Abstract
Well-known Banach space results (e.g., due to J. Koliha and Y. Katznelson/L. Tzafriri), which relate conditions on the spectrum of a
bounded operator T to the operator norm convergence of certain sequences of operators generated by T, are extended to the class
of quojection Fr¿echet spaces.These results are then applied to establish various mean ergodic theorems for continuous operators
acting in such Fr¿echet spaces and which belong to certain operator ideals, for example, compact, weakly compact, and Montel.