Insect pollinators along gradients in differently structured landscapes: importance of the edge effect and small- vs. large-scale agriculture

Informations projet

Happybee

N° de convention de subvention: 101027920

DOI

10.3030/101027920

Projet clôturé

Date de signature de la CE 19 Mars 2021

Date de début 1 Janvier 2022

Date de fin 31 Decembre 2023

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 139 850,88

Contribution de l’UE

€ 139 850,88

Coordonné par

HUN-REN OKOLOGIAI KUTATOKOZPONT
Hungary

Periodic Reporting for period 1 - Happybee (Insect pollinators along gradients in differently structured landscapes: importance of the edge effect and small- vs. large-scale agriculture)

Période du rapport: 2022-01-01 au 2023-12-31

Résumé du contexte et des objectifs généraux du projet

Global biodiversity is in crisis because it has declined massively worldwide over the last seven decades. Some of the main drivers of this decline are agricultural land-use changes, including the loss of natural and semi-natural habitats, a cumulative increase in chemical inputs (pesticides and fertilizers), higher mechanization rates, and the loss of smallholder farm systems in agricultural landscapes. These changes have occurred due to human population growth and increased food production demand. However, biodiversity loss can seriously reduce ecosystem services, including agricultural production itself, e.g. as a consequence of the lack of adequate pollination services.

Based on a recent IUCN report, 46% of bumblebee species are showing a declining population trend in Europe. Bumblebee populations – among other pollinator insects – are very important for food production and also for natural plant biodiversity. For instance, wild bee communities contribute, on average, over 3,000 US dollars per hectare to the production of insect-pollinated crops worldwide. The global annual economic value of insect pollination was estimated to be 153 billion dollars, and 35% of the global production of crops depends to some degree on pollinators. This is why the protection of wild pollinators is one of the key challenges for maintaining world crop production and safeguarding food availability.


Pollinator movements in agricultural landscapes has so far gained limited attention. However, this topic is one of the key aspects related to species dispersal and reproduction, as well as providing a better understanding of ecosystem services. Combining the marking of bumblebees with RFID tags with a homing experiment is a promising novel method, which I used in my study to increase understanding of pollinator movements and their influence on crop yield.

Another of my study objectives was to investigate population changes in insect pollinator species and community changes on a gradient from the crop field edge towards the field interior. I wanted to know which species or taxonomic groups are more common inside crop fields than at the field borders. It is important to understand the distance decay effect of pollinators since they provide an ecosystem service by increasing crop yield.

Additionally, my project objectives involved describing the mechanisms behind bumblebee colony fitness and navigation capacities in the agricultural landscape, while at the same time taking account of the effects of crop type, proximity to semi-natural habitats, and field size. I use commercial buff-tailed bumblebee colonies to simulate real-world processes.

The last objective was to communicate the project results during and at the end of the project. I have already disseminated my project results to farmers and scientists, as well as policymakers, stakeholders, and the general public, via leaflets, different presentations, articles, blog posts, and YouTube videos.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

I carried out a global meta-analysis (a study that takes into account the results of earlier scientific studies) to investigate which species or taxonomic groups are more abundant inside crop fields than at the field edges; the latter is, in general, the more preferred habitat for pollinating insects. I found that both pollinator species richness and abundance were significantly higher at field edges compared to the field centre. However, the edge effect was stronger for pollinator species richness than for abundance.

Based on one European study, common red-tailed bumblebee was one species who abundance was more higher inside the fields (at 50 m from the field edge). One American study showed that several bee species, for instance, bicolored striped sweat bee and Hitchens's sweat bee higher abundances at 100 m from the field edge towards to the field centre. Thus, we have only very limited evidence, which insect pollinator species can be more common inside the fields, than in field edges. Majority of evidence still show that species are more common at the field edges than towards to field centre.


I also carried out very large-scale fieldwork in Austria and Hungary to investigate bumblebee colony fitness parameters and bumblebee navigation capacity in the agricultural landscape. I found that for bumblebee traffic rate (workers flying in and out of the colony), the most important factor was the crop type (winter oilseed rape or winter cereal) and, secondly, the proximity to semi-natural habitats. The field-size effect played a lesser role between the two countries. Traffic rate significantly increased bumblebee colony growth and this, in turn, increased queen brood cell numbers. I also took pollen samples from bumblebees. This helped us to identify exactly what plants (natural plants or winter oilseed rape) bumblebees consumed. Additionally, I conducted a botanical survey assessing which natural plants were available during the time of the study. Results of the analysis showed that bumblebees preferred to forage on the most common natural plants and on winter oilseed rape (i.e. exactly on those resources that were widely available during the experimental period). In the bumblebee homing experiment, I found important interactions between wild plant species richness and proximity of semi-natural habitats, as well as field size. These interactions can be explained through two alternative mechanisms: firstly, in relation to food richness and availability in the agricultural landscape, and secondly, in connection with landscape structure, which may enhance the navigation capabilities of bumblebees.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

My project outcomes are directly science-, food-production- and policy-orientated (including EU agricultural policy and the new EU Green Deal). The project results show how to improve agri-environment schemes effectiveness and under what conditions food can be produced in a more environmentally friendly way, considering both wild plant and pollinator ecology in the agricultural landscape. The results of my research will improve knowledge transfer between the disciplines of ecology, biological conservation, food production, and policy making. Finally, my analyses of agri-environment schemes and conservation are informative for the upcoming reports of various international conservation bodies, including the IUCN, EU Environmental Agency, and IPBES.


In the nearest future, we need to change our ecological–economic trade-off thinking. We need to use more novel techniques in agriculture (for instance, innovative plant protection from herbivores, gene technology, and remote sensing application). Additionally, scientists should be collaborating more with farmers and policymakers. We cannot continue with current agricultural practices because they are no longer sustainable from an ecological perspective. However, new approaches and techniques have to be accepted by farmers, but also the policymakers who set new regulations and strategies at the EU level. We need to develop and improve agri-environment schemes, which are currently the main agroecological and political tool at the EU level. Only in this way can we achieve the goals of the EU Green Deal.

I have already communicated my project results at different scientific events, introduced my project results to farmers, policymakers, as well as to a wider audience.

Teamwork

Fieeldwork with my fiance

Sorting fieldwork material

Tagging a bumblebee for homing experiment