As the leaves fall from trees in five Norwalk parks this autumn, signs are going up to raise public awareness about the diversity and value of the "urban forest."

Dan Landau and Bill Levin, of the Norwalk Tree Alliance, are on the lookout for special types of trees. Landau and Levin then "tag" the trees with signs to alert parkgoers about what they might be missing: more than 30 varieties of trees that are native to southwestern Connecticut.

"I think a lot of people have lost touch with it, especially people who live in cities and downtown areas," says Landau. "There aren't many trees that grow in those areas."

Their little plastic signs, which can be found in areas such as Cranbury Park and a park around Lockwood-Mathews Mansion Museum, give a short description of the tree and a QR code for people who want to find out more with the help of their cellphones.

Connecticut's forested trees are an important resources, but many of those species, such as the Ash Borer, is at risk, according to the Norwalk Tree Alliance. 

"Not only is it going to eliminate that particular species, but various animals and birds depend upon that species, so it could change the whole ecology of the area," says Levin.

The alliance believes the best way to stop that from happening is to build awareness, so volunteers will continue tacking up signs for the next two weeks.

The tree-sign campaign is funded by a federal grant.