The tree-huggers are out — with their axes. An environmental preservation event being held today in 30 nature areas across the state focuses on cutting down trees. It’s an effort to reclaim native prairie lands as invading shrubs and trees crowd out prairie grasses and flowers. Mark Edwards of the Iowa D-N-R is director of the AmeriCorps program and is helping organize today’s “Cut a Tree for Earth Day” event.He says about three-quarters of Iowa used to be prairieland, or between 25 and 30-million acres. Today, there are about 30-thousand acres of prairie left in Iowa.Information on specific locations can be found at: “www.state.ia.us/dnr/volunteer/prairie.html” or by calling (515) 281-8959. With the loss of the prairie, Edwards says Iowa is the most biologically altered state in North America.