Featured Research

from universities, journals, and other organizations

Restored wetlands rarely equal condition of original wetlands

Date:
January 25, 2012
Source:
University of California - Berkeley
Summary:
Half of all wetlands in the US, Europe and China were destroyed during the 20th century, but a thriving restoration effort aims to recreate marshes and other ecosystems lost. A new study cautions, however, that restored wetlands do not recover to the condition of a natural, undamaged wetland for hundreds of years, if ever. This calls into question mitigation banks that allow developers to destroy one wetland if they create another.

Restored wetlands like this pond converted from agricultural use in Aragon, Spain, may look natural, but a new study shows that it can take hundreds of years for restored wetlands to accumulate the plant assemblages and carbon resources of a natural, undamaged wetland.
Credit: David Moreno-Mateos/UC Berkeley

Wetland restoration is a billion-dollar-a-year industry in the United States that aims to create ecosystems similar to those that disappeared over the past century. But a new analysis of restoration projects shows that restored wetlands seldom reach the quality of a natural wetland.

"Once you degrade a wetland, it doesn't recover its normal assemblage of plants or its rich stores of organic soil carbon, which both affect natural cycles of water and nutrients, for many years," said David Moreno-Mateos, a University of California, Berkeley, postdoctoral fellow. "Even after 100 years, the restored wetland is still different from what was there before, and it may never recover."

Moreno-Mateos's analysis calls into question a common mitigation strategy exploited by land developers: create a new wetland to replace a wetland that will be destroyed and the land put to other uses. At a time of accelerated climate change caused by increased carbon entering the atmosphere, carbon storage in wetlands is increasingly important, he said.

"Wetlands accumulate a lot of carbon, so when you dry up a wetland for agricultural use or to build houses, you are just pouring this carbon into the atmosphere," he said. "If we keep degrading or destroying wetlands, for example through the use of mitigation banks, it is going to take centuries to recover the carbon we are losing."

The study showed that wetlands tend to recover most slowly if they are in cold regions, if they are small -- less than 100 contiguous hectares, or 250 acres, in area -- or if they are disconnected from the ebb and flood of tides or river flows.

"These context dependencies aren't necessarily surprising, but this paper quantifies them in ways that could guide decisions about restoration, or about whether to damage wetlands in the first place," said coauthor Mary Power, UC Berkeley professor of integrative biology.

Moreno-Mateos, Power and their colleagues will publish their analysis in the Jan. 24 issue of PLoS (Public Library of Science) Biology.

Wetlands provide many societal benefits, Moreno-Mateos noted, such as biodiversity conservation, fish production, water purification, erosion control and carbon storage.

He found, however, that restored wetlands contained about 23 percent less carbon than untouched wetlands, while the variety of native plants was 26 percent lower, on average, after 50 to 100 years of restoration. While restored wetlands may look superficially similar -- and the animal and insect populations may be similar, too -- the plants take much longer to return to normal and establish the carbon resources in the soil that make for a healthy ecosystem.

Moreno-Mateos noted that numerous studies have shown that specific wetlands recover slowly, but his meta-analysis "might be a proof that this is happening in most wetlands."

"To prevent this, preserve the wetland, don't degrade the wetland," he said.

Moreno-Mateos, who obtained his Ph.D. while studying wetland restoration in Spain, conducted a meta-analysis of 124 wetland studies monitoring work at 621 wetlands around the world and comparing them with natural wetlands. Nearly 80 percent were in the United States and some were restored more than 100 years ago, reflecting of a long-standing American interest in restoration and a common belief that it's possible to essentially recreate destroyed wetlands. Half of all wetlands in North America, Europe, China and Australia were lost during the 20th century, he said. S

Though Moreno-Mateos found that, on average, restored wetlands are 25 percent less productive than natural wetlands, there was much variation. For example, wetlands in boreal and cold temperate forests tend to recover more slowly than do warm wetlands. One review of wetland restoration projects in New York state, for example, found that "after 55 years, barely 50 percent of the organic matter had accumulated on average in all these wetlands" compared to what was there before, he said.

"Current thinking holds that many ecosystems just reach an alternative state that is different, and you never will recover the original," he said.

In future studies, he will explore whether the slower carbon accumulation is due to a slow recovery of the native plant community or invasion by non-native plants.

Coauthors with Moreno-Mateos and Power are Francisco A. Comin of the Department of Conservation of Biodiversity and Ecosystem Restoration at the Pyrenean Institute of Ecology in Zaragoza, Spain; and Roxana Yockteng of the National Museum of Natural History in Paris, France. Moreno-Mateos recently accepted a position as the restoration fellow at Stanford University's Jasper Ridge Biological Preserve.

The work was supported by the Spanish Ministry for Innovation and Science, the Spanish Foundation for Science and Technology and the National Center for Earth Surface Dynamics of the U.S. National Science Foundation Science and Technology Center.


Story Source:

The above story is based on materials provided by University of California - Berkeley. Note: Materials may be edited for content and length.


Journal Reference:

  1. David Moreno-Mateos, Mary E. Power, Francisco A. Comín, Roxana Yockteng. Structural and Functional Loss in Restored Wetland Ecosystems. PLoS Biology, 2012; 10 (1): e1001247 DOI: 10.1371/journal.pbio.1001247

Cite This Page:

University of California - Berkeley. "Restored wetlands rarely equal condition of original wetlands." ScienceDaily. ScienceDaily, 25 January 2012. <www.sciencedaily.com/releases/2012/01/120124184157.htm>.
University of California - Berkeley. (2012, January 25). Restored wetlands rarely equal condition of original wetlands. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2012/01/120124184157.htm
University of California - Berkeley. "Restored wetlands rarely equal condition of original wetlands." ScienceDaily. www.sciencedaily.com/releases/2012/01/120124184157.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) — Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) — Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) — A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins