Rare PA Plant a Litmus Test for Climate Change

  • Dr. Mary Ann Furedi, Western Pennsylvania Conservancy, counts Northestern bulrush in Tioga State Forest. Photo: Kara Holsopple

  • Northestern bulrush thrives in vernal pools. It's rated highly vulnerable on an index scientists are using to measure impacts of climate change on wildlife. Photo: Kara Holsopple

March 16, 2013

Subtle shifts in temperature may be impacting flora and fauna close to home.  Scientists are using a new tool to measure the impact of climate change on wildlife in Pennsylvania. 

Dr. Mary Ann Furedi of the Western Pennsylvania Conservancy is monitoring a species of bulrush in Tioga State Forest in Northcentral Pennsylvania. Furedi counts flowering heads of Scirpus ancistrochaetus, the scientific name for the Northeastern bulrush in a small area.  Then, using a simple formula, she can estimate the total population in this particular half acre clearing in the forest. It’s one of 15 bulrush sites Furedi will monitor this year. 

The waist high plants have turned brown and brittle at the end of their growing season.  The thin sedge has drooping flower heads which look like exploded fireworks.    They’re rare--federally protected-- but more plentiful in Pennsylvania’s vernal pools--temporary wetlands, rich with wildlife.

“This population that we looked at today actually looks like its in really good shape in terms of outside threats,” Furedi says. 

She says that’s due to it’s open tree canopy, which lets in lots of light.  The site also has good hydrology, or the amount of water available throughout its growing season.  And there’s no threat of deforestation on this state land.  But another risk may be at play.

“We were interested in climate change and how climate change impacts different species.  From our standpoint we are looking at it more from what species are vulnerable to climate change,” Furedi explains.

To determine this, Furedi uses the Climate Change Vulnerability Index or CCVI. It’s a software tool that allows scientists to enter data about wildlife species and weather pattern predictions to come up with a picture of how the species will be impacted by climate change.

Mammals, birds, amphibians and plants can all have their numbers crunched through the software. It scores how exposed the species is to climate change, and how sensitive.

Furedi says more wet winters and hot dry summers may spell trouble for the Eastern bulrush.

“Given the life history and the temperature and moisture changes that possibly occur in Pennsylvania, that we’ll have either a shrinking of the species within its range in Pennsylvania, or there may be a shift northward,” she adds.

The score for Northestern bulrush is “highly vulnerable." But knowing the score could help win the game in the long run.

“You can really look at those factors, that make it vulnerable, are there ways to really work that into management efforts, whether it be protection of certain pools that are higher in the range of Pennsylvania, or whether to do monitor pools,” according to Furedi.

She says the bulrush is also litmus test for what’s happening in vernal pools and the surrounding landscape.  Getting accurate counts and monitoring the bulrush over the next five years could also help determine how other species in vernal pools, like salamanders, will fare in a changing climate.