Nowadays children live in the urban life do really less outdoor activities,which keeps them away from the nature.We can't just ignore the problem that children don't want to go out to observe the nature any more.So we come up with an idea to reconnect them together.Children can make the specimens with the leaves they pick outdoor and then collect them by building "a colorful tree".More specimens,more beautiful and much bigger the "tree" is,which actually motivate them to get closer to the nature.As the children grow older,the "tree" can also be used for decoration and it will bring back their childhood memory too.