Chapter 6 Biomes

6-1 How are organisms on Earth connected?

Connections in the Biosphere The biosphere is the part of Earth in which living things are found. All organisms share earth’s resources, such as water, air, and light. The study of how living things interact with each other and their environment is called ecology.

Organization of the Biosphere An environment includes both living and nonliving parts. A population is a group of individuals that belong to the same species and live in the same area. Every member of a population needs food, water, air, space, shelter, and other resources.

A community is a group of populations that interact with each other in a particular area. An ecosystem is a community of organisms living together along with the nonliving parts of the environment. An ecosystem can be as small as a crack in a sidewalk or as large as a forest.

Meeting the Needs of Organisms Abiotic factors are the nonliving parts of an ecosystem: Water Sunlight Temperature Soil Air

The amount of water in an ecosystem can limit the number of organisms it can support. Since plants need sunlight for photosynthesis, sunlight is important to all living things. The amount of sunlight an area receives determines the kind of plants that grow there. The temperature of an area also determines what organisms live there. Biotic factors are the living organisms in an ecosystem.

Adaptations Biotic and abiotic factors shape the communities that live in an ecosystem. All organisms in a particular ecosystem have adaptations that help them survive there. An adaptation is a characteristic that helps an organism live and reproduce in a particular environment.

What are Earth’s biomes? Chapter 6 Lesson 2 What are Earth’s biomes?

Climate and Biomes Similar communities occur in places that have similar climates and landforms. A biome is a large group of ecosystems with similar climates and organisms. Climate is the average yearly temperature and precipitation in an area.

A tropical rain forest has wet, humid conditions and long periods of sunlight that make it an ideal place for large trees and other plants to grow. Trees block some sunlight and help make different environments within the rain forest. Scientists estimate that at least two million species live in Earth’s rain forests.

Trees do not grow in cold climates, but you will find mosses and small shrubs. Grasslands bet about 60 cm of precipitation a year. Therefore very few trees grow there.

Characteristics of Biomes Climate is an important factor in determining which organisms can live in an area. Soil varies from place to place, and it plays an important role in what kinds of plants can survive in an ecosystem. Although similar biomes in different part of earth will share similar climate and organisms, there are differences.

Tropical Rain Forest The tropical rain forest contain more species than any other biome. More than half of the rain forests have been destroyed.

Deciduous Forest The most common plants are deciduous trees. Deciduous trees shed their leaves each year and then grow new ones. As the forest trees lose their leaves each year, the fall to the ground and decay. The soil is nutrient rich in a deciduous forest due to the decaying leaves that have fallen.

Taiga Conifers, such a fir, spruce, and hemlock, are some of the plants that have adapted to the poor soil and long cold winters of the taiga. The taiga is also called the boreal forest or coniferous forest.

Grassland Grasslands do not get enough rain to have large trees growing in them. The grasslands has some of the most fertile soil and is an excellent place for farming. Some of the largest animal on Earth live on grasslands including bison, zebras, rhinoceros, and giraffes.

Tundra The tundra has a permafrost which is a layer of permanently frozen soil just beneath the surface. The cold temperatures, high winds, and short growing season limit plant growth to short shrubs, grasses, mosses, and a few very short trees. Foxes, lemmings, hares, and caribou are a few of the common animals.

Desert All desert are not hot. Many deserts can be quite cool, especially at night. The characteristic that is common to all deserts is that they are dry. Desert plants include cacti and other plants that have short growth cycles. Many