Heavy loppers are a good choice for smaller diameter culms or canes less than an inch to an inch and a half in diameter. For medium-size canes that are two inches or more in diameter a hand saw will be more effective, particularly if you are harvesting the bamboo for decorative use as a saw can give a cleaner cut.
To efficiently cut larger diameter culms that are three inches or more in diameter or when large stands of bamboo need to be cut down, a chainsaw will be your best bet as it can quickly and easily cut through one or more culms at a time.