Memory Lane

There’s a large-scale project under way to turn back the clock in order to better prepare for the future.

In Napa Valley, the non-profit San Francisco Estuary Institute (SFEI) has been working to establish the historical ecology of a region that has seen huge landscape use changes over the past two hundred years. It has gone from being from a massive estuary with varied ecosystems to a heavily populated stretch of land famous around the world for its wines, climate and culture.

It has also become less climate resistant and lost a great deal of biodiversity.

 A map, two aerial photos and a land survey showing different stages of the area around the Napa River and the city of Napa, Calif., in (from left) 1858, 1942, 2009 and 1858.  Composite by Ruth Askevold/San Francisco Estuary Institute; from left to right: National Oceanic and Atmospheric Administration, U.S.D.A., U.S.D.A., Courtesy of The Bancroft Library, University of California, Berkeley  Image/caption: New York Times

A map, two aerial photos and a land survey showing different stages of the area around the Napa River and the city of Napa, Calif., in (from left) 1858, 1942, 2009 and 1858.
Composite by Ruth Askevold/San Francisco Estuary Institute; (L to R) National Oceanic and Atmospheric Administration, U.S.D.A., U.S.D.A., Courtesy of The Bancroft Library, University of California, Berkeley
Image/caption: New York Times

The SFEI embarked on the task of establishing just how this key watershed once worked, in all its complexity.

Researchers dug deep into every kind of archive imaginable. From the SFEI site:

The Native Landscape View of the EcoAtlas is a composite picture based upon hundreds of independent sources of data. These include eighteenth- and nineteenth-century maps, sketches, paintings, photographs, engineering reports, oral histories, explorers’ journals, missionary texts, hunting magazines, interviews with living elders, and other sources.

Guadalcanal Mitigation Site, an area restored to tidal influence in 2001. Photo: Gena Lasko (CDFW)/SFEI

Guadalcanal Mitigation Site, an area restored to tidal influence in 2001.
Photo: Gena Lasko (CDFW)/SFEI

The goal isn’t so much to recreate the Napa Valley of the past as it once looked as it is to re-establish the estuary and ecology as they once functioned. To improve the once-lush delta to the point that it can better absorb both flooding as well as withstand drought.

A side effect is the return of some of the wildlife and plants that once lived where there are now vineyards, roads and suburbs.

It’s not as extreme as the de-extinction projects of long-gone animals like Revive and Restore, but it is an attempt to re-invent a future that looks, at least just a little bit, like what went before and was almost forgotten.

Tidal mud in Guadalcanal Mitigation Site. Photo: Sally Mack

Tidal mud in Guadalcanal Mitigation Site.
Photo: Sally Mack

Watery Treasure

Draining swamps and wetlands has, over the course of human civilization, been seen as a way to grasp land from the greedy waters that cover most of the Earth’s surface.

Add to this that much of the drained, reclaimed land is then conveniently located on prime river or coastal property, and the terrestrial inclination to dry out wetlands makes even more sense. There’s gold in them there swamps.

A MODIS image from NASA's OceanColor Web shows floodwaters and sediment emptying into the Gulf. Source: PennNews/NASA

A MODIS image from NASA’s OceanColor Web shows floodwaters and sediment emptying into the Gulf.
Source: PennNews/NASA

Conservationists usually look at the loss of ecosystems, plant and animal life, habitat degradation and so on. But the real price of the gold rush mentality is slowly revealing itself.

The impact of river levees on flooding has become well known over the past couple of decades. Heavily developed rivers areas around the world experiencing regular and expensive inundations when water flow in flooded rivers is blocked from flowing into tributaries, marshes or swamps.

I found a report from 2005 that shows the impact of land drainage on Florida – not in terms of habitat loss, but in terms of local and regional climate change.

Human influence has transformed southern Florida. The transformation occurred not only on land converted to cropland or cities, but even in protected and undeveloped areas like the Everglades. Changes in water flows transformed deep-water sloughs into drier sawgrass marshes, and mangrove forests have shrunk dramatically. Source: NASA

Human influence has transformed southern Florida. The transformation occurred not only on land converted to cropland or cities, but even in protected and undeveloped areas like the Everglades. Changes in water flows transformed deep-water sloughs into drier sawgrass marshes, and mangrove forests have shrunk dramatically. Source: NASA

A multi-disciplinary team examined historical land cover and climate evidence from pre-development Florida (i.e. 19th-century), and found that in comparison to a drier, drained modern Florida, local climates were cooler and wetter in summer, and warmer in winter. The lack of local water cover changed local climate patterns.

