106388991,11 0,65 101516,21 Zucchini vegetable 0,25 Modest 174974488,85 43743622,21 0,25 10763,69 Strawberry vegetable 0,25 Modest 316490471,41 79122617,85 0,25 20303,47 raspberry fruit 0,65 Great 54714725,15 35564571,35 0,65 55743,84 Green bean vegetable 0,05 Little 283654970,87 14182748,54 0,05 451,69 Kiwi fruit 0,95 Essential 146543511,00 139216335,45 0,95 35433,02 Oilseed cop 0,05 Little 42636567,52 2131828,38 0,05 73,73 Corn cop 0,00 No increase 3366165532,94 0,00 0,00 0,00 Melon vegetable 0,95 Essential 369269128,92 350805672,47 0,95 27992,79 Turnip vegetable 0,65 Great 15757733,22 10242526,59 0,65 4097,01 Hazelnut fruit 0,95 Essential 19566651,78 18588319,19 0,95 2460,40 Nut fruit 0,95 Essential 128452919,25 122030273,29 0,95 4535,94 Barley cop 0,00 No increase 3283259404,97 0,00 0,00 0,00 peach fruit 0,65 Great 348428885,16 226478775,35 0,65 19809,93 Small peas vegetable 0,00 No increase 110203798,82 0,00 0,00 0,00 pear fruit 0,65 Great 137713670,14 89513885,59 0,65 15159,00 Leak vegetable 0,65 Great 133342851,11 86672853,22 0,65 16152,23 pepper vegetable 0,05 Little 40120989,46 2006049,47 0,05 1921,50 Apple fruit 0,65 Great 950398616,60 617759100,79 0,65 15661,28 Potato tubercule 0,00 No increase 2964227949,53 0,00 0,00 0,00 plum fruit 0,65 Great 324088637,64 210657614,47 0,65 14037,29 Grape vineyard 0,00 No increase 15353138199,59 0,00 0,00 0,00 Rye cop 0,00 No increase 33494414,92 0,00 0,00 0,00 Soy cop 0,25 Modest 232947013,45 58236753,36 0,25 316,67 Sorghum cop 0,00 No increase 67150953,05 0,00 0,00 0,00 Tomato vegetable 0,65 Great 590379776,10 383746854,47 0,65 76079,87 Sunflower cop 0,25 Modest 1362521668,40 340630417,10 0,25 391,28 Total – – – 34842804862,34 4193225907,59 0,12 591,42 Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 4 and potential areas for policy intervention. Departments such as Bouches-du-Rhˆ one (13), Lot-et-Garonne (47), Tarn-et-Garonne (82), and Gard (30) show the highest EVIP values, exceeding 150 million euros, with Bouches-du-Rhˆ one reaching 301 million euros (Map 1). These areas benefit from favorable Mediterranean and Atlantic climates, which promote the cultivation of pollination-dependent crops. Longer growing seasons and higher productivity intensify their reliance on insect pollination. In contrast, departments in northern and central France, characterized by cooler, wetter conditions and a dominance of cereals and livestock, display lower EVIP values. This spatial distribution reveals that pollination is economically critical in southern and western France, making these regions priority zones for pollinator conservation policies. Maintaining pollination services here is not only an ecological concern but also a strategic economic necessity. While the absolute EVIP map effectively identifies where the economic stakes are highest, it is highly dependent on land area, which can bias the analysis, so it is essential to complement this perspective with the EVIP per hectare (EVIP/ha) indicator. 3.2.2. Economic value of insect pollination per hectare To enhance the interpretation of EVIP per hectare (EVIP/ha) across French departments, a quantile-based classification was applied. Given the limited dispersion of EVIP/ha values, using tertiles improved the visualization of spatial contrasts by categorizing departments into high, medium, and low pollination values per hectare. Unlike the absolute EVIP map, which reflects total economic contributions, the EVIP/ha map (Map 2) emphasizes pollination efficiency relative to cultivated land. This reveals new patterns: western coastal regions, notably Bretagne and Pays de la Loire (e.g., Loire-Atlantiques and Finist` ere). In these regions, horticulture, floriculture, and market gardening are widespread, often in small plots that require intensive pollination, leading to high economic returns per unit of land. Similarly, Bouches-du-Rhˆ one in the Mediterranean zone exhibits the highest EVIP/ ha values as it benefits from favorable climatic conditions and diversified cropping systems, heavily reliant on pollination services. Conversely, departments within the ˆ Ile-de-France region (e.g., SeineSaint-Denis, Hauts-de-Seine, Essonne) display low EVIP/ha values, which illustrate the dilution effect of land pressure and urban expansion. Here, the agricultural footprint is minimal and often fragmented. Similarly, departments in central and eastern France, dominated by cereal and livestock farming, show generally moderate to low values. Notably, some departments with high absolute EVIP, such as Lot-etGaronne (47) or Gard (30), do not necessarily appear in the top tier for EVIP/ha. This discrepancy reveals that their high value stems more from land area than