<p>Alley cropping agroforestry, which integrates trees with crops, offers a sustainable approach to agriculture by enhancing biodiversity and ecosystem resilience. However, the effects of agroforestry on the seasonal and spatial distribution of arthropods providing regulative ecosystem services remain understudied. Carabid beetles, key weed and pest regulators, occur across a wide spectrum of habitats and environmental conditions, and their sensitivity to habitat changes makes them ideal indicators of the effects of agroforestry. We sampled five paired temperate alley cropping and open cropland systems in Northern Germany from February to July, using pitfall and emergence traps to assess the abundance, diversity, and functional roles of active and overwintering carabids at varying distances from tree rows and in adjacent open croplands. Our study revealed that agroforestry increased taxonomic as well as functional diversity of carabids, promoting forest-associated, granivorous, and small- to medium-sized beetles. In contrast, open croplands were dominated by a few large and omnivorous open-habitat species. Although more individuals overwintered in open croplands, trait diversity was higher within agroforestry systems – especially close to the tree rows, which supported diverse communities crucial for natural weed and pest control. Tree rows facilitated early-season recolonization by providing overwintering habitats for diverse spring breeder communities and the late season emergence of diverse autumn breeder communities, whereas open croplands were characterized by the emergence of few highly abundant autumn breeder species later in the season. Overall, agroforestry fosters early emergence of functionally diverse carabid communities, likely enhancing natural weed and pest control and supporting biodiversity conservation.</p>