Integrating local and ecological knowledge to assess the benefits of trees for ecosystem services: A holistic process-based methodology

Management decisions in agriculture regarding landscape structure, biodiversity conservation, food production, climate adaptation and other planetary issues need to be supported by sound data and innovative solutions. The food system can and must become a part of the solution, particularly if it integrates nature-based solutions promoting biodiversity as services, such as pest control provided by local birds. Birds have been shown to contribute to invertebrates' predation and pest control, among many ecosystem services, in agricultural landscapes, especially where trees are present. Trees are also services providers and can contribute to ecosystem regulation, shelter and foraging of species, among other important contributions. In this study, we developed a methodology that integrates species, trait, and crop data; pest predation indicators and local farmers' expertise, to determine the consumption of pests by birds, in intensive farming systems of Central Portugal. Our aim was to investigate the relationship between birds and service provision over a tree gradient, at the landscape level. For that, we used point count data to estimate the daily consumption of invertebrates by birds, based on energy requirements and life cycle characteristics of each species. Using species guilds, we related habitat requirements to pest control services, which showed higher predation in annual crops close to trees or woody vegetation compared to the ones with just crops. Further, we analysed the methodology's main challenges and strengths. Lastly, we concluded that the holistic characteristic of the developed process would guide stakeholders and policy' elaboration more effectively, as we have learnt that farmers' participation enabled more accurate analysis and results and could bring them closer to the research process.