Biology Reference
In-Depth Information
But knowing what is “natural” and deciding what to aim for in the fu-
ture still requires finding out what ecological functions and habitats were
like in the past. This is the specialty of historical ecologist Robin Gross-
inger and colleagues at the San Francisco Estuary Institute. They study
aerial photos, lot surveys, Spanish-era maps, and other archival sources to
reassemble a landscape's historical geography. The aim is not to return
every creek to some former historical state but to bring back what the in-
stitute calls the “broad ecological palette” of original habitats.
This region's commitment to creating a palette of riparian and marsh
habitats, on a scale that dwarfs almost every other watershed project na-
tionwide, promises to revive the health of the bay and its tributaries. What
follows are two chapters on the history and frontiers of restoration. The
first is on the rivers, creeks, and floodplains of the watershed, and the sec-
ond reports on efforts in San Francisco Bay.
“It's time to put the picture back together,” says Josh Collins, a biologist
with the San Francisco Estuary Institute. “The bay is the bottom of local
watersheds, and local watersheds are the top of the bay.”
The earliest documented restoration efforts in the bay's watershed focused
on specific gravel beds, riverbanks, waterfowl habitats, and creeks. These
early efforts occurred on a piecemeal, site-specific basis that was later
dubbed “gardening-style restoration.” Managers paid little attention to the
flow of water from one part of the landscape to another, or to the role of
water in connecting ecosystems.
In the 1970s and 1980s, state water planners found themselves pressed
to protect California's irrigation and drinking water supplies from salt-
water intrusion and environmental challenges. They took a harder look at
the connection between the ocean tides and river flows, and started think-
ing about estuarine processes.
True landscape-level restoration arrived with watershed-wide plan-
ning in the 1990s. Legislation to better manage storm-water runoff
spurred the formation of dozens of planning groups. In these groups, local
landowners, along with representatives from utilities, water districts, and
special interests concerned with specific creeks or rivers, grappled with
common challenges. For the first time, these stakeholders began thinking
about adjacent land uses and environmental quality all along the flow
line—from headwaters to major rivers and the ocean.
But work within single watersheds failed to address larger state water
conflicts. Urban and agricultural water users still refused to relinquish
