Researchers from the Department of forest ecology and the Department of forest conservation and wildlife management at the Faculty of forestry and wood technology, Mendel University (FFWT MENDELU), have investigated the complex interplay between local and landscape factors affecting pesticide distribution in perennial crops such as orchards and vineyards. This research builds upon a previous study focused on the transport and bioaccumulation of pesticides in the agricultural-forest landscape of the Czech Republic, providing new insights into their spread across various ecosystem components.
“We analyzed pesticide residues in soil, plants, rodents, and spiders, enabling us to trace the distribution of these substances from primary producers through herbivores to invertebrate predators. This comprehensive approach offers a holistic view of how pesticides affect different trophic groups and the factors contributing to their accumulation in ecosystems. The findings underscore the importance of environmental and management strategies in biodiversity conservation,” Radek Michalko said, explaining the significance of the study.
The study has revealed the presence of various pesticides, including banned substances, at managed sites, even those under organic farming practices. Highly toxic compounds such as carbofuran, malathion, and methoxychlor—long prohibited for use—were among the detected pesticides:
“The illegal application of these substances cannot be avoided. Their persistence in the environment poses significant risks to biodiversity and ecosystem health. The findings also indicate that organic farming may still be threatened by persistent and illegally used chemicals. The detection of unregistered pesticides like pyraclostrobin highlights severe regulatory shortcomings. These findings stress the urgent need for stricter enforcement and more effective pesticide monitoring to better protect the environment and public health,” emphasized Ondřej Košulič.
The researchers have found that semi-natural habitats, such as meadows and forest biotopes, play a crucial role in reducing pesticide levels in mobile animal species like spiders. These habitats provide refuges with lower pesticide exposure because they are less frequently treated with chemicals compared to intensively managed areas such as fields and orchards. Additionally, the decomposition of organic matter and increased soil biological activity in these habitats can accelerate the degradation of pesticides in the environment. Spiders moving between habitats can often spend most of their time in low-contamination areas, reducing the accumulation of pesticide residues in their bodies. Experts have concluded that maintaining and supporting these habitats in the landscape plays an important role in reducing pesticide exposure.
“The study has also observed an interesting phenomenon: the presence of more web-building spiders correlated with a higher number of detected pesticides. This can be explained by their hunting strategy. Web-building spiders catch flying insects that may come into contact with a broader range of pesticides during their movement through agricultural landscapes. Additionally, spider webs can directly capture pesticides dispersed by wind or during application,” noted Košulič.
The study has also revealed that the distribution of pesticides in the soil is primarily influenced by the type and intensity of land management: “While plants were affected by both local management and the surrounding landscape structure, such as the proportion of forests and shrubs, no significant correlation was found between pesticide levels in rodents and either landscape composition or local management,” noted Michalko.
The research highlights the importance of monitoring diverse ecosystem components to better understand pesticide distribution. It also supports strategies that promote the protection and development of semi-natural habitats in intensively managed landscapes. “Such approaches can mitigate the negative impacts of pesticides on biodiversity and support sustainable agricultural and forestry practices that protect the environment and its biological diversity,” concluded Košulič.
The study was conducted as part of a joint project with the Centre of Ecology, Toxicology and Analytics: “The Impact of Plant Protection Products on Non-Target Animal Species and Regulation of Risky Products in Agriculture”, funded by the Technology Agency of the Czech Republic (BETA2 programme).
The results were published in the prestigious Journal of Applied Ecology, issued by the British Ecological Society, the world’s oldest ecological organization.Contact for further information: Mgr. Radek Michalko, Ph.D., Department of Forest Ecology, FFWT MENDELU, +420 545 134 038, radek.michalko@mendelu.cz; Ing. Ondřej Košulič, Ph.D. Department of Forest Conservation and Wildlife Management, FFWT MENDELU, +420 728 076 516, ondrej.kosulic@mendelu.cz