Keep in mind that sometimes "low value" trees are actually "high value" trees. ie: just cuz "it's a mulberry or a boxelder tree" does not always mean it's low value. Every tree serves a purpose -- depends on location, health, susceptability to pests, expected life expentency, etc, etc, etc as to which ones are more "important". I live on 2 acres, and have mostly native trees. Last fall we removed some "competing" trees before they got too big ---- so we had to "pick" which ones to keep. We eliminated some hackberries cuz of the nuisance "lacebugs" prob they have, and we kept black walnut trees next to them. We still have many mulberries, black cherries, "piss" elms, etc too. Lots to consider. I hate to see anybody remove trees in the first place unless it absolutely neccesary. IMO all trees are good.