The scientific study of how organisms interact with their environment
and all the other organisms that live in that environment.
All the living and nonliving things that interact in a particular area.
( Ecosystems can be as small as a pond or a large as a desert.)
The place where an organism lives and that provides the things the organism needs.
A single ecosystem might contain many habitats. Organisms live in different habitats because
they have different requirements for survival.
Each organism has a role to play in the habitat, a role which is referred to as its Niche.
The Niche an organism fills in a habitat is not limited to its place in
a food web. Plants provide nesting sites as well as food. Generally, no two species will fill exactly the same niche in a habitat
Organism- A single individual animal, plant, fungus or other living thing.
Population-All the members of one species in a particular area .
The maximum number of individuals in a population that an ecosystem can support
is called Carrying Capacity.
Community -Most ecosystems contain more than one type of organism.
A community is a group of different populations that live close enough together to interact.
One way they might interact is by using the same resources, such as food and shelter.
Biome-A biome describes in general terms the climate and types of plants found in similar places around the world.
Environmental factors that prevent a population from increasing.
Some limiting factors for populations are food, space and weather
conditions. ALSO, air, light and water.
limiting factors might be the number of other organisms of the same
population living in an area.
Biotic Factors- are the living parts of an ecosystem.
Abiotic Factors- are the nonliving parts of an ecosystem.
(Water, Sunlight, Oxygen, Temperature, Soil)
All living things need water.
Plants need it and sunlight to
carry out photosynthesis,
Animals need it to digest
food and release energy stored in food.
Ecosystems with a lot of water can
support a large number of plants, and these plants can support a large number
of different types of animals.
It’s necessary for photosynthesis.
If the plants don’t get it
they can’t survive.
ofthe sunlight and amount of sunlight
will determine the type of
plants that can survive
No plants means no food for other
It also warms the Earth’s surface.
It’s also a factor in ocean ecosystems because the deeper the water, the less light will be available.
In shallow water near the shore there will be more plant growth and therefore more food than in deeper parts of the ocean.
Most living things require oxygen to carry out their
The temps that are typical of an area determines the types of organisms that can live there.
Soil is a mixture of small rock and mineral particles, nutrients, air, water and the decaying remains of living things. The type of soil influences the
kind of plants that can grow in an ecosystem. Some animals use the soil as a home.
Billions of microscopic organisms such as bacteria may also live in Vthe
Matter Cycles Through Ecosystems
Cycle- A series of events that happens over and over again.
The Water Cycle
Water is stored in lakes, rivers and oceans. Water is
found underground in the spaces between soil particles and cracks in
rocks. Water is stored in glaciers and polar ice sheets.
Water is also part of the bodies of living things.
Water isn’t just stored. It’s constantly moving among these areas. This movement ofwater through the environment is called the Water Cycle. The Hydrologic Cycle (Water Cycle) is also responsible for purifying Earth's water supplies. The process of Evaporation occurs when liquid water turns to water vapor. This happens when heat is added to liquid water. When water evaporates, ONLY the H2O turns to water vapor.
The Carbon Cycle
(impurities, salt, whatever...) is left behind. Water vapor
returns to liquid state when it LOSES HEAT. This process is
called Condensation. Finally, the liquid, or frozen water falls to the Earth as Precipiation. This precipitation may flow over Earth's surface as Surface Runoff.
Surface Runoff often follows the same path, and when this
happens, it forms Rivers and Streams. Precipitation may also sink
into the pore spaces found between particles of soil. When this
happens, it's called Groundwater.
Both Surface Runoff and Groundwater eventually makes it way back
to the sea, where it will eventually be evaporated into the atmosphere
once again. Perhaps instead it evaporates somewhere along the way
back into the atmosphere, perhaps it's used by other living
things along the way, or perhaps used by plants and returned to the
atmopshere through Transpiration. This
process has been going on since water first formed on Earth,
nearly five billion years ago! Think of it...the water that you
use today, has undoubtedly been used many, many times before, by many,
many creatures which existed on Earth before you came along.
Wouldn't it be interesting to know what, or who, previously used
those very same water molecules that you just consumed? You're
not the first to use those same molecules, and you certainly won't be
the last. With every sip you take, you're part of a very old
series of events indeed. Events that have gone on, and will
continue, well beyond the short number of years you're here on Earth.
All living things on
Earth are built with the Carbon atom. We're carbon based life
forms! This important atom called Carbon is also recycled here on
Earth. If it were not, you wouldn't be here reading this right
now, since all the carbon would have been used up long, long ago.
