ecology
the study of how living and nonliving things interact. Living and nonliving things depend on each other.
terrarium
is a model of an ecosystem. Ecosystems include both living and nonliving things.
Nonliving part of your ecosystem
water, rocks air, light, and soil
Living part of your ecosystem
plants and animals
community
the living part of an ecosystem. Each ecosystem has its own community. A terrarium community can have small plants and animals. A desert community includes cacti and deadly scorpions. Woods community has deer, squirrels, trees, rabbits, moss, bushes, fern
population
is made of only one organism. Your terrarium ecosystem had populations of organisms such as snails, and earthworms.
habitat
each organism's home. The soil is an earthworm's habitat. A whale's habitat is the ocean. A termite's habitat is a termite nest.
What makes one ecosystem different from another?
water, temperature, soil, and sunlight. The types of plants and animals that live in a particular ecosystem depend on a combination of these things. For example, woodland forest has enough rich soil and enough water for many grasses to grow but does not h
water
A desert is very dry. Only a small number of species of plants and animals can survive with little water.
sunlight and temperature
Some plants, such as cacti, grow where there is little water but plenty of sunlight. The amount of sunlight in an ecosystem also affects the temperature. Cacti grow best in very warm temperatures.
soil
areas with soil rich in nutrients can support many plants. Few plants grow in areas with soil that does not have many nutrients.
Organisms change the environment
In all types of ecosystems, organisms cause changes. Most changes do not affect the ecosystem very much. When plants and animals move, eat, and grow, they are usually just doing their part to keep the system in balance.
Some changes can harm the environment
Too many animals in one area may use up all the food or water. Humans may harm the environment by building houses on forest or desert land. This causes animals to move.
Other changes improve and protect the ecosystem
Plants keep the soil in an ecosystem from eroding. Birds may eat insects that would harm plants in the environment. Humans protect animals by setting up wildlife preserves.
Tundra
Long, dark, and very cold winters. Few trees. Ground is frozen beneath the surface.
Taiga
Very cold winters, cool summers. More rain or snow falls than in the tundra.
Grasslands
Cold winters, hot summers. More rain or snow falls than in the taiga. Rich soil.
Mild forest lands
Mild winters and summers. Plenty of rain or snow. Trees lose their leaves in winter. Delaware, North Carolina
Desert
Very hot days all year. Dry, very little rain. Plants and animals adapted to conserve water. Cacti, snakes.
Tropical rain forest
Hot and rainy all year. Poor soil. Variety of plants and animals. Many trees, little sun.
Water Ecosystems - Saltwater shores
Many organisms live where the water level changes from high tide to low tide.
Freshwater rivers
Many habitats are along the shore and river bottom.
Freshwater lakes and ponds
Many habitats are at the shore, on the surface water, and under the water.
Open sea-surface
This area gets plenty of light. It is rich in nutrients and home to many populations.
Open sea-deeper down
Ecosystems change as the amount of light decreases with depth.
A community works like a team
Each member of the team has its own job to do. There are three different type of team members:
1. producers - make food
2. consumers - use the food that producers make or eat other organisms
3. Decomposers - break down wastes and the remains of other orga
producers - You can tell most producers by their green color. The color shows that their cells have chloroplasts. Chloroplasts are the cell's food factories. To make food, producers use water, carbon dioxide in the air and the Sun's energy.
Producers are the "energy capturers" of the world. they capture light energy from the Sun and transform it into food. Producers use only some of the food they make. The rest is stored. Other members of the community eat producers or organisms that have ea
Producers are important to many parts of the ecosystem.
- Without producers there would be no way for other organisms to survive. Consumers and decomposers would not have a valuable source of energy.
- Producers also affect nonliving parts of the ecosystem. Plant roots hold the soil in place. Other producers p
food chain
is the set of steps in which organisms get the food they need to survive. Producers, such as plants, make their own food. Consumers and decomposers must get food from producers or other consumers.
consumers
Organisms that eat food. Animals are consumers. So are some kind of one-celled organisms. Consumers in the terrarium may have included insects and frogs. To stay alive, consumers must get food from other organisms.
There are three types of consumers
herbivores - consumers that eat only plants
carnivores - consumers that eat only animals
omnivores - consumers that eat plants and animals
decomposers - in the terrarium may have included microorganisms such as bacteria and some kinds of fungi, and larger organisms such as worms and snails.
Decomposers have an important job. They break down living and dead matter into simple chemicals that they use for food. The chemicals left behind by decomposers are recycled, or used over and over again. Producers use these chemicals for making food. Mold
Both living and nonliving factors influence the decay process. Decomposers such as worms, crickets, bacteria, and fungi help. Nonliving things such as soil, dead leaves, and other decaying plant and animal materials also help speed the processes of decay.
A dead tree can decay with the help of fungi decomposers. Over time simple chemical substances are produced and used by other organisms. The soil becomes richer and new organisms grow, including plants. So, as organisms die and decay, new organisms are gr
natural fertilizers
the chemicals produced by decomposers. Fertilizers are made of decaying plants, animals, and animal waste. They add minerals to the soil and enrich the soil for plants.
Food web
Food chains show how energy is passed from the Sun to producers, consumers, and decomposers. In any ecosystem, food chains can overlap. Different food chains may include some of the same organisms. Several consumers may all eat the same kind of plant or a