Are you interested in creating a greener City of Phoenix? In 2010 The City of Phoenix adopted the Tree and Shade Master Plan that laid out the vision of a healthier, more livable and prosperous Phoenix through the investment in the urban forest. Volunteer as a Citizen Forester and become a tree advocate for your community. Citizen Foresters educate the community on the importance of trees while providing assistance for the proper planting and care of the trees throughout the city. Volunteer as a Citizen Forester and Plant a Solution. Available Level One Classes are listed below.