Interactions of Living Things The Environment

Ecology All organism, from the smallest bacteria to a blue whale, interact with their environment Ecology: the study of the interactions among organisms and their environment Abiotic factors: nonliving parts of the environment Biotic factors: living or once-living organisms in the environment

Abiotic Factors Examples of abiotic factors: water, sunlight, temperature, air, and soil These factors are important in determining which organisms are able to live in a particular environment

Ecologist study biotic and abiotic factors in an environment and the relationship among them. Many times, ecologists must travel to specific environments to examine the organisms that live there.                                                                                                                                        

Water All living things need water to survive The bodies of most organisms are 50 – 95% water More than 95% of Earth’s surface water is found in the oceans Saltwater environment in the oceans is home to a vast number of species Freshwater environments support thousands of types of organisms

Saltwater accounts for 97% of the water on Earth Saltwater accounts for 97% of the water on Earth. It is found in the seas and oceans. Only 3% of Earth’s water in freshwater

Light Light and temperature affect the environment The availability of sunlight is a major factor in determining where green plants live Algae live near the water’s surface where sunlight can penetrate Little sunlight reaches the forest floor, so very few plants grow close to the forest floor

Flowers that grow on the forest floor grow during the spring when they receive the most sunlight.

Temperature Temperature can determine which plants and animals can live in a region Some areas of the world have a fairly consistent temp. year round, but others vary Water environments throughout the world also have a widely varied temp. Plant and animal species found in the freezing cold Arctic, in the extremely hot water, and every temp. in betwee,

Air Although you can’t see the air that surrounds you, it has an impact on the lives of most species Composed of a mixture of gases Polluted air can cause the species in an area to change, move, or die off All species are affected by the weather in the area that they live

Air pollution can come from many different sources Air pollution can come from many different sources. Air quality in an area affects the health and survival of the species that live there.

Soil From one environment to another, soil can vary greatly Soil type is determined by the amounts of sand, silt, and clay it contains Different plants need different kinds of soil Soil affects every organism in an environment

Soil provides a home for many species of animal.

Biotic Factors Abiotic factors do not provide everything an organism needs for survival Organisms depend on other organisms for food, shelter, protection, and reproduction How organisms interact with one another and with abiotic factors can be described in an organized way

Levels of Organization The living world is highly organized Atoms – molecules – cells – tissues – organs – organ systems – organisms Biotic and abiotic factors also can be arranged into levels of biological organization Organism – population – community – ecosystem – biome – biosphere

Organism: An organism is one individual from a population.

Populations All the members of one species that live together make up a population EX. All of the catfish living in a lake at the same time make up a population Members of a population compete for food, water, mates, and space The resources of the environment and the ways the organisms use these resources determine how large a population can become

Population: All of the individuals of one species that live in the same area at the same time make up a population

Communities Most populations of organisms do not live alone They live and interact with populations of other types of organisms Groups of populations that interact with each other in a given area form a community Populations of organisms in a community depend on each other for food, shelter, and other needs

Community: The populations of different species that interact in some way are called a community.

Ecosystem Ecosystem is made up of a biotic community and the abiotic factors that affect it Ex. Coral reefs, forests, and ponds

Ecosystem: All of the communities in an area and the abiotic factors that affect them make up an ecosystem.

Biomes Scientist divide Earth into different regions called biomes A biome is a large region with plant and animal groups that are well adapted to the soil and climate of the region Many different ecosystems are found in a biome

Biome: a biome is a large region with plants and animals well adapted to the soil and climate of the region.

This map shows some of the major biomes of the world This map shows some of the major biomes of the world. What biome do you live in?

Biosphere The part of Earth that supports life is the biosphere Includes the top part of Earth’s crust, all the waters that cover Earth’s surface, the surrounding atmosphere, and all biomes The biosphere is only a small part of Earth

Biosphere: The level of biological organization that is made up of all the ecosystems on Earth is the biosphere.

Quiz What is an ecosystem? How are the terms ecology and environment related? Explain how biotic factors change in an ecosystem that has flooded.

Answers All of the communities in an area and the abiotic factors that affect them Ecology is the study of the interactions among organisms and their environment Organisms that do no live in water would die. Other water organisms might move into the ecosystem