ORC’s Senior Agroforestry Researcher Dr Colin Tosh provides some answers from EURAF 2026.
I went to the 8th European Agroforestry Congress in Neuchâtel, Switzerland ‘Agroforestry at the Heart of Europe’, with a particular mission: to understand as much as I could on what agroforestry actually does for biodiversity. The congress ran from 22–26 June 2026 and included a dedicated session on Biodiversity in Agroforestry, alongside related papers elsewhere in the programme. The conference Book of Abstracts is available here: https://zenodo.org/records/22227050
There was another memorable feature of the meeting: the heat. Neuchâtel was in the middle of a heatwave, with temperatures consistently reaching 35°C and above. I had made matters worse by forgetting to pack shorts. So I spent the week in trousers and a lot of time under trees.
So, what did the biodiversity research actually show? Overall, the picture was encouraging. Across a wide range of organisms, agroforestry tended to increase biodiversity, although there were important exceptions. One of the clearest bird results came from Noëlle Klein of Agroscope and the Swiss Ornithological Institute. In Switzerland, her team compared 17 young silvoarable systems (cropping systems with rows of trees) with 17 nearby controls. Although the systems were only around four years old, 12 of 20 Swiss Agri-Environmental Objective bird species responded positively. Birds associated with structurally varied farmland benefited most, while some species of very open landscapes responded less positively.
A more dramatic example came from Alain Rival of CIRAD, France, working in the Kinabatangan region of Sabah, East Malaysia. More than 60 bird species had been recorded in diversified oil-palm agroforestry plots, compared with the 20–30 species normally found in oil-palm monoculture. However, restored riparian forest (native woodland restored alongside rivers and streams) still supported richer vertebrate communities. Agroforestry can therefore improve farmland biodiversity considerably, but it is not a substitute for conserving natural habitat.
For bats, Jari Vandendriessche of Ghent University presented results from the DigitAF project, comparing 31 agroforestry sites with monoculture controls across Portugal, France, Belgium, the UK and the Czech Republic. Average bat species richness was 4.26 taxa in agroforestry compared with 3.48 in controls. The same study found greater species richness for plants, macro-moths, bees, hoverflies and butterflies. Spiders and carabid beetles, however, gave a more complicated picture. In Vandendriessche’s study, spider and carabid activity-density was lower in agroforestry, and carabid richness was also somewhat lower. By contrast, Lukas Beule of South Westphalia University of Applied Sciences found greater taxonomic and functional diversity of carabids and spiders in German alley-cropping systems, with tree strips providing overwintering habitat and aphid predation greatest near the trees. The contrast shows that effects can depend strongly on system design, management, landscape context and what is measured.
For pollinators, Lærke Bruun of Aarhus University studied four hedgerow–field systems in southern Denmark. Total pollinator abundance was 40–42% higher near hedgerows, and hoverfly diversity was also greater. Interestingly, this did not automatically translate into improved crop pollination, showing that greater biodiversity and greater delivery of a particular ecosystem service are not necessarily the same thing. Luca Cozzolino of CREA in Italy also reported a positive result: a mixed poplar–safflower agroforestry system had the highest arthropod biomass, species richness and evenness among five agricultural systems, as well as better indicators of soil microarthropod quality.
Below ground, the evidence looked particularly strong. Rosy Scholes of the University of Reading studied mature silvoarable systems on five commercial farms in eastern England and found 36% greater earthworm species richness and 45% higher earthworm abundance than in paired arable controls. Vera Marlene Thoss of the Julius Kühn Institute studied six alley-cropping systems across four German federal states and likewise found that earthworms were generally more abundant around tree strips and recovered more quickly beneath trees after spring drought. At a much larger scale, Eva-Maria Minarsch of Justus-Liebig University Giessen presented a global meta-analysis (an analysis combining results from many studies) covering 158 studies and 173 agroforestry systems in 22 countries across six continents. Agroforestry increased microbial population size by about 22%, potential microbial activity by 18% and microbial alpha-diversity by 8% relative to reference land uses (See also: Leaf litter distribution as a key driver of earthworms in a mature temperate agroforestry system).
There were also positive results from vineyards. Célien Durney of Université Bourgogne Europe, Institut Agro Dijon and INRAE studied five adjacent plots in the Cognac region of France and found greater soil microbial activity and microbial community diversity in vitiforestry (integrating trees into vineyards) than in conventional vineyards. Jakob Hörl of the University of Hohenheim, working at Ayl in Rhineland-Palatinate, Germany, also found that tree shade altered the richness and composition of spontaneous vineyard vegetation. Not every result was positive, however. Christa Hirschvogel of ZHAW studied four young agroforestry sites in the Swiss cantons of Zurich, Aargau, Schaffhausen and Lucerne and found no statistically significant effects on soil microarthropods, although there was a slight tendency towards higher biological-quality scores near trees. The systems were only one to six years old, suggesting that some effects may take time to develop.
So, are generalisations beginning to emerge? I think they are. The evidence for birds is broadly positive, although species specialising in open farmland may lose out. Bat richness also appears to increase, though fewer studies were presented. Pollinators, butterflies and moths generally seem to benefit. Responses among spiders and ground beetles are less consistent. The strongest and most consistent evidence may currently be for earthworms and soil microbial communities.
The wider lesson is not simply ‘trees equals more biodiversity.’ Trees create a greater variety of habitats and conditions: permanent strips, leaf litter, shade, cooler and moister microclimates, feeding sites and refuges from cultivation. How much biodiversity benefits therefore depends on tree age, management and the surrounding landscape. Nevertheless, the balance of evidence presented at Neuchâtel was clearly positive. For several groups, the question is increasingly not whether agroforestry can benefit biodiversity, but how large that benefit is, how quickly it develops, and how systems should be designed to maximise it.
Jacquat, R., Roberti, G., & Herzog, F. (2026, July 23). Agroforestry at the heart of Europe – Book of Abstracts of the 2026 Congress in Neuchâtel, Switzerland, June 22-26. https://doi.org/10.5281/zenodo.21359551
Other ORC related contributions to EURAF 2026:
Bauza AMC, Chaudhary VP, Van Colen W, Radzikowski P, Staton T, Scholes RE, Cooper J, Simonson W, Tosh C, Ghaley BB (2026) Economic evaluation of agronomic productivity and ecosystem services in agroforestry systems (p242)
Schmutz U, Venn R (2026) Valuing silvo-arable ecosystem services for agroforestry certification (p200). Paper from Agromix using data from Organic Farm Management Handbook
