Habitat – The place in an ecosystem where an organism prefers to
live.
Q. What are the major needs of an organism’s habitat?
A. Food, water, cover, and space.
 Changes in habitat can positively or negatively affect the
population of a species.
Examples
Ruffed Grouse- Requires brushy forests for cover and food. Most
of Pa’s forest were logged (cut down) 80 to 100 years ago. They
grew into brushy forest allowing grouse populations to increase.
Forests are now maturing reducing cover and food causing
populations to decline. Land development has also reduced
populations
Eastern Bluebird – Small songbird that nest in cavities of trees
and wooden fence posts. They prefer open fields and farmlands to
feed on insects. Populations have declined since WWII due to
wooden posts being replaced by steel and loss of farmland
(pesticides). Back yard nesting boxes have recently helped the
population.
White-tailed Deer – Deer are grazing and browsing animals of the
forest and field. The population has increased due removal of its
predators over 100 years ago. Deer have learned to live near people
and benefits from edge effect and landscaping. Deer are
overpopulated and have removed much of the forest shrub layer.
Population is controlled by hunting
Edge – a place where two ecosystems meet. A greater variety of
organisms can exist in overlapping ecosystems.
Example: forest and a field
Benefits of edge to wildlife
Edge provides more food and cover for many animals
Ex.
Negative impacts to wildlife
An edge may cut through and limit (fragment) a habitat.
Example: A highway through a forest may keep woodland species
from crossing. Edge may also increase competition (brown headed
cowbird and warblers)
Community – a group of organisms that interact with each other
in an ecosystem
EX. Pond community – algae, insects, fish , frogs, etc.
Community- A set of interacting populations.
Example – A forest community contains all living populations
(trees, shrubs, wildlife, microbes, etc.)
Species – organisms that are similar in structure and behavior that
breed to produce fertile offspring