Evaluating the health of treescapes in polluted urban environments

城市树木提供了众多的生态系统服务和支持生物多样性，但受到人为压力的明显组合。污染、干旱和高温胁迫都是更严重的问题，单独或联合起来都会限制树木的生长和健康。然而，这些影响在景观尺度上知之甚少，部分原因是诸如污染物沉积等压力的影响在长寿物种或相关空间尺度上不容易量化。这种知识差距削弱了我们评估对依赖城市树木的物种（包括各种昆虫群落）的中长期影响的能力。

Urban trees provide numerous ecosystem services and support biodiversity, but are subject to apotent combination of anthropogenic stressors. Pollution, drought and heat stress are all greater incities, and can limit tree growth and health, alone and in combination. However, these effects arepoorly understood at landscape scales, in part because the effects of stresses such as pollutantdeposition are not easily quantified in long-lived species, or at relevant spatial scales. This knowledgegap has undermined our ability to assess medium- and long-term impacts on the species which relyon urban trees, including diverse insect communities.