You shouldn't have much trouble from leaves, but snow and ice can  
accumulate. I remember when I first joined the list there was a discussion about  snow 
accumulating in a cockpit to the extent that when it started to melt it ran  
into the cabin. This was after many freeze and thaw cycles and the entire  
cockpit became a solid block of ice. There wasn't any damage, just a pain to get  
all the ice out of the cockpit. It took several days using heat lamps to melt  
the ice enough to remove it. You couldn't just go in there with a jack hammer  
and break it up. :)
 
Rummy