They are only officially witnessing that you are the person signing the POA document, the they "seal" or rivet the document.  

Month to month tenants accepted rental increase after witnessing owner investment in property (new roof, windows and paint was completed within 20 days of ownership).

@Michael SontheimerI would get the property, and jack the rents up as much as makes sense on the next lease renewal, put them at you would wit the repairs made, if they stay, great, if they leas, great. 

@Byron W. it is affecting everyone.

Earlier this week my mom witnessed the tenant proceeding the further "trim" the tree claiming she is removing dead branches.

Tighten up your analysis and then comeback to the forums with specific questions about what you're having trouble wit.

Even with a written out plan, I have seen, witnessed and experienced failure at it's worst.

If the matter was litigated, you would have a defense to a charge of trespass if you establish from the preponderance of evidence (witnesses, documents, and established facts) that you present in court that the owner intended to abandon or give up all rights to his/her property.   

You might want to have a credible witness such as adjoining neighbor collaborate your account so it doesn't appear that you're covering up a lease violation. 

I mean come on, you are hardly going to be called as the star witness...