Rain gutter bookshelves. Or use just one along the bottom under the white board. Display the science and social studies books to tie together a unit and intergrate literacy Toys Rooms, Rain Gutter, Books Display, Gutter Bookshelves, Kids Books, Plays Rooms, Books Shelves, Gutter Bookshelf, Kids Rooms
tree inspired shelving from collegelifediy.com. There's a whole cool article with different trees.