It´s any water-based environment in which plants and animals interact with the
chemical and physical features of the environment.
Aquatic ecosystems are generally divided into two types:
* Freshwater ecosystem * Marine ecosystem
They cover over 70 percent of the earth's surface. Oceans, estuaries and coral reefs are
the various kinds of marine ecosystems.
Oceans are large salt-water bodies
connected across the earth. The ocean floor is
made up of shelves, plains and mountain
ranges. There are currents moving water
between different oceans. Waves and tides are
also ocean movements.
The place where fresh and salt-water meet
are called estuaries. This is a unique
place where two habitats come together.
Coral are polyps that live together in big groups, fixed to rocks. As they grow they
generate a kind of skeleton common to the whole colony. These skeletons grow very bib
and are called coral reef. However they grow very slowly over time. In fact, an inch of
coral reef takes nearly 100 years to grow! These places are a true paradise but they are
also very fragile.
They cover less than 1 percent of the earth and are subdivided into streams, rivers,
ponds and lakes.
Lakes are large bodies of freshwater surrounded by land, while ponds are smaller
bodies of water surrounded by land.
Rivers and streams are moving bodies of fresh water which usually originate in
mountains and come from melting ice or ground water and eventually terminate in
Terrestrial ecosystems are land-based ecosystems.
They range from the coldest places on earth to the hottest deserts found around the
equator. Each ecosystem is inhabited by species of plants and animals that have
evolved to thrive in them.
Terrestrial ecosystems are generally divided into 4 types:
- Coniferous forest
- Deciduous forest
Trees are the most important living things in a Forest. Trees provide food and shelter for
Coniferous forest: the one that has trees
that reproduce by dropping cones. They
are adapted to the cold weather.
Deciduous forest: They do not bear cones, they
contain seeds. They lose their leaves ones a year
when the weather turns cold. The weather tends
to be moderate.
Rainforests: They are filled with millions of
plants and animals. They are located near the
equator with lots of rain. This is known as the
Grasslands are big open spaces. Tall grass is the most characteristic feature, there are
not many bushes. Trees are found only by rivers and streams. The grassland seems like an
endless ocean of grass. Large animals, such as zebras, gazelles or antelopes, graze here:
that is, they eat the grass. It´s also known as Savannah.
Deserts are known to be hot, dry biomes. But there are also "cold" deserts. In these
deserts the nights are very cold, especially in the winter. As there is little rainfall, few
types of plants exist. Many of the animals live underground for much of the day. They
adapt to the heat by hiding under rocks when the sun is out.
How cold is cold? The Tundra ecosystem is at the top of the world -- around the
North Pole! Tundra is a place too cold for many animals or plants to survive. Often the
land is covered with snow most of the year, with much of the ground frozen. The
summer season is very short and many animals hibernate to survive the cold winter.
They combine both terrestrial and aquatic ecosystems. They can be:
Wetland: Seasonal wetlands are
flooded in the winter and begin to dry
out in the summer. The moisture
content of these biomes changes
seasonally. Rains arrive in the winter
and begin to fill the area with water.
With the arrival of water, insects,
reptiles, birds, and small mammals
populate the wetlands. As spring
arrives, the plants in the wetlands begin
to grow and bloom, providing an
additional food sources for the
residents. As summer approaches,
seasonal wetlands begin to dry out. The
green colors of spring turn to tan and
the populations change as some small
animals move deeper into the muddy
Coastline: The coast is where the land meets the
sea. Coastal life must be adapted to environmental
factors that grade from one extreme to another,
especially from wet to dry; wave action; and particle
sizes of bottom materials. Because these zones are
close to land, there are certain related plants and
animals that have adapted to these conditions. This
zone is also one of the most important for humans.