Q:
What is an ecosystem?
Ecosystems are defined as communities
of plants, animals and microorganisms found within a particular area,
interacting with each other and with the environment. Hence, the term
"ecosystem" encompasses both the biotic and abiotic (living
and non-living) components of a particular environment. Ecosystems
are complex and dynamic entities that use energy, produce wastes and
recycle nutrients. All ecosystems, whether marine or terrestrial,
are interconnected. What occurs in one ecosystem affects the dynamics
of another. Collectively, all ecosystems make up the biosphere, or
zone of life, which occurs in the thin outer layer of the Earth's
surface.
In most ecosystems, energy from
the sun is the initial power source that promotes growth in plants
and algae. Plants are autotrophic, meaning they are self-feeding.
The process of photosynthesis allows plants to take in light energy
from the sun and convert it into the chemical energy stored in sugars
and other carbohydrates produced by plants. Because production by
plants forms the base of all food webs in an ecosystem, and provides
food for other organisms, it is also called primary production.
Thus, plants are the producers in ecosystems. Consumers cannot produce
their own food, so must rely on ingesting other organisms in order
to obtain their energy. Consumers that eat only plants are called
herbivores; carnivores eat only animals; and omnivores consume a
combination of both plants and animals. Decomposers, such as bacteria
and fungi, assist in recycling nutrients by breaking down the complex
organic molecules in dead plant and animal tissues into simpler
substances that can be made available for reuse.
Each time one organism consumes another, some of the energy from
the ingested organism is then taken up by the consumer. This transfer
of food energy from one organism to another is commonly referred
to as the food chain. Rarely, however, is this energy transfer a
simple, direct process. Rather, it can be highly dynamic and complex,
since most organisms eat more than one type of food and are therefore
involved in more than one food chain. The term food web more accurately
describes the complexity of food energy transfers between organisms
and the process of nutrient recycling within ecosystems.
Q:
What is a habitat?
A habitat is defined in general terms
as the specific place in an environment where an organism lives.
Terrestrial and marine environments each have distinct characteristics
that determine whether they can support specific organisms. A close
look at any area along the Florida coast reveals a number of different
habitats. In deep offshore waters, a unique Oculina reef
found nowhere else in the world runs from Ft. Pierce to Daytona.
Nearshore reefs composed of coquina rock and sabellarid wormrock
are quite common in some coastal areas. Along the barrier island
system in east central Florida, sand dunes along the shoreline abound,
which can be further subdivided into foredunes, dune crests, swales
and secondary dunes. Inland of the dune system lie the scrub zones
and maritime hammocks that have been built upon stable backdunes.
Beyond hammocks, the land begins to fall toward the Indian River
Lagoon where the mangrove fringe is located. Mangrove areas border
both the east and west margins of the lagoon along most of its length.
Within the lagoon itself are various submerged aquatic habitats
such as seagrass beds and oyster reefs, as well as the many spoil
islands which arose as the result of dredging in the lagoon. Past
the mangrove fringe are the fresh water swamps, hardwood hammocks
and upland forests that characterize interior Florida.
The Indian River Lagoon stretches approximately
156 miles along the east central Florida coast. Biodiversity in
the Indian River Lagoon is so vast due to both its diversity of
habitats and its unique geographical position. East central Florida
is fortuitously located in the transition area between the temperate
Carolinean Province to the north, and the subtropical Caribbean
Province to the south. Temperate species of plants and animals exist
in the Indian River Lagoon at the southernmost extent of their ranges,
while subtropical and tropical species exist at their northernmost
extents. Generally, the area around Cape Canaveral in northern Brevard
County is where vegetation patterns begin to shift from primarily
warm-temperate shrubs and trees, to more subtropical and tropical
varieties.
Report by: K Hill, Smithsonian Marine Station at Fort Pierce
Edited & Updated by: LH Sweat, Smithsonian Marine Station at
Fort Pierce
Submit additional information, photos or comments to:
irl_webmaster@si.edu
Page last updated: 15 July 2009 |
