Originally Posted by
kirkmc
While that all sounds very nice, it's not true. Nature is brutal and if one species of tree dies out, others will come in and fill the niche. Most likely, the hemlock is, for some reason, more robust than other trees, and has kept them from growing. If they were to disappear, other trees would grow and replace them. I wouldn't worry too much about something like that.
When you walk through a forest, you can see this at work. You can see the taller trees and how the keep the others from getting enough light. You can see saplings trying to survive, that don't make it. If the taller tries die, the saplings will take their place. There are even some trees that give off sap that kills other plants. I'm not sure which one it is, but there's a tree here in the UK where you can see that nothing grows beneath it. (I'm not good with plant names.)
Gassho,
Kirk