Featured Research

from universities, journals, and other organizations

Too Much Of A Good Thing? Excess Nutrients Or Water Limit Biodiversity

Date:
March 27, 2007
Source:
University of Minnesota
Summary:
Too much of a good thing (nutrients or water) actually decreases the diversity of species in an ecosystem while it increases the productivity of a few species, according to a grassland experiment conducted by University of Minnesota researchers.

Too much of a good thing (nutrients or water) actually decreases the diversity of species in an ecosystem while it increases the productivity of a few species, according to a grassland experiment conducted by University of Minnesota researchers.

The reduction in species diversity occurs because increasing the amounts of limiting resources, such as nitrogen and water, makes an ecosystem more homogeneous and consequently reduces the number of opportunities for competing species to coexist. Put another way, it reduces the number of niches, allowing a few species to dominate.

The study, conducted by David Tilman, Regents Professor of Ecology, and Stanley Harpole will be published March 25 in the online version of the journal Nature. Harpole, who is now a postdoctoral associate at the University of California, Irvine, was a graduate student at the University of Minnesota when the research was carried out.

"In essence, the data in the article strongly supports a new explanation for why the world contains so many species," said Tilman. "It shows that plant diversity is directly related to the number of limiting factors (such as soil moisture, nitrogen, phosphorus, potassium and water)."

It also helps explain why grasslands, lakes and rivers that are polluted with nitrogen and phosphorus (usually from agriculture) have fewer species. The reduction of species where the Mississippi River empties into the Gulf of Mexico is one of the best known examples of this phenomenon.

The findings are based on experiments carried out at the University of California's Sedgwick Reserve in the Santa Ynez Valley, where the researchers applied combinations of nutrients and water to plots of grassland. Plots that received all of the resources had the fewest species and highest productivity. They combined this with analysis of the 150 year old Rothamsted Park Grass Experiment. Both supported their hypothesis.

"Our results show that the loss of plant species from a habitat due to nutrient pollution can persist for more than 100 years," Harpole said. "Thus human actions that simplify habitats can lead to long-term loss of biodiversity."


Story Source:

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


Cite This Page:

University of Minnesota. "Too Much Of A Good Thing? Excess Nutrients Or Water Limit Biodiversity." ScienceDaily. ScienceDaily, 27 March 2007. <www.sciencedaily.com/releases/2007/03/070326095643.htm>.
University of Minnesota. (2007, March 27). Too Much Of A Good Thing? Excess Nutrients Or Water Limit Biodiversity. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2007/03/070326095643.htm
University of Minnesota. "Too Much Of A Good Thing? Excess Nutrients Or Water Limit Biodiversity." ScienceDaily. www.sciencedaily.com/releases/2007/03/070326095643.htm (accessed September 17, 2014).

Share This



More Earth & Climate News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. 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