WWU biologist warns of the loss of plant diversity

  • Sun May 6th, 2012 8:03pm
  • News

The Bellingham Herald

BELLINGHAM — A Western Washington University biologist says global climate change and pollution are not the only major problems threating the environment. The loss of plant diversity may be just as dangerous.

Professor David Hooper shared his perspective at a workshop in California at the National Center for Ecological Analysis and Synthesis, The Bellingham Herald reported Sunday.

Researchers from nine institutions were a little surprised by their findings that were published in the journal Nature this past week. Hooper was the lead author of the paper that shows future species loss could reduce plant production as much as global warming and pollution. Their study is the first comprehensive effort to make such a comparison.

“We were looking for broad patterns across many different studies,” Hooper said.

To arrive at their conclusion, Hooper and the other researchers created a database that drew from 192 experiments in which species richness — the number of plants in a given plot or area — was manipulated and then the impact on ecosystems examined.

They looked at ecosystems on land, as well as in freshwater and marine ecosystems.

They compared how global environmental stressors affected two activities important in all ecosystems: plant growth and the decomposition of dead plants by bacteria and fungi.

The researchers also compared how plant biodiversity loss compared to other global environmental changes, and found the following:

•Where plant species loss this century was 1 to 20 percent, which is considered to be on the lower range of projections, the impacts on plant growth were projected to be negligible. Changes would be ranked low compared to other projected environmental changes.

21 to 40 percent of loss could reduce plant growth by 5 to 10 percent. That effect is comparable to the expected impacts of climate warming and increased ultraviolet radiation due to ozone loss, they said.

At higher levels of extinction, 41 to 60 percent of species, the impacts ranked with major factors of environmental change such as nutrient pollution, acid deposition on forests and ozone pollution.

“Within the range of expected species losses, we saw average declines in plant growth that were as large as changes seen in experiments simulating several other major environmental changes caused by humans,” Hooper said.

What is expected for the next 100 years?

“We don’t know,” Hooper said. “This is a possibility. We’re not saying it is going to happen. The best science we have right now is should this happen, this is some of the effects we’re going to have. Personally, I would rather avoid going there.”

The results highlight the need for stronger local, national and international efforts to protect biodiversity because its loss will have a major impact on the planet, the researchers believe.

Hooper brings that home by talking about the Puget Sound being “one of the most beautiful areas in the world.”

“Even so, in and around the Puget Sound, I think there’s something like at least 25 species that are threatened with extinction. Those range from small wildflowers up to Chinook salmon and orca whales,” Hooper said.