The carbon cycle involves two important processes. Photosynthesis
and Respiration. Photosynthesis is the process that green plants
use to make food. Remember that the major difference between
plants and animals is just that...Plants can make their own food using
the process of Photosynthesis. Animals have to find their food
and eat it. Using sunlight, and some water, and a few compounds
like Chlorophyll, plants are able to basically break a CO2
molecule into a Carbon atom, which is used to build starches and sugars
by the plant, and a pair of Oxygen atoms, which are pretty much given
off as a waste product. Good thing for us. Animals, like
Lions and Tigers and Bears and I, eat food made of long chains of
Carbon Atoms and we breathe in 0xygen. We use the Oxygen to burn
the Carbon-based food we consumed, and we get the energy we need to run
our bodies. This process, called Respiration, provides the energy
we need, and the Carbon atoms are now bonded to the Oxygen atoms, in
the form of Carbon Dioxide . The Carbon Dioxide is exhaled by
animals like us, as a waste product. This same Carbon Dioxide is
then absorbed by some lucky, hungry, photosynthesizing plant somewhere.
The cycle goes on and on, forver and ever. It always has,
and it always will, so long as there are plants and animals here on
Carbon is also stored
underground. Remains of plants and animals buried for millions of
years decay slowly and change into fossil fuels such as coal and oil.
The Nitrogen Cycle
Nitrogen is a gas quite important to you
and me, and all the other living things on this Wonderful World.
Nitrogen is used to make Proteins, which are substances used for cell growth and repair. Since
we're mostly protein, that makes Nitrogen pretty important. The
problem is that the Nitrogen in the atmosphere isn't useable by our
bodies. This is where the Nitrogen Cycle comes in. You
might think of the Nitrogen Cycle as the continuous movement of Nitrogen from the atmosphere, to the soil, to living things, and then back to the air or soil. A similar process also takes place in Earth's oceans as well. On land, bacteria in the soil, called Nitrogen-fixing Bacteria, convert the atmospheric Nitrogen into substances called Nitrates.
Plants are able to use these Nitrates to build plant proteins in
their bodies. Animals like you and me, and lemurs, must either
eat plants, or eat something that eats plants, to get these same
substances into our bodies. When plants or animals die, their bodies
are broken down by another bacterial process, called Decay or Decomposition. Decay returns the Nitrogen to the air or the soil, to become a part of the Nitrogen Cycle once again.
Energy Flows through Ecosystems
Energy from the sun is a precious thing. Every living thing needs energy, and living
things can be put into one of three categories, based upon how they
get the energy that they need.
Organisms that capture energy and store it in food as chemical energy.
Producers make energy available to all other living parts of the ecosystem.
Plants, algae and certain other microorganisms.
Producers can make their own food.
Sunlight usually, but not always, provides the energy to the producers.
Organisms that get their energy by eating, or consuming, other
organims. Consumers are usually classified by what they eat.
Herbivore-eat only plants
Carnivore-eat only animals
Scavenger-a carnivore that feeds on the bodies of dead organisms.
Omnivore-eats both plants and animals
Organisms that break down dead plant and animal matter into simpler
compounds. They break down waste and dead organisms and return the raw
materials to the environment. (Which can be then used by other organisms)
Bacteria and Fungi are the major groups of decomposers.
Food Chains and Food Webs
A series of events in which one organism eats another and
obtains energy. The first organism in a food chain is always a producer.
A food chain describes the feeding relationships between a producer and a
single chain of consumers in an ecosystem.
Consists of many overlapping food chains in an ecosystem.
A model of the feeding relationships between many different
producers and consumers in an ecosystem.
Both food chains and food webs show how different organisms receive their energy.
They also show how different types of organisms depend on one another.
If one organism is removed, it may affect other organisms in the ecosystem.
The Energy Pyramid
Another way to picture the flow of energy in an ecosystem is to
use an energy pyramid.
It’s a model that shows the amount
of energy available at each feeding level of an ecosystem
Interactions among living things.
is the struggle between individuals or
different populations for a limited resource.
Competition may occur within the same species.
Competition within species often occurs during the mating season.
may also occur between members of different species.
Competition doesn't happen between ALL populations that share the
Many populations can coexist in a habitat.
Different species can live together without causing harm to one
Many different species of plants coexist in a forest. Trees can
live side by side and still
have enough water,
nutrients and sunlight to meet their needs.
Not all relationships involve competition. This is an interaction in
which organisms work in a way that benefits them all.
This is when one organism eats another organism. Pretty simple. The one doing the eating is the
The one getting eaten is the "Prey". Both predators
and prey may
have various adaptations that allow them to be better at what they do.
This is the relationship between two different species who live together in a close relationship.
There are three forms of Symbiosis.
Mutualism-both species benefit
-one species benefits, the other isn't affected.
a small partner harms a much larger host. The parasite
benefits, the host is harmed. Parasites are
often tiny organisms
that feed off, and weaken,
In the end, it all boils down to