This crossection from a little 1 inch trunk diameter five foot high tree grew on bare rock in the sun
 It was 33 years old.  Nearby, also on bare or nearly bare rock werea couple of  fifteen foot tall trees
over 100 years old.  The older trees had the shape of brocolli which is very characteristicof the older junipers.
 They were 7 to 9 inches in diameter.