Cost basis

In 2019, I sold a lot in a residential community  that I was holding onto for investment purposes.  I need to know what expenses, besides  title expenses  that I can include in the cost basis. 

Over 6 years I owned this property, which by the way is a vacant lot between two houses,  I paid HOA annual dues, LA county  property taxes, and HOA  mandated maintenance fees to keep vegetation like trees and brush  from becoming a fire hazard. The tree removal had the additional benefit of allowing for a territorial view.  

Can any of these expenses be included in the cost basis?  Can the tree removal be counted as an improvement if not an expense?

Thanks in advance for your responses.