Trees dont reduce the temepreture in DF

Dear DF experts
i have a part of city and i modeled it. i set the Layer Boundary as you can see in the figure. when i input the trees as the context or when its disconnected there is no any differences in the results (temperature).
in fact it does not make sense.
have i mistaken in settings?

Perherps you should define the energyplus construction of tree context, then the result may be different.

thank you for the reply @YZZhang
i tried it but the results are not changed.
i almost this component ( DF ContextShade) has a serious bug and it has not any effect on results. even i tried it on the Smaple DF and there was not any changes. maybe @chris can explain about it.