Evaluating the health of treescapes in polluted urban environments

Urban trees provide numerous ecosystem services and support biodiversity, but are subject to a potent combination of anthropogenic stressors. Pollution, drought and heat stress are all greater in cities, and can limit tree growth and health, alone and in combination. However, these effects are poorly understood at landscape scales, in part because the effects of stresses such as pollutant

deposition are not easily quantified in long-lived species, or at relevant spatial scales. This knowledge gap has undermined our ability to assess medium- and long-term impacts on the species which rely on urban trees, including diverse insect communities.