Featured Research

from universities, journals, and other organizations

Loss of plant diversity threatens Earth's life-support systems, experts say

Date:
March 24, 2011
Source:
Virginia Institute of Marine Science
Summary:
An international team of researchers has published a comprehensive new analysis showing that loss of plant biodiversity disrupts the fundamental services that ecosystems provide to humanity.

Seagrass biodiversity: Because seagrass habitat depends on a few species of plants, lost species are often not replaced, and the effects may ripple up to fishery species.
Credit: Jonathan Lefcheck

An international team of researchers including professor Emmett Duffy of the Virginia Institute of Marine Science has published a comprehensive new analysis showing that loss of plant biodiversity disrupts the fundamental services that ecosystems provide to humanity.

Plant communities -- threatened by development, invasive species, climate change, and other factors -- provide humans with food, help purify water supplies, generate oxygen, and supply raw materials for building, clothing, paper, and other products.

The 9-member research team, led by professor Brad Cardinale of the University of Michigan, analyzed the results of 574 field and laboratory studies -- conducted across 5 continents during the last 2 decades -- that measured the changes in productivity resulting from loss of plants species. This type of "meta-analysis" allows researchers to move beyond their own individual or collaborative studies to get a much more reliable global picture. Their study appears in the March special biodiversity issue of the American Journal of Botany.

"The idea that declining diversity compromises the functioning of ecosystems was controversial for many years," says Duffy, a marine ecologist who has studied the effects of biodiversity loss in seagrass beds. "This paper should be the final nail in the coffin of that controversy. It's the most rigorous and comprehensive analysis yet, and it clearly shows that extinction of plant species compromises the productivity that supports Earth's ecosystems."

The team's analysis shows that plant communities with many different species are nearly 1.5 times more productive than those with only one species (such as a cornfield or carefully tended lawn), and ongoing research finds even stronger benefits of diversity when the various other important natural services of ecosystems are considered. Diverse communities are also more efficient at capturing nutrients, light, and other limiting resources.

The analysis also suggests, based on laboratory studies of algae, that diverse plant communities generate oxygen -- and take-up carbon dioxide -- more than twice as fast as plant monocultures.

The team's findings are consistent for plant communities both on land and in fresh- and saltwater, suggesting that plant biodiversity is of general and fundamental importance to the functioning of Earth's entire biosphere.

Duffy, Loretta and Lewis Glucksman Professor of Marine Science at VIMS, says the team's findings are important locally because estuaries like Chesapeake Bay are naturally low in plant diversity, making them especially vulnerable to ecological surprises resulting from loss of species.

"Salt marshes and seagrass beds depend largely on one or a few species of plants that create the habitat structure," says Duffy. "When such species are lost, low diversity means there is often no one else to take their place and the effects can ripple out through the community of animals, potentially up to fishery species."

In addition to analyzing the general effects of biodiversity loss, the team also sought to determine the specific fraction of plant species needed to maintain the effective functioning of a particular ecosystem -- important information for resource managers with limited human and financial resources to manage forests, marine reserves, and other protected areas on land and sea. The results of this effort were mixed, and the team's ongoing research is tackling this question.

Data from the study did suggest, however, that biodiversity loss may follow a "tipping-point" model wherein some fraction of species can be lost with minimal change to ecological processes, followed by a sharp drop in ecosystem function as species loss continues.

Biodiversity loss in the real world

Recognizing that their findings mostly rest on analysis of short-term experiments (generally a few days, weeks, or months) in relatively small settings, the researchers also attempted to determine how diversity effects "scale-up" to longer time scales, bigger areas, or both. The authors note that these are the real-world scales "at which species extinctions actually matter and at which conservation and management efforts take place."

The team's findings suggest that scale does indeed matter, and that small laboratory and field experiments typically underestimate the effects of biodiversity loss. In the researchers' own words, "Data are generally consistent with the idea that the strength of diversity effects are stronger in experiments that run longer, and in experiments performed at larger spatial scales."

Duffy is now further testing this scaling issue with a 3-year grant from the U.S. National Science Foundation. He is using the grant to establish a global experimental network for studying how nutrient pollution and changes in biodiversity impact seagrass beds.

Study co-author Jarrett Byrnes, of the National Center for Ecological Analyses and Synthesis, says "Species extinction is happening now, and it's happening quickly. And unfortunately, our resources are limited. This means we're going to have to prioritize our conservation efforts, and to do that, scientists have to start providing concrete answers about the numbers and types of species that are needed to sustain human life. If we don't produce these estimates quickly, then we risk crossing a threshold that we can't come back from."


Story Source:

The above story is based on materials provided by Virginia Institute of Marine Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. B. J. Cardinale, K. L. Matulich, D. U. Hooper, J. E. Byrnes, E. Duffy, L. Gamfeldt, P. Balvanera, M. I. O'Connor, A. Gonzalez. The functional role of producer diversity in ecosystems. American Journal of Botany, 2011; DOI: 10.3732/ajb.1000364

Cite This Page:

Virginia Institute of Marine Science. "Loss of plant diversity threatens Earth's life-support systems, experts say." ScienceDaily. ScienceDaily, 24 March 2011. <www.sciencedaily.com/releases/2011/03/110303153116.htm>.
Virginia Institute of Marine Science. (2011, March 24). Loss of plant diversity threatens Earth's life-support systems, experts say. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2011/03/110303153116.htm
Virginia Institute of Marine Science. "Loss of plant diversity threatens Earth's life-support systems, experts say." ScienceDaily. www.sciencedaily.com/releases/2011/03/110303153116.htm (accessed August 1, 2014).

Share This




More Earth & Climate News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Napa Valley Wine Grower Survives Catastrophic California Drought

Napa Valley Wine Grower Survives Catastrophic California Drought

Reuters - US Online Video (July 31, 2014) Despite a severe drought in California, Mumm Napa's winemaker says this season's crop may be better than average thanks to well-timed spring rains. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
New Study Says The Moon Was Deformed Early In Its History

New Study Says The Moon Was Deformed Early In Its History

Newsy (July 31, 2014) Scientists say when the moon was young, it was deformed by the Earth's gravitational pull, which gave it a lemon-like shape. Video provided by Newsy
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