NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/581251
46 NEBRASKAland • NOVEMBER 2015 E verything around us, that we're driving through right now, would've looked much like the Rocky Mountains," said Cassidy Gerdes, a South Dakota State University (SDSU) graduate student, as we traveled west through northeastern Nebraska. Gerdes was referring to the last Ice Age, when massive sheets of ice came plowing through eastern Nebraska about 12,000 to 14,000 years ago, creating an exceptionally cold climate on the glacier's edge that allowed for coniferous forests to grow. Four thousand years later, the glaciers retreated, and drier conditions gave way to fire, incinerating the vast spruce forests that reached southward as far as Kansas. Rising temperatures transformed the landscape, resulting in the Great Plains. "That's what gave us the landscape that we have today. The trees are gone due to the fire regime, but still, in a few places like along the north facing slopes of the Niobrara River, you find little groups of aspen trees that are glacial relicts," Gerdes said. Ice Age survivors, aspen have been able to persist in cold pockets in Nebraska – micro habitats that have provided conditions needed for this cold-tolerant species to linger. However, Gerdes was not particularly interested in trees as far as her master's project at SDSU was concerned. Instead, the trees were a good story to set the stage for her chasing three special little fish. Special Fish Much like the aspens, species of glacial fish have also been able to endure in cold pockets where local factors allow for cooler, more northern-like conditions to persist. In the Keya Paha Watershed, which begins in Todd County, South Dakota, and extends into Boyd County, Nebraska, Gerdes and a small team of technicians set out to find and study three of those species in the summer of 2013 and 2014. " The Keya Paha Watershed has a unique glacial relict population of stream fish. SDSU researchers sampled three tributary streams in the watershed's instream habitat distribution. CASSIDY GERDES PHOTO BY JENNY NGUYEN PHOTO BY JENNY NGUYEN MAP BY CASSIDY GERDES SOUTH DAKOTA NEBRASKA Keya Paha County Glacial Relicts in the Keya Paha By Jenny Nguyen