Herbicides may not be sole cause of declining plant diversity

Feb 04, 2014

The increasing use of chemical herbicides is often blamed for the declining plant biodiversity in farms. However, other factors beyond herbicide exposure may be more important to species diversity, according to Penn State researchers.

If herbicides are a key factor in the declining diversity, then thriving species would be more tolerant to widely used herbicides than rare or declining species, according to J. Franklin Egan, research ecologist, USDA-Agricultural Research Service.

"Many ecotoxicology studies have tested the response of various wild to low dose herbicide exposures, but it is difficult to put these findings in context," said Egan. "Our approach was to compare the herbicide tolerances of plant species that are common and plant species that are rare in an intensively farmed region. We found that rare and common plant species had roughly similar tolerances to three commonly used herbicides."

This could mean that herbicides may not have a persistent effect in shaping plant communities.

The researchers, who report their findings in the online version of the journal Environmental Toxicology and Chemistry, said that over the past several decades, in the same time that the use of herbicides was on the rise, other factors such as the simplification of crop rotations, segregation of crop and livestock and increasing mechanization have also been rapidly evolving. In addition, the clearing of woodlots, hedgerows, pastures and wetlands to make way for bigger fields has continued apace and resulted in habitat loss.

While the findings are preliminary, the approach could be effective in clarifying the implications of herbicide pollution for plant conservation, Egan said.

"These findings are not an invitation to use recklessly," he said. "There are many good reasons to reduce agriculture's reliance on chemical weed control. But, for the objective of plant species conservation, other strategies like preserving farmland habitats including woodlots, pastures and riparian buffers may be more effective than trying to reduce herbicide use."

Explore further: EU, others: Catch plans for Bluefin tuna threaten recovery

add to favorites email to friend print save as pdf

Related Stories

Which direction are herbicides heading?

Oct 11, 2011

2,4-D is coming back. What many might consider a "dinosaur" may be the best solution for growers fighting weed resistance today, said Dean Riechers, University of Illinois associate professor of weed physiology.

Recommended for you

EU, others: Catch plans for Bluefin tuna threaten recovery

13 hours ago

(AP)—The European Union, Japan and other nations hunting for the eastern Atlantic Bluefin tuna are fearful that Turkey's unilateral decision to exceed catch limits agreed last year is threatening the stock ...

Salish Sea seagull populations halved since 1980s

14 hours ago

The number of seagulls in the Strait of Georgia is down by 50 per cent from the 1980s and University of British Columbia researchers say the decline reflects changes in the availability of food.

Banksias differ on resilience to climate change

16 hours ago

Research into the germination requirements of four Banksia species (Proteaceae) endemic to the South West Australian Floristic Region (SWAFR) has found certain species may be more vulnerable to climate change ...

China bans ivory carving imports for one year

22 hours ago

Beijing has imposed a one-year ban on the import of ivory carvings, amid international criticism that rapidly-growing Chinese demand could push wild African elephants to extinction within a generation.

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.