This document discusses using trees and municipal waste products like wastewater sludge and wood ash to rehabilitate degraded lands and forest stands in Latvia. Experiments show that applying mixtures of wastewater sludge and wood ash to trees leads to increased growth compared to untreated controls. The sludge and ash provide beneficial nutrients like nitrogen, phosphorus, and potassium. The document also explores using these waste products as fertilizers in plantations and for growing biomass crops between rows of trees in agroforestry systems.