Kai McArthur, 11, of Hawaii, joins Gerhard Mannsberger, left, chief of the Austria Forest Service, and Niels-Elers Koch, president of the International Union of Forest Research Organizations (IUFRO), during a tree planting ceremony Sunday at the International Peace Gardens in Salt Lake City. The IUFRO 24th World Congress kicked off Sunday and began with the planting of four trees as a gift to the host city. The group planted a cedar of Lebanon, a pinyon pine, an American chestnut and a European beech at the peace gardens. The IUFRO World Congress, which runs through Saturday, is the largest international gathering of forest researchers and practitioners in the world.