>Tips for Success
dnr > wildlife viewing guide > ecology:
The following pages provide brief introductions
to some very important ecological concepts. By reviewing these fun,
interactive pages (and testing your skill and knowledge with a quiz
or two), you can gain a clearer understanding of the natural world and
the wildlife that lives there.
Biodiversity | Succession |
Food Web | Conservation |
Carrying Capacity |
Endangered Species |
The Great Lakes | Wetlands
Succession: Changing Land, Changing Wildlife
To an ecologist, the term succession refers to
the predictable changes that occur in the plants and animals that
live in an area over time. See how these changes affect an abandoned
Michigan farm field. (interactive
|Originally, this farm field was a deep forest filled with towering
beech and maple trees.
||Stage 1. Over time the forest was cleared for
farming, bringing about major changes to the kinds of plants and
wildlife that could live here.
||Stage 2. After several years of farming, this
field was abandoned. For the next few years, annual weeds, grasses,
wildflowers, and other plants invaded the bare soil, creating
habitat for mice, meadowlarks, and other open- field wildlife.
|Stage 3. Eventually, shrubs and small trees
seeded into the field. As these new plants grew, their leaves
and outstretched branches shaded out the smaller plants below,
creating a different kind of habitat. Chipmunks and robins were
among the animals attracted to this new habitat.
||Stage 4. Over time, oak and hickory trees grew
tall and shaded out most of the shrubs, creating forest habitat
once again. Squirrels and wild turkey replaced chipmunks and robins.
Beech and maple seedlings grew much faster in the shade, and soon
stretched above the others. As the original oak and hickory trees
died and fell, the spaces they left in the forest canopy were
filled by beeches and maples growing up from below.
||Stage 5. More than 200 years after this forest
was first cleared for farming, it returned to beech-maple forest
again through the process of succession. For this location, beech-maple
forest is the "climax community" the association of
plants and animals that will remain stable until disturbed by
an outside force such as fire, wind, disease, or human activity.
of the world support different kinds of climax communities, including
deserts, prairies, and rainforests.
this understanding of succession to manage wildlife populations. The
endangered Kirtland's warbler, for example, will only nest in stands
of young jack pine trees. Periodic wildfires once maintained this
habitat, but when humans suppressed fires, Kirtland's warblers had
nowhere to nest and nearly became extinct. Today, in Kirtland's warbler
habitat areas, managers use clearcutting and prescribed burning to
prevent succession from occurring—to maintain the young jack
pine habitat that the warblers and other kinds of wildlife need to