Epsilon Archive for Student Projects

Abstract

Pollinators are vital for maintaining ecosystem functioning and supporting human well-being, both through their contributions to agricultural production and their role in cultural practices. Yet, pollinator populations are in global decline, with urbanisation emerging as a major driver. Remote sensing–based habitat models offer promising tools for pollinator conservation, but their application in urban contexts remains limited. To address this gap, we adapted the Zulian et al. (2013) crop pollination model for Berlin, parameterizing it via a novel expert elicitation approach (double dichotomous survey). We mapped relative pollination potential (RPP) across the city and validated predictions using pollination network data from urban grasslands. Spatial patterns in RPP reflected the distribution of nesting and floral resources, with urban green spaces showing the highest suitability. RPP was positively correlated with network connectance, a proxy for pollination redundancy and resilience. For less mobile pollinators (small and medium body sizes), this relationship was linear, whereas for highly mobile pollinators it plateaued beyond an estimated habitat suitability threshold of ~10%. This suggests diminishing gains in connectance, and thus in pollination resilience, at high habitat quality levels. Identifying such thresholds could potentially inform urban conservation planning by establishing minimum habitat quality targets to sustain resilient pollination services.