The Heard sanctuary has five habitats including blackland prairie, wetlands, bottomland forest, upland forest and white rock escarpment. Each habitat is unique and offers a variety of plants and animals that live in the specific environments.
A prairie habitat is an ecosystem dominated by grasses, small broad-leaved plants and wildflowers. Prairies are level or hilly grasslands usually characterized by deep, fertile soil with almost no shrubs or trees. Trees may be present, but less than 10% of the area in these broad tracts of land has a tree canopy. Typical grasses of the North Texas native grassland such as here at the Heard Wildlife Sanctuary are big bluestem, little bluestem, switch grass and yellow Indian grass. You may see good examples of these on the Bluestem Trail.
Prairies were maintained naturally for thousands of years in part by grazing animals such as bison and pronghorn, and browsers like deer. Natural prairie fires burned off the dry brown thatch that the grazing animals missed. The fires killed the woody saplings that otherwise would have encroached upon the prairies.
Natural prairie areas with bison and other prairie animals disappeared as human settlers developed and inhabited this community. Bottomland woodland habitats, such as seen on the Hoot Owl Trail, were generally left alone since the infrequent flooding of these areas meant the land was not good for farming. The rolling expanse of open prairie was the most desirable land to farmers and settlers. Prairies were plowed under and changed into farmland and homesteads. Once humans were established, they also disrupted the prairie’s natural cycle of rebirth and succession by aggressively controlling fires whenever possible. Non-native grasses were introduced for grazing of livestock. As suburban development and businesses replaced the farming communities, again the prairie land was the most logical and desirable place for building. Due to human factors, the famous once expansive North Texas native prairie is now the rarest of habitats in the area.