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Iowa

Bluebell Hollow Preserve

This preserve is home to the Pleistocene snail and algific talus slopes.


Part of a complex of more than 27 slopes containing perhaps the greatest assemblage of high-ranking rare species and communities in the Midwest.

Location

Clayton County

Size

100 acres

Why the Conservancy Selected This Site

Bluebell Hollow contains several algific talus slopes, a unique natural community that is home to many rare species in the Midwest. Small ice caves, where the core ice is believed to be more than 10,000 years old, are tucked away behind steep slopes of limestone scattered with loose (talus) rock, creating a unique feature called an algific (cold-producing) talus slope. During the spring and summer the air in the ice caves is colder than the outside air. Warm air drawn down into the sinkholes is cooled as it flows over ice, and then escapes through vents in the slopes keeping them at a temperature between 37 and 45 degrees Fahrenheit. In the winter, air in the ice caves is warmer than the outside air, reversing the airflow. As the warm air rises and exits through the sinkholes, the cold air is drawn through vents, freezing the ground water. This makes for a variety of microclimates that support diverse communities and species that were long thought extinct.

What the Conservancy Has Done/Is Doing

This preserve is being managed to protect populations of its many endangered species.

Closed to public

Bluebell Hollow Preserve is not open to the public. Watch website for field trips to this special area.

We’re Accountable

The Nature Conservancy makes careful use of your support.

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