Historical ecologists map a changing landscape.

This is a really interesting article to read about California. How California changed over time and new generations don't have a clue what was there before. This change is not just in California its all over the world.

This article was written on Friday, March 27, 2009 by Eric Simons.
In this article Robin Grossinger, a scientist at the San Francisco Estuary Institute did field work. He found old pictures about 150 years old pictures from local history books, looking for any landmark-a creek, a 200 years old oak tree. When he found one he took pictures to document the evidence. Grossinger is a historical ecologist, merging history and ecology to figure out the environment of our great, and great, great, great grandparents. When he compared those landscapes with the present, he was surprised to see how everything was changed. Streams that weren't streams, wetlands where there used to be beaches, thick groves of tree where there used to be plains and plains where there used to be thick groves of trees.

Grossinger's colleague Alisson Whipple, an environment analyst, studied the valley oaks area. Roughly the area along Highway 101 from Morgan Hill to Gilroy - using a 1939 aerial photo and a 2005 aerial photo. She found a decline from 1,976 trees in 1939 to about 1,000 trees in 2005. Grossinger and Whipple found a few
photographs from the late 1800s with dense oak forests and some explorers' accounts that mentioned thick, shady woodland. They decided to do more detective work. This led, late last winter, to one of Grossinger's field trips to find and photograph remnant oak trees. They'd both started to suspect that they were going to find evidence of higher tree density in the past, but Grossinger hadn't heard an actual number. Whipple, who was finishing the report, told Grossinger that she had an estimate: Something like 50,000 trees. Grossinger's eyes widened. "Fifty thousand," he said. "Wow." In fact, in the finished report, the number went to 60,000.

The central bay shoreline of a few hundred years ago was made up of lagoons and long, curling white-sand beaches, where native Californians picked strawberries out of sand dunes. The creeks that flow through the South Bay were mostly engineered by people in the last 100 years, and historically fanned out underground to create swampy wetlands. Less than 200 years ago, there were so many octopuses overflowing the bay's tide pools that settlers would walk around grabbing them for dinner.
"Knowing where wetlands are could be useful," Grossinger said. "You could bring back red-legged frog or tiger salamander habitat. That usually means creating artificial ponds, but if you could do that where there used to be a wetland, that's even better."

That's the main point of historical ecology: To give restoration planners a better idea of what they might try to bring back and what might succeed. Like the oak trees: You don't need to return to undeveloped land to bring back oak trees. You just need to plant the right kind of trees in suburban yards and street medians - the kind of thing that cities wouldn't know to do without the historical
context. And then, they suspect, if the oak trees make a comeback, so would a lot of the native species that once benefited from them - meaning that in this case, it wouldn't be just the past, but the future, that would be full of surprises.

http://www.sfei.org/inthenews/SFGate32709-HEmapchanginglandscape.pdf