Herbariums Explain The Biodiversity Of The Past, Present, And Future
As climate change and human industry destroy once thriving habitats, scientists are using samples from herbariums to piece together the history of our ecosystem.
Dwayne Estes, executive director of the Southeastern Grasslands Initiative and director of the Austin Peay State University herbarium in Clarksville, Tennessee, described herbariums as plant libraries.
“The herbarium that I curate is about 120,000 specimens. Pretty much every species that occurs naturally, natural or naturalized, in Tennessee or Kentucky we have a specimen of.”
Using the plants in the herbarium, scientists like Estes can learn what type of habitat a plant thrives in or identify a certain plant species. Even new plants can be discovered within the specimens.
Normal's own Vasey Herbarium at Illinois State University opened in 1868 and Estes said that while the older samples collected in the 19th century can be incredibly useful, modern techniques make it easier to pinpoint the location of some species.
"Our collection locality information has gotten more specific, really even since the time I started collecting in the late 1990s,” Estes said. “It was a time ahead of GPS technology being widely available to most members of the public. So, I’d say by the late 2000s most people were collecting GPS-specific data with latitude and longitude.”
He says the lack of location specificity of older specimens (i.e. “collected in Arkansas territory, 1835”) is the biggest drawback of older collections.
Estes also said the techniques for drying and pressing have improved, and the awareness of the dangers of working with chemicals have been a major part in improving rodent and pest treatments.
All these advancements mean healthier research subjects.
“I think our specimens now have a better chance of surviving for hundreds and hundreds of years with little degradation,” Estes said.
But regardless of methods, the information of the past still plays a key role in understanding the history of biodiversity, especially in regards to once thriving species now on the brink of extinction.
“Something that’s happened between the way things were in the 19th century and the 20th century we’ve seen widespread collapse across many groups of plants—and of course we’re hearing those same collapses with wildlife today.”
The loss of huge swathes of habitat is a major reason for the near-extinction or relocation of certain animal species.
Estes said that while forested plant species are still thriving, many non-forest species are dying out as America’s original prairie, savannah, and grassland habitats disappear.
“What old records tell us is these plants used to be very common in the landscape and many of our rarest plants today were tied to these open prairie and savannah habitats in many different states in the east ... many of those plants are vanishing very rapidly and the herbarium specimens testify to that.”
And that fact alone shows how important herbariums are to understanding our ecosystem.
“If we didn’t have the specimens (in the herbarium),” Estes said, “then we would not know that they existed.”
Estes will speak on the process of discovering new species of plants and his work to build the Southeastern Grasslands Initiative at Illinois State University’s Felmley Hall on Oct. 17 at 6 p.m. His presentation is free and open to the public. There will be a reception for Estes at 5 p.m.
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