This begins to get at the argument made by Sandra Postel, Director of the Global Water Policy Project, in a recent piece in National Geographic, namely, that wetlands in their watery form are worth more than the land we take from them.

She cites a new study in the journal Global Environmental Change, which shows that “the global area of freshwater wetlands and floodplains shrank by nearly two-thirds between 1997 and 2011, from an estimated 165 million hectares (408 million acres) to 60 million hectares (148 million acres).”

We’ve never been very good at weighing intangibles against objects of  immediate human value, like land. But Postel makes the argument for putting wetland and watershed services in a language we understand: Money.

Landsat images clearly show different types of landcover in southern Florida. Source: NASA/Robert Simmon

Landsat images clearly show different types of landcover in southern Florida.
Source: NASA/Robert Simmon

Citing the role of wetlands, like those that have been drained in Florida, as well as coral reefs, marshes and tropical forests, in mitigating flood and drought, the research team put together a list of water ‘services’ provided. These include recharging groundwater and filtering water in lakes and rivers, maintaining water levels that facilitate shipping, and several other long-term uses.

The total value of global ecosystem services to humans was evaluated at $120 trillion/year (for 2011). This is compared to a global GDP of  $75.2 trillion/year for the same year.

Now, the question is this:

If we look at everything through the lens of cost effectiveness, do we really believe humans can provide all the same services at a better price, even assuming we could develop the technology to do so?

Is a new condo development, mall, golf course or business center really the most cost efficient way to make use of the golden value of the world’s wetlands?

Flyways and Wetland Rotation

Flock of snow geese on unflooded farmland in Skagit ValleyPhoto: Mesa Schumacher

Flock of snow geese on unflooded farmland in Skagit Valley
Photo: Mesa Schumacher

Farmland gain across the world often means habitat loss of wetlands – important habitats for migratory birds. An interesting project proposed adding an old crop to the regular rotation on a number of farms originally won from deltas and estuaries: namely, the crop of water. I picture a watery mosaic in flux, with changing colors of visiting bird flocks instead of green grains. It’s easy to forget that less than a century ago, many of the areas we now associate with large farms were plains and deltas.

For some farms along well-known migratory bird flyways, farmers agree to let their fields flood as part of a yearly crop succession, rather than trying to keep the fields dry and/or irrigated year-round. The migratory birds are provided with link in a geographic chain, allowing them to land and feed. What’s interesting is that the farmers gain, as well. The flooding has led to increased nutrients in the ground, a reduction in weeds, and overall soil improvement.

The Nature Conservancy (TNC), which initiated the plan in cooperation with a consortium of partners, worked together with farmers in the Skagit Valley, Washington. In California’s Central Valley, TNC purchased farmland for the wetland experiment. The plan doesn’t work for all kinds of fields, crops or farmers; for example, it works best in grain fields, but orchards and vineyards that have taken over old flyway areas aren’t suited for annual flooding. Still, many farmers have reported no net loss in having a water crop in their rotation, and overall satisfaction with the routine.

In the Skagit Valley, Washington, over a dozen species of shorebirds have returned to land and feed on migratory routes lost to them during the course of the 20th century. Similar projects are underway elsewhere around the world.

More:

The Nature Conservancy: Farming for Wildlife (Washington State)

National Geographic articles: Field flooding in California here and in Washington State here

World Wetlands Day

Image: Waterist @ deviantart.com

Image: Waterist @ deviantart.com

Bogs, marshes, swamps – wetlands. They soak up excess water in times of flooding, release water in times of drought, are home to a wild array of life, purify groudwater, and make for the settings of some of the very best thrillers.

It’s World Wetlands Day today. WWD marks the date of the signing of the Convention on Wetlands, called Ramsar Convention, on 2 February 1971, in the Iranian city of Ramsar on the shores of the Caspian Sea. Might be a good day to go get your feet wet.

A nice short description of why wetlands are so good and important.