Due to invasive species, climate change, disease, and logging, U.S. cities are losing a large number of their trees. According to a 2018 study from the US Department of Agriculture’s Forest Service, U.S. metropolitan areas are losing 36 million trees per year. To correct this loss, and utilize another waste product, some U.S. cities are investing in a type of compost that uses both dead trees and human biosolids.
