Was this a tax lien certificate or a tax deed? There is a big difference and you don't sound like you know which one it is. All states and counties are different, so you need to read through the county documents carefully and consult a local real estate lawyer.
Some counties will only sell the tax debt. If that is the case, you absolutely do not own the property, you can't trespass and you definitely can't cut trees down!
Some county's seize the property and then they actually auction off the property in a tax defaulted auction. Winning bids receive a quitclaim deed and then the bidder has to file the quitclaim deed with the county clerk to get title and officially own the property. Even after you have title, if there is a redemption period in that state, then you want to wait until the redemption period has passed before you make any costly repairs or upgrades. Just winning the bid and paying at the auction isn't the end of it. There are several things to do legally after that.
Every county and state is different as far as what they do with tax defaults, which is why you are getting different answers from different people. You need to go to that county's treasurer and county clerk website (or in person) and carefully read through all the information about how they handle tax defaulted properties.