Bernheim Arboretum and Research Forest visiting artist Patrick Dougherty will unveil the large willow sculpture he created on the Bernheim grounds this week.Dougherty has created more than 200 large-scale sculptures all over the world, from a piece for the Brooklyn Botanical Gardens to a Shinto temple in Japan. His raw materials are indigenous tree saplings and branches, like the locally-sourced willow, maple and gum branches that make up this sculpture, but Dougherty just calls them “sticks.”“I like sticks because they’re part of the shadow life of our hunting and gathering past,” Dougherty says. “Kids know everything about sticks. They’re a weapon, a tool, a piece of a wall, a magic wand. For a child sticks are an imaginative object. You imagine what you can do with it and how useful it is.” The North Carolina native has been working with the material since the mid-1980s, when he began exploring the different roles sticks can play that capture people’s imaginations when extended into sculpture.“There are a lot of starting points for them in their own lives, like a bird nest they’ve seen or a lilac bush they’ve played under or a walk they took,” says Dougherty.The Bernheim sculpture is abstract, but the shape suggests two large intertwined snakes. This is no hands-off museum piece. The bodies of the snakes form corridors that dougherty hopes visitors will feel invited to explore.“There’s lots of in and out, there’s lots of corridors, there’s lots of doorways from one part to another. It has a labyrinth feeling,” he says.First, Dougherty creates a stick wall frame from supple green branches, then fills it in with smaller sticks to create lines. The process is deceptively simple. One technique consists of jamming sticks into the gaps in the stick wall to create a layered, tangled texture.“I want these big long lines around the outside of this thing so it looks like it moves, so your eye kind of moves around from one long line to the next, and gives the impression that maybe this little holding area here, this tail of the snake is kind of flying around and spinning,” Dougherty explains.Dougherty’s sculptures are not permanent – the artist says he can get about two good years out of one installation.“You get one great year and one pretty good year. Unfortunately the line between trash and treasure is very thin. And so at a moment you begin losing the illusion that we placed in the piece and it starts to look a little disheveled as it enters its older years,” says Dougherty.Dougherty will speak about his work at 21C Museum tomorrow. His as-yet-untitled stick sculpture will make its debut Thursday at a public event outside of the Bernheim Visitor Center, where it will be on display until 2014.