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Abstract Trees in residential environments are affected by a unique combination of environmental and anthropogenic factors, including occasional insect outbreaks that are increasing in frequency and severity due to climate change. We studied loblolly pine trees infested by bark beetles in a residential backyard in a southeastern US city. We investigated the responses of tree and stand‐level transpiration to environmental factors (solar radiation, atmospheric vapor pressure deficit, and soil moisture), severe weather events (strong winds and heavy storms), bark beetle infestation, and human actions (insecticide treatments and tree removals). We used constant heat dissipation probes to make continuous sap flux measurements (J₀) in tree boles. Over 22 months of the study,J₀of trees with confirmed infestation decreased from ~90 to ~60 g cm⁻² day⁻¹andJ₀of the rest of the trees increased from ~60 to ~80 g cm⁻² day⁻¹. One infested tree died, as itsJ₀steadily declined from 110 g cm⁻² day⁻¹to zero over the course of 2 months, followed by a loss of foliage and visible signs of severe infestation 6 months later.J₀was sensitive to variations in incoming solar radiation and atmospheric vapor pressure deficit. In most trees,J₀linearly responded to soil water content during drought periods. Yet despite complex dynamics ofJ₀variations, plot‐level transpiration at the end of the study was the same as at the beginning due to compensatory increases in tree transpiration rates. This study highlights the intrinsic interplay of environmental, biotic, and anthropogenic factors in residential environments where human actions may directly mediate ecosystem responses to climate. 

Abstract Water smart cities are increasing their use of irrigation and misting to cope with extreme heat and drought. This is being enabled by widespread use of rainwater tanks, stormwater capture and storage systems, and recycled sewage wastewater to irrigate street trees as well as private and public green spaces. These alternative water resources provide new options for cities to better withstand and function under extreme summer heatwave conditions with little or no impact on drinking water supplies. Small‐scale approaches to evaporatively cool urban animals, vegetation habitat, and people are showing initial success. However, ongoing testing and modeling are needed to understand the impacts of scaling up these interventions and to evaluate their cost‐effectiveness. We describe current innovations in irrigation of Australian cities to help policy development in other countries and cities experiencing similar climates with episodic summer heatwaves.