Understanding climate change through plants: a visit to the IU Southeast Herbarium
Nov. 28, 2012
Where most people see a field of flowers, David Winship Taylor sees specimens.
Specifically, the IU Southeast biology professor visualizes the flowers as neatly pressed, dried plant parts referred to as herbarium specimens -- plant samples that can provide crucial information on topics such as climate change patterns and the preservation of threatened species.For the past 20 years, Taylor has curated the IU Southeast Herbarium, a collection of nearly 8,000 plant specimens from a five-county area, and the only active such resource in southern Indiana and Northern Kentucky.
Taylor's personal research focuses on the evolution of flowering plants, analyzing fossilized flowers for clues about their origin, reproductive biology and ecological role. Currently, he is working on an article about the pollen size of the earliest flowering plants during the Cretaceous period, examining pollen size through time in different groups of flowering plants.
His field research varies from the seemingly routine classification of plants found in Indiana and Kentucky counties to exotic discoveries made overseas at archaeological digs in England, China and Jordan.
In 1999, Taylor and co-researchers were conducting a dig in Jordan when they unearthed the oldest flowering plant fossil leaves ever discovered in the Middle East, dating back to the Early Cretaceous Period over 100 million years ago. The researchers also discovered the leaves of an aquatic fern on that trip. But Taylor talks with equal pride about taking IU Southeast undergraduate students to the nearby 2,339-acre Charlestown State Park each summer in search of previously unidentified native and invasive plants.
Located in Southern Indiana, Charlestown State Park was once an ammunition plant owned by the military. The park's limestone glades are so near the surface of the soil that trees don't thrive there, Taylor said. The result is a proliferation of prairie plants that include a rare orchid not often seen in the state, and some instances of the Eastern prickly pear, the single cacti species native to Indiana.
"We are seeing a growing number of southern species crossing the Ohio. These lists play an important role in understanding change, in climate and in native vegetation," he said.
The herbarium serves as an important resource for other organizations, as well.
Recently, Jeffrey D. Carstens of the Iowa-based North Central Regional Plant Introduction Station contacted Taylor for location information on blue ash trees, which are somewhat uncommon in Indiana.
The organization is a collaborator in a nationwide effort to preserve the genetic diversity of the North American ash and was seeking seed samples for preservation.
"In the past, epidemics that led to loss of the American chestnut and elm species resulted in permanent loss of important forest and landscape trees," Carstens said.
Using the resources of the IU Southeast Herbarium, Taylor was able to advise Carstens on specific sites that historically documented the presence of the blue ash. Carstens used the location information to target documented populations of blue ash in order to find sample seeds, which are being deposited into the seed storage facility devoted to preserving the genetic diversity of plants.
The herbarium's online database also offers an easy-to-navigate catalog of species searchable by scientific or collector name, genus, family, county or state. Many of the cataloged plants are found by active volunteers, some of whom have no academic ties to IU Southeast.
One of those volunteers, Bill Thomas, is working on his third publication, in the Proceedings of the Indiana Academy of Science, about plants from the five-county area that have not previously been described in print. He is working in collaboration with Dick Maxwell, the professor emeritus who first established the IU Southeast Herbarium in the 1970s.
Thomas has found and identified an invasive plant that typically grows throughout Asia. "It was the first time it had been reported in the U.S.," Taylor said. "Hopefully it won't survive."