If you love trees,
1. don’t slackline on them without putting a towel between the slackline and the trees. I see slacklining done lazily, all the time, in Boulder, Colorado, where I live—and every time I see some young nature-loving adventure types slacklining on ancient, lovely noble old trees, I sadly think “there’s a couple years off that good ol’ tree’s life.”
2. Same goes for bicycle parking.