In one-year experiment, we assessed decomposition rate of three lichen genera viz. Usnea Dill. ex Adans, Everniastrum Hale ex Sipman and Parmotrema Mass. in 15 sample buckets at botanical garden of S.S.J. Campus Almora. Fresh samples of theses lichens were removed from Quercus twigs situated in Morunaula temperate forest of Kumaun Himalaya. Agricultural soil samples were also collected for their chemical analysis and lichen decomposition activity. Individuals of selected lichen thalli were mixed separately with this soil. After six months of decomposition, observations were taken. Usnea was found to be the fastest decomposed lichen (about 91%) and increased the value of soil macronutrients- pH, N, P & K. Value of all the macronutrients was found higher in lichen decomposed soil as compared to lichen free soil. Lichen improves soil fertility after their decomposition. Changing weather and climate is a challenge to maintain the fertility of the soil of the area.