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ENVIRONMENTAL PROFILE | CHAPTER 3 HISTORICAL BASELINE CONDITIONS


Located geologically on the Iowan Surface, the Cedar Falls region was last directly glaciated several hundred thousand years ago (Prior 1991). However, in an intense cold period during the Wisconsinan glacial period, 16,000-21,000 years ago, a deep layer of wind-blown dust from the glacial front—called loess—was deposited over the region (Prior 1991). While this created ideal soils for agriculture, loess-derived soils erode very easily when vegetation is removed. Most of the undeveloped up- land soil in the region is prime agricultural land due to the combined effect of loess and centuries of prairie vegetation and plant root turnover.


Prior to the arrival of European settlers in the mid-1800s, Cedar Falls was largely blanketed by a complex mosaic of upland prairie and grassy wetlands on gently sloping land. The abundant wetlands and deep, well-drained upland soils held back much of the precipitation falling on the landscape. In the spring and after signifi- cant rains, water flowed across the land in broad drainageways, only flowing in a distinct channel as the water approached the Cedar River. Groundwater was high in the soil profile, maintaining stable water levels in wetlands and the few distinct streams. The lush, year-round prairie vegetation and abundant surface water sup- plies sustained large populations of game and other wildlife, such as bison, elk, prai- rie chicken, upland plover, meadowlark, and badger. Prairie voles, ground-squirrels and other rodents, as well as a thousand species of insects, formed the base of the food chain. Several hundred species of animals and plants were living in each square mile of ground.


Forests and marshes occupied the Cedar River bottomlands and its large tributaries. Two dozen species of turtles, frogs and other herptiles, as well as several dozen spe- cies of fish and freshwater mussels, lived in the floodplain forests, marshes, oxbows, and Cedar River itself.


Between the prairie and floodplain were oak savannas—scattered and clustered trees with a grassy, flower-rich groundcover. Oak savanna was created by and per- sisted due to wildfires that occurred frequently. The oak savanna grew on the slopes and margins of river valleys, where prairie fires were less intense and flooding did not occur.


In the 1600s, the Cedar Falls region was occupied by people of the Iowa and Dakota tribes, and in the 1800s by the Sac and Fox who arrived from Wisconsin. These tribes regularly used fire to manage their environment, improve hunting, and provide se- curity and ease of travel. This practice helped create the landscape, including the oak savanna that greeted European settlers. The influence of the tribes on the vege- tation of the region was eliminated around 1850 following their departure from the state. The region’s deep, black prairie soil, nearby timber and ready supply of water were an attractive location for Europeans to settle and farm.


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