More than 10,000 new trees will be planted across Spokane over the next two years as part of an initiative unveiled Friday by Mayor David Condon to beautify neighborhoods and help soak up troublesome stormwater. “Trees add beauty and character, and play a major role in our plans to be smarter about how we use vegetation to help keep stormwater from entering our river,” Condon said during an Arbor Day celebration that included recognition for those who have long helped promote development of healthy urban forests throughout the city.