Land-Mobile Satellite System(LMSS) offer more economical mobile communication services relative to terrestrial radio systems such as cellular and private mobile radio. In realization of mobile satellite communication, the most important problem is occurance of fading depth due to tree shadowing, and multipath propagation effects. As the system is power limited, fading depth is a very critical factor in the link design processes. In this work, a new approach is incroduced to LMSS propagation model in order to determine fading depth. For this purpose, during a period of six months in 1993, L-band propagation measurements were made for 14 different types of trees. The average tree attenuation and tree attenuation coefficient are given in  at L-band. In addition to L-band measurements, in 1996, UHF band propagation measuraments were made for the same trees in Trabzon.