pollination efficiency, emphasizing the need for both indicators in complementary use. Ultimately, the quartile-based EVIP/ha map illustrates that high pollination value per hectare is not evenly spread across France, but rather clustered in regions where climate, land use, and crop systems create favorable conditions for pollinator-dependent production. It shifts the discussion away from "where is there the most agriculture" to "where does agriculture rely most efficiently on pollinators." The EVIP/ha map offers a refined lens on where pollination services are most productive per hectare, but it still does not reflect the economic risk associated with pollination dependence. For that, we must turn to the vulnerability rate (VR), which quantifies the proportion of total agricultural value at risk from pollinators decline. 3.2.3. Vulnerability ratio The third map (Map 3) representing the absolute vulnerability ratio provides a continuous view of the proportion of agricultural value Map 1. Mapping the Economic Value of Insect Pollination in French departments. Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 5 dependent on insect pollination within each French department. Unlike EVIP or EVIP/ha, the VR reflects the structural exposure of agricultural systems to potential pollinator decline, independent of the total or perhectare value. Departments such as Alpes-de-Haute-Provence (04), Hautes-Alpes (05), Corr` eze (19), and Tarn-et-Garonne (82) exhibit the highest vulnerability rates, exceeding 0,4 and reaching up to 0,58. These regions, often characterized by mountainous or Mediterranean climates, have fragmented agricultural landscapes dominated by highdependence fruit and vegetable crops, such as apricots, apples, or melons. In contrast, departments in northern and central France, where urbanization, cereal production, and livestock farming prevail, show lower VR values. These systems are typically more mechanized and less reliant on ecological services like pollination. Interestingly, while Tarn-et-Garonne (82) appeared among the top departments in both EVIP and VR, others like Corr` eze (19), with modest absolute EVIP, rank high in VR due to their structural crop dependency. These high vulnerability rates are not necessarily correlated with total agricultural output or land area. Many of the most vulnerable departments have limited agricultural surfaces, but are highly specialized in pollination-sensitive production. The VR map thus highlights structural vulnerabilities that could result in significant economic impacts if pollination services decline, particularly in regions with small-scale, specialized agriculture. Moreover, combining VR analysis with climate and land use data reveals that Mediterranean and mountainous areas, already prone to climatic stresses like drought and frost, face compounded risks, reinforcing their critical dependence on maintaining pollinator populations. 3.2.4. Implications and key insights The combined analysis of EVIP, EVIP per hectare, and vulnerability rate (VR) offers a detailed view of how insect pollination supports agriculture across French departments. It shows that pollination services do not carry the same weight everywhere. In southern and western regions, especially under Mediterranean and oceanic climates, the absolute EVIP is highest, reflecting the large-scale production of fruit and vegetables that heavily depend on pollinators. However, when looking at EVIP per hectare, coastal regions like Bretagne and Pays de la Loire emerge, where smaller but more diverse and intensive cropping systems make pollination services highly valuable per unit of land. The VR indicator brings another dimension: it highlights areas such as Alpes-de-Haute-Provence and Corr` eze, where even modest agricultural sectors are structurally very dependent on pollinators, making them more vulnerable to their decline. Together, these three perspectives show that pollination’s economic role varies by both scale and intensity, shaped by climate, crop diversity, land use, and regional specialization. These findings make clear that protecting pollination services requires targeted, region-specific strategies, balancing both economic importance and ecological risk to support sustainable agriculture. 3.3. Identifying departments where pollination has a significant importance to the agriculture sector 3.3.1. Correlation matrix 3.3.1.1. Correlation matrix of crop types and pollination indicators. The correlation matrix analyzes the relationships between three major crop categories, FRUIT, VEGETABLE, and COP (Cereals, Oilseeds, Protein crops) (Vineyard and tuber crops were excluded from the correlation analysis, as their associated EVIP, EVIP per hectare, and vulnerability values were systematically zero across all departments, making it statistically impossible to compute meaningful correlations for these categories) and four key indicators reflecting economic dependency on pollination services: Map 2. Mapping the Economic Value of Insect Pollination per hectare of agricultural land in French departments. Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 6 ● EVCP_tot: total agricultural income, ● EVIP_tot: total economic value of insect pollination, ● EVIP/ha: economic value of pollination per hectare, ● VR_moy: average vulnerability to pollinator decline. The analysis of the correlation matrix (Fig. 1) reveals important statistical patterns across French departments, shedding light on the differentiated role of crop types in shaping the economic significance and ecological vulnerability of pollination services. Starting with vegetable cultivation, we observe a strong and significant positive correlation with EVIP/ha (r =0,84, p =0 <0,001), confirming the critical dependence of vegetables such as melon, cucumber and pumpkin on insect pollination. In departments where vegetable farming is prominent, the economic value per hectare is notably high. Additionally, these regions display a weak but statistically significant positive correlation with total EVIP (r =0,19, p =0,03 < 0,05). These areas combine economic efficiency with a certain degree of ecological fragility, especially in the absence of crop diversification. Fruit crops, although known for their pollination dependency, show a weak but significant correlation with EVIP/ha (r =0,27, p =0,009 < 0,01). Despite high dependency ratios in species like apple, pear, and apricot, their impact remains regionally confined and diluted. In contrast, COP crops display a moderate and significant negative correlation with VR (r = − 0,36, p =0,004 <0,01), confirming their role in providing structural resilience. This inverse relationship is coherent with the biological characteristics of major staples like barley, oats, and sorghum (RD =0), as well as partially dependent crops like sunflower and rapeseed (RD =0,25). Finally, the link between EVIP/ha and vulnerability (VR) is moderate and statistically significant (r =0.38, p =0,006 <0.01). This result points to a clear pattern: departments deriving the highest per-hectare value from pollination services are also among the most ecologically sensitive. This reinforces the need for targeted conservation policies in economically valuable yet ecologically exposed areas. 3.3.1.2. Scatterplot of EVIP/ha vs vulnerability (VR). To better Map 3. Mapping the Pollination vulnerability in French departments. Fig. 1. Correlation Matrix of crop types and pollination indicators. Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 7 understand the link between the economic value of pollination services and the vulnerability of agricultural systems, we constructed a scatterplot crossing EVIP/ha with the vulnerability rate for each department. This approach allows us to visualize how the value of pollination per unit of land is related to the risk of pollinator decline. The scatterplot (Fig. 2) plots French departments based on two variables: EVIP per hectare ( € /ha) on the x-axis and vulnerability to pollination decline (VR) on the y-axis. Each department is represented by a numerical label (e.g., 006 for Alpes-Maritimes). Overall, we can see from Fig. 2 that the form of the scatterplot is an elliptical cloud with a slight upward trend, indicating a general but non-linear association between EVIP/ha and vulnerability. A dense cluster is visible between EVIP/ha values of 10000–15000 euros and VR levels between 0,3 and 0,4. At the upper end of the spectrum, departments such as LoireAtlantiques (044) and Pyr´ en´ ees-Orientales (066) report both high EVIP/ha values (19303 € and 16879 € , respectively) and high vulnerability rates (VR =0,41 and 0,44). These results reflect their specialization in high-value, pollination-dependent crops, particularly vegetables (e.g., over 43000 € /ha for VEGETABLE production in Loire-Atlantiques). Similarly, Cˆ otes-d’Armor (022) and Finist` ere (029) display EVIP/ha values exceeding 17000 € , consistent with their intensive agricultural systems fostered by oceanic and temperate climates. Same thing for Alpes-Maritimes (006), despite a relatively small agricultural base (EVCP ≈9 million € ), stands out with high vulnerability (VR =0,48) and a high EVIP/ha (15989 € ), reflecting the strong reliance of its Mediterranean horticultural production on pollinators. At the opposite end, highly urbanized departments such as Hauts-deSeine (092) and Seine-Saint-Denis (093) exhibit very low EVIP/ha (0 € and 576 € , respectively) and low vulnerability (VR =0 and 0,10), reflecting the near-absence of productive agricultural land. Territoire de Belfort (090) also reports low EVIP/ha (4618 € ) and vulnerability (VR = 0,20), consistent with its small surface area and industrial-economic orientation. Other departments like Essonne (091) and Seine-Maritime (076) present modest EVIP/ha values (8533 € and 8700 € ) and moderate vulnerability, linked to the dominance of COP crops and relatively less land of fruits and vegetables. Between these two extremes, departments such as Cantal (015) and Haute-Loire (043) show moderate EVIP/ha levels (12508 € and 13584 € ) combined with lower-than-average vulnerability (VR =0,31 and 0,33), characteristic of livestock-oriented agricultural systems in the Massif Central. Southern and western departments, with Mediterranean or oceanic climates, tend to favor intensive vegetable and fruit farming, increasing both EVIP/ha and vulnerability. Northern and eastern departments, where cereals and industrial crops dominate, show a little less reliance on pollination. Mountainous and livestock-oriented areas like Auvergne and the Massif Central lie in a balanced middle zone. However, the scatterplot as a whole reveals a more nuanced reality: most departments cluster within a relatively narrow range of vulnerability and EVIP/ha values. This indicates that, regardless of crop specialization, the decline in pollination services has the potential to affect nearly all regions to varying degrees. The observed patterns suggest that additional factors, beyond agricultural structure alone, must be considered to fully understand the exposure of each region to pollinator decline. 3.3.2. GAM model 3.3.2.1. Observed vs predicted values of the economic value of insect pollination per hectare of land. Fig. 3 illustrates the relationship between the observed and predicted values of EVIP/ha from the GAM model. The points cluster tightly along the reference line, indicating a highly accurate model fit. The minimal dispersion confirms the strong predictive power of the model, consistent with the adjusted R 2 of 0,97 and the 97,6 % deviance explained. This validates the model’s robustness in capturing the underlying structure of the data. 3.3.2.2. Smooth terms: non-linear effects of crop categories. Fig. 4 below displays the estimated smooth terms for the effects of FRUIT, VEGETABLE, and COP crop areas on the log-transformed EVIP/ha. Fig. 2. Scatterplot of EVIP/ha vs Vulnerability (VR). Fig. 3. Observed vs predicted values of the Economic Value of Insect Pollination per hectare of land. Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 8 ● VEGETABLE: The strongest effect is observed for vegetables, with a sharp rise in EVIP/ha up to 20000 ha, before flattening. This supports the finding from the correlation analysis that vegetable area is the primary driver of EVIP/ha, due to the high pollination dependency of many vegetable crops (e.g., melon, pumpkin, tomato). ● FRUIT: The effect is positively non-linear, showing a steep increase up to approximately 10000 ha, followed by a plateau and slight decline beyond 13000 ha. This suggests a diminishing marginal return of pollination services in fruit-dominant departments beyond a certain threshold. ● COP: A negative non-linear effect is observed. EVIP/ha decreases with increasing COP area, then stabilizes. This is consistent with the fact that COP crops (e.g., cereals, rapeseed, oats) have little or no dependence on insect pollination, thus reducing the relative value of pollination services in such areas. 3.3.2.3. Model diagnostics. The figures below (5, 6, 7, and 8) present the standard diagnostic plots used to evaluate the statistical validity of the GAM model: ● QQ plot of deviance residuals (Fig. 5): The residuals align closely with the reference line, suggesting that the normality assumption is satisfied. ● Residuals vs linear predictor (Fig. 6): The residuals are randomly scattered around zero, without any visible pattern, confirming the absence of heteroscedasticity or systematic bias. ● Histogram of residuals (Fig. 7): The distribution appears symmetrical and centered around zero, supporting the normality of errors. Fig. 4. Estimated smooth terms for the effects of FRUIT, VEGETABLE, and COP crop areas on the log-transformed EVIP/ha. Fig. 5. QQ plot of deviance residuals. Fig. 6. Residuals vs linear predictor. Fig. 7. Histogram of residuals. Y. Blili et al. Environmental and Sustainability Indicators 28 (2025) 100944 9 Senapathi, Deepa, Fründ, Jochen, Albrecht, Matthias, et al., 2021. 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