April 26 marks National Arbor Day, first observed with the planting of more than one million trees in the U.S. state of Nebraska in 1872, and now celebrated all over the world. It aims to raise awareness about the importance of planting trees, as well as the threat certain species and forests are facing in our world today. Our correspondent Ediz Tiyansan visited the Joshua Tree National Park that’s struggling to preserve a rare, iconic species whose numbers are in decline.