Scientists unearth ecosystem puzzle piece

07/24/2015

Randall Mitchell in the field

Randall Mitchell, UA professor of biology, at one of the six Cuyahoga Valley National Park sites he and UA integrated biosciences doctoral student Heath Garris examined for a worldwide biodiversity study published in Science. Photo by Sean Kelly


Diverse plant species thrive in areas where plant growth is moderate. This elemental yet worldwide discovery (published July 15, 2015 in Science) has roots in northeast Ohio, thanks to two University of Akron scientists. With the increasingly evident impact of climate change and land use on plant species survival, this new finding could further reveal their sweeping influence on a vulnerable ecosystem.

Heath Garris

For Heath Garris, integrated biosciences doctoral student, work on the study included cutting, gathering and weighing the collected biomass to measure the productivity of the grassland sites.


Randall Mitchell, professor of biology, and Heath Garris, integrated bioscience doctoral student, measured the amount of plant growth and number of species at six grassland sites in the nearby Cuyahoga Valley National Park. They found that the most productive sites, or those with the most plant growth, had many fewer species than the less productive sites they studied.

Mitchell and Garris are among the 62 scientists from 19 countries and six continents who undertook what has been described as a “Herculean” effort to measure biodiversity worldwide. Former UA professor Lauchlan Fraser, a Thompson Rivers University biological sciences professor and Canada research chair in community and ecosystem ecology, led the study.

Global ramifications

Humans depend on high levels of ecosystem biodiversity, but due to climate change and changes in land use, biodiversity loss is greater now than at any time in human history. Consequently, the study findings have global ramifications for biodiversity management and conservation.

“By sampling from all around the world, using the exact same methodology, we were able to make very broad conclusions … important for our understanding of what maintains diversity in natural systems, and how human activities might influence diversity,” Mitchell says.

In Ohio, in particular, the Akron scientists report an abundance of plant growth and a significant effect of productivity on diversity.

“The most productive sites had many fewer species than the less productive sites. Our most productive sites were actually the most productive in the whole worldwide survey,” Mitchell says, pointing to the 7 pounds of plant material per square meter he and Garris collected. “Ohio really can grow plants.”


Media contact: Denise Henry, 330-972-6477 or henryd@uakron.edu.