REIT revenue outside of rent

[Lem Diaz]

I'm finally getting around to learning about REITs.  I've come to learn that the primary (only?) revenue stream for REITs is generated by rents paid out to their tenants.  

What about the other half of the equation, the property's equity value?  Assuming a property increases in value how does the equity get folded into the revenue which then would be paid out to the shareholders in the form of dividends?  Are there other ways REITs produce value that gets translated to dividends?

I can imagine a scenario where a REIT investment manager buys up some property...say a mall...and the value of that land and structure increases over time. Since the REIT is required to pay out 90% of the taxable income as dividends...are they not required to share the equity value to shareholders. Does this only trigger when they sell?
 

Am I even thinking about this in the right way?

Thank you

Lem