Colors of Forest; Colors of California

Some years ago I noticed the San Leandro Square on satellite images of the East Bay watershed area. So I went back there to see what it was. It turned out to be eucalyptus trees, planted in a right-angled shape oriented almost exactly with the cardinal directions. I never did solve the mystery of what it is (it's not obviously a wind break), but the line of eucalpytus does jump out as darker than the surrounding oak forest. So I decided to take the average colors of an Australian forest (all eucalyptus) and compare it against some others. Below are the average colors taken from satellite images of forests around the world, below:


Top left, redwood forest (Prairie Creek Redwoods State Park, California, USA)
Top right, summer temperate deciduous forest (Sproul State Forest, Pennsylvania, USA);
Lower left, eucalyptus (Wollemi National Park, New South Wales, Australia)
Lower right, tropical forest (Parque Nacional El Mirador, Guatemala)


And just for the heck of it, here are the average colors of a few spots in California (not all forested) below:


Top left, the ocean at Pfeiffer Big Sur State Park, California Central Coast
Top right, Prairie Creek Redwoods again, coastal far-northern California
Lower left, Algodones Dunes, Imperial County
Lower right, the concrete and pavement of San Francisco's Sunset District