Tree-based land uses enhance the provision of ecosystem services in agricultural landscapes of the Peruvian highlands

Trees can have important impacts on multiple ecosystem services and biodiversity in agricultural landscapes. The influence of trees can extend beyond forested areas and into adjacent land uses, however, this is rarely accounted for in the ecological literature. To better understand the influence of trees in Andean agroecosystems, we examined alternative landscape scenarios in the community of Quilcas (Junin, Peru), where we explored the potential impact of replacing tree-based land uses (with crops and pasture) on landscape carbon (C) storage and soil biodiversity (soil macrofauna and ground vegetation). Additionally, we estimated the influence of tree-based land uses on soil C storage (0-20 cm depth) and macrofauna diversity in adjacent croplands and pastures. Tree -based land uses were dispersed across the landscape and occupied 26 % of the area, including a mix of forest patches, plantations, and hedgerows. Given that above-and belowground C stocks were generally higher in land uses with trees versus those without, the inclusion of trees in this landscape is estimated to increase the total landscape C storage by 153 %. Macrofauna diversity also varied across different land uses, being highest in alder (Alnus acuminata) forests and hedgerows, such that the inclusion of trees enhances overall macrofauna diversity (Shannon Index) by 25 % but appears to have a slightly negative effect (-6 %) on ground vegetation diversity. When accounting for the influence of trees on adjacent land uses, estimates for overall soil C storage at the landscape scale increased by 1.4 %, while macrofauna diversity increased by approximately 5 %. Our findings indicate that the addition of trees can greatly enhance overall C stocks and soil macrofauna diversity in agri-cultural landscapes, and that it is important to consider spatial interactions between land uses to fully quantify and optimize these interactions.