Besides the heat sinks of rock,  concrete,  bricks and asphalt,  wouldn't it follow that buildings give off heat in direct proportion to their mass,  dimensions,  and air conditioning levels?  Air conditioning is basically a way to put hot air outside and replacing it with cooler air,  all inside an insulated box.  So you would expect at 100 degrees outside,  and 75 inside,  that 25 degrees of heat exiled to the out of doors makes some contribution to the ambient air temps,  trees or not.