Conference Agenda

Global land use and climate change are major drivers of rapid biodiversity declines and impaired ecosystem services - particularly in Mediterranean areas. Here, olive agroforestry systems can play a crucial role in sustainable land use development, given their economic, cultural, and ecological importance. Depending on their local and landscape management context, they can benefit from pest suppression services provided by key organisms such as birds, bats, and arthropods – and likewise contribute to biodiversity conservation.

The ECO-OLIVES project studied these relationships on 192 olive trees located in 12 olive groves from the Monte Pisano region in Italy. We will present results from the first two years of this project (2022-2023): At the landscape level, higher proportions of surrounding semi-natural habitats significantly promoted species richness and abundance of birds, bats, and arthropods in olive groves. Related to this, experimental exclusions of birds and bats (compared to controls) resulted in lower yields and increased pest infestation rates of olives, while systematic pruning techniques led to opposite effects at the farm level. Integrating insights from socio-ecological studies, we discuss our findings with focus on challenges and opportunities of how transdisciplinary research can contribute to Sustainable Development Goals in biodiversity conservation and land use.

The global challenge of insect pests in agriculture demands sustainable solutions. Recent research underscores bats' pivotal role in integrated pest management, positioning them as vital natural enemies of agricultural pests. Bats exhibit top-down effects on crop pests, providing a valuable pest-consumption ecosystem service. Enhancing habitat heterogeneity and providing additional roosts encourage bat insectivory, but gaps persist in understanding the direct impact. In the Mediterranean, organic farming synergizes with bat activity, emphasizing habitat structure. Bats prefer organic farming, with a scale-independent effect on activity. However, landscape structure management is crucial for increasing bat richness. Even forest bat species may prey on agricultural pests, as observed at the Abruzzo Lazio and Molise National Park (Italy), underscoring the importance of forest patches and treelines within agricultural landscapes. Important research gaps include sublethal bat echolocation effects on tympanate moths, indirect impacts on plant pathogens, and active arthropod pest surveillance. So-called “common species” such as Savi’s and Kuhl’s pipistrelles are key pest suppressors: molecular tools have identified their diverse diets including many pest insects, which highlights the associated ecosystem service. Sustainable management practices should therefore prioritize these bat species, often overlooked in conservation strategies, balancing bat conservation with economic and social sustainability.

Birds and bats frequently co-occur in agroecosystems. However, information about their environmental responses and ability to provide common ecosystem services, like pest control, is still lacking. We analyzed the effect of landscape structure and agricultural management on bird and bat biodiversity, and the role of birds and bats in pest control, in apple orchards of northern Spain. We found differential responses of birds and bats to landscape structure and orchard features. Bird abundance and richness was higher in forested landscapes and in orchards with dense apple tree canopies. Bat activity and richness was higher in more urbanized and heterogeneous landscapes. These different responses suggest large-scale spatial complementarity in the provision of ecosystem services. Bird assemblage composition and functional diversity were resilient to landscape changes but, in the case of bats, were positively affected by forest cover. Birds exerted top-down control on apple pests. Pest control was positively affected by bird abundance, richness and functional diversity, with behavioral and trophic segregation underpinning these positive effects. Bat foraging activity was unresponsive to the abundance of apple Lepidoptera pests. Forest habitat conservation and orchard management may promote complementarity within and between bird and bat assemblages and improve pest control in apple agroecosystem.

Biodiversity-sensitive land management is gaining interest from policy-makers and land managers, following the increasing global decline in biodiversity that is affecting most groups of species, from the less mobile vascular plants, fungi and soil microbial organisms, to mobile arthropods, big mammals and birds. Among all the economic activities responsible, intensive agriculture has played an important role. Through the Common Agricultural Policies and Nature Conservation laws, the EU has tried to halt this loss, but the efforts are not enough. In recent years the scientific community has provided evidence for the fact that biodiversity can be better managed at a landscape scale. In this context, the EU-H2020 project FRAMEwork has developed and tested an approach able to involve local farmers to develop area-wide biodiversity-sensitive land management aimed at limiting pest insects and supporting beneficials.

In this presentation, we will show the case of the Italian olive growers cluster OliValGraziosa. Monitoring of wild bees and butterflies has allowed us to identify patterns and interactions at local and landscape scale that affect the abundances of these two important groups in a biodiverse olive grove agroecosystem. This knowledge can guide the farmers in the cluster in optimising local and landscape scale management practices.

Ants represent a large proportion of the arthropod fauna in many terrestrial ecosystems, where they play a pivotal role in determining the structure and functioning of local communities. Disentangling the details of their ecology may help to understand the dynamics of such communities and to design ecologically sound control techniques.

The role of ant predation in the biocontrol of pest species has been widely acknowledged. Recent advances show that the control of pest populations by ants can also be achieved through non-consumptive, trait-mediated interactions (TMI), which occur when the pest species perceives the predation risk and modifies its behaviour to escape it. However, ants can also limit the populations of other useful predators through intra-guild predation and thus indirectly favour herbivores and plant parasites. Finally, ants actively tend honeydew-producing pests, such as scale insects and aphids, thus hampering the biological control of these pests.

Disentangling this complex network of interactions requires the concurrence of several different approaches, which range from direct observations of ant behaviour, predation experiments, and trophic analysis using, e.g., stable isotopes, to an effort to identify the compounds that may be involved in TMIs.