Eric, depending on the local conditions Cyp colonies can very likely last hundreds of years, particularly if there are factors that keep ecological variables fairly constant (for example fire). From what I've seen (very limited) many Cyps like to colonize disturbed sites such as mines and road cuts which are in a state of rapid change. Such stands are likely to expand quickly and then have a serious population crash a few decades later unless some factor maintains the situation. Most often light is the limiting factor.
There is a fair amount of research showing that fire and herbivory play important roles in many cases, and the removal of ground level vegetation (including new tree saplings) can extend the life of a particular orchid colony, or revive ones in decline. While individual plants can be set back or even killed by such disturbance, more often these are a benefit. I would love to know how many C. tibeticum are eaten each year by yaks for instance! Many terrestrial orchids can in fact go dormant for years on end (Isotria and Triphora are especially good examples). The theory is they are "waiting" for better conditions to grow, flower, and hopefully reproduce. This ability alone potentially extends the age of colony.
You also have to imagine that in most cases Cyps take a long time to mature, especially in nature - I'd guess no less than 6-8 years for really good conditions and perhaps decades in the worst. One way you can estimate age is by looking at the rhizome - if it is long with lots of internodes you know the plant is old - possibly decades old. That BTW is a good indication if your plant is wild collected or not since most Cyps haven't been in propagated long enough artificially to create really long rhizomes - not yet at any rate.
