The "Common Garden study" is a scientific
method to determine genetic diversity.
Conducted by planting
different populations of the same species in the same environmental conditions.
If the populations are genetically uniform, the plants will grow out in
a uniform manner, with the same height, flowering dates, leaf widths, and
plants looking identical. Variations between populations are called "ecotypes"
and are created by the plant's interactions with its environment, and those
differences can be seen below for one California native species, Bromus
carinatus from the San Francisco Bay area:
(Left) La Honda woods.. (Center) Marin county chert..
(Right) Marin serpentine soil.
(Left)Pescadero coastal dwarf, (Center)San Francisco sand
dunes, (Right) Skyline mountains.
WHAT DO THE DIFFERENCES IN THESE POPULATIONS TELL US?
Photos Copyright © 1997 and text Copyright ©
2000 by Craig C. Dremann, The Reveg Edge, Box 609, Redwood City, CA.