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.
Canada goose photo by Joan Wozny