More than 1,000 grade schoolers planted a Hardy Rubber Tree at Potter Park Zoo Friday to celebrate Arbor Day. This year's tree is dedicated to Pete Baker, a board member at the Michigan Arbor Day Alliance Committee who died in a car accident earlier this week. The zoo is holding an Earth Day celebration Sunday. Visitors will be able to watch animals get new toys and get up close with some of them and their handlers at the Party for the Planet. There will also be conservation demonstrations. The party runs from noon to four.