Hello! please would you help me?... can I import a specific kind of tree with specific dimensions like Leaf Area Index, height and / or transpitration? I´d like to simulate the shade that a specific tree gives.

[adolfohermida]

Can I import a specific kind of tree? adding the variables like Leaf Area Index, Height or transpiration

[CherylLau]

You can change the height of imported models or the height of plants in ESRI.lib.  However, setting the leaf area index or transpiration through attributes and having the model change accordingly is probably not possible.  You can see what the tree's shadow would look like in the viewport at a specific time of day by setting the scene light parameters (sun icon in the toolbar), but calculating exactly how much shade it produces is probably not possible.