Too much water, fertilizer bad for plant diversity

Mar 26, 2007

Too much of multiple good things -- water or nutrients, for example -- may decrease the diversity of plant life in an ecosystem while increasing the productivity of a few species, a UC Irvine scientist has discovered.

This finding provides a new explanation for why grasslands, lakes and rivers polluted with nitrogen and phosphorus, usually from agriculture, contain a limited number of plant species. For example, where the Mississippi River empties into the Gulf of Mexico, the water contains low levels of oxygen and high levels of nitrogen and phosphorus used in fertilizers resulting in reduced plant diversity.

"Our results show nutrient pollution can cause loss of plant species from a habitat that can persist for more than 100 years," said W. Stanley Harpole, postdoctoral researcher in ecology and evolutionary biology at UCI and first author of the study. "This means human actions that simplify habitats can lead to long-term loss of biodiversity."

This study appeared March 25 in the online edition of the journal Nature.

The findings are based on experiments conducted at the University of California's Sedgwick Reserve in the Santa Ynez Valley. Researchers applied combinations of water and nutrients -- including nitrogen, phosphorus and cations -- to plots of grassland and found that areas treated with all of the resources had the fewest number of species but the highest productivity of a select few plant types.

When the many resources that plants compete for become overly abundant, the environment simplifies, and an emphasis is placed on a single environmental factor such as space or sunlight. Only a few species best adapted to the new environmental conditions will thrive, Harpole said.

The experiment, combined with an analysis of a similar 150-year-old study, supports the scientists' theory that plant diversity is directly related to the number of limiting factors such as levels of nitrogen, phosphorus, potassium and water.

Source: University of California - Irvine

Explore further: New conversion process turns biomass 'waste' into lucrative chemical products (w/ Video)

add to favorites email to friend print save as pdf

Related Stories

A renewable bioplastic made from squid proteins

8 hours ago

In the central Northern Pacific is an area that may be the size of Texas called the Great Pacific Garbage Patch. Made up of tons of floating plastic debris, the patch is killing seabirds and poisoning marine ...

The RV Investigator's role in marine science

Dec 12, 2014

We know more about the surface of the moon than we do about our deepest oceans, and only 12% of the ocean floor within Australia's Exclusive Economic Zone has so far been mapped.

Plants with pocket-sized genomes

Dec 12, 2014

Members of Genlisea, a genus of carnivorous plants, possess the smallest genomes known in plants. To elucidate genomic evolution in the group as a whole, researchers have now surveyed a wider range of species, ...

Invasive species can dramatically alter landscapes

Dec 11, 2014

Invasive plant and animal species can cause dramatic and enduring changes to the geography and ecology of landscapes, a study from Purdue University and the University of Kentucky shows.

Recommended for you

'Hairclip' protein mechanism explained

6 hours ago

Research led by the Teichmann group on the Wellcome Genome Campus has identified a fundamental mechanism for controlling protein function. Published in the journal Science, the discovery has wide-ranging implications for bi ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.