|If you cannot see this release correctly, please see the
online version here.
|Editors� note: A video, maps, photos and a
briefing paper on carbon-capture farming are available at the USGS
California Water Science Center Web site at http://ca.water.usgs.gov/news/ReleaseJuly23_2008.html.
California and UC Davis begin
large-scale Delta �carbon farm�
Project will study
best ways to capture atmospheric CO2, reverse island subsidence
|Imagine a new kind of farming in
the Sacramento-San Joaquin River Delta � �carbon-capture� farming,
which traps atmospheric carbon dioxide and rebuilds lost soils.
The U.S. Geological Survey (USGS), the California Department of Water
Resources (DWR) and the University of California, Davis plan to make it
DWR has awarded USGS and UC Davis a three-year, $12.3 million research
grant to take the concept of carbon-capture farming to full-scale in a
scientifically and environmentally sound way.
Long-standing farming practices in the Delta expose fragile peat soils
to wind, rain and cultivation, emit carbon dioxide (CO2) and cause land
subsidence. To capture or contain the carbon, farmers would �grow�
wetlands. In doing so, they would begin to rebuild the Delta�s unique
peat soils, take CO2 out of the atmosphere,
ease pressure on the Delta�s aging levees and infuse the region with
new economic potential.
Carbon-capture farming works as CO2 is taken out of the air by plants
such as tules and cattails. As the plants die and decompose, they
create new peat soil, building the land surface over time.
The USGS and DWR have already partnered on a pilot project that shows
the promise of carbon-capture farming. On deeply subsided Twitchell
Island in the western Delta, USGS scientists recorded elevation gains
of more than 10 inches from 1997 to 2005 on two seven-acre test plots
as cattails, tules and other plants grew, died and decomposed. The
process leaves behind roots and plant remnants that compact into a
material similar to what formed the peat soils initially.
Construction on the new wetlands, covering up to 400 acres on Twitchell
Island, is scheduled to start in the spring of 2009.
�This project is an investment in California�s future that could reap
multiple benefits over several decades � for California, the nation and
the world,� said Dr. Roger Fujii, the project director and Bay-Delta
program chief for the USGS California Water Science Center. �It will
build on the results of the ongoing Twitchell Island Pilot Project and
assess on a large scale the ability of re-established wetlands on Delta
peat islands to sequester carbon, reverse subsidence and provide an
economically sustainable land-use practice.�
�UC Davis scientists will play a major role in this project. We�ll be
providing the scientific expertise necessary to gain a better
understanding of the factors controlling carbon capture in these
re-established wetlands,� said Dr. William Horwath, a professor in the
UC Davis Department of Land, Air and Water Resources and the James G.
Boswell Endowed Chair in Soil Sciences.
Added David Mraz, chief of DWR�s Delta-Suisun Marsh Office, �The
developing carbon market holds great promise for regaining land
elevation in the Delta. It could provide sustainable farming
opportunities for Delta farmers and an economic incentive to sustain
the existing Delta levee system.�
Throughout the Delta, oxidation of the soils from farming practices has
resulted in land-surface subsidence � a steady loss of elevation. As a
result, most of the farmed Delta islands are more than 20 feet below
the surrounding waterways and are permanently protected by levees.
The falling land surface threatens the stability of the region�s
levees, which in turn protect the Delta�s rich agricultural lands and
the conveyance of much of California�s water supplies. Water flowing
through the Delta�s levee-protected farmland provides fresh water to
more than 25 million Californians and millions of acres of farmland in
the Central Valley.
The research will develop wetland management approaches that maximize
carbon sequestration and subsidence reversal. It will also evaluate and
seek to minimize other potential environmental consequences, such as
how to effectively manage any changes in mosquito populations.