Zach McCulloch, 22, of Bloomfield walks a slackline between two trees Tuesday afternoon at Hartford’s Elizabeth Park. He said that he was introduced to the sport, which he explained is popular on the west coast and in Brazil, by a friend last summer. “We’re always out here,” he said. The two inch wide line he was walking Tuesday was stretched between two trees for a distance of about 60 feet. Slacklining has been compared to being on a skinny trampoline, with enough slack to bounce and do tricks. McCulloch put a tarp between the line and the tree trunks in order to protect both the bark and the slackline, he said. He got up on the line by sitting on it and bouncing up and down until he had the height and rhythym going to leap into the air and land gently upon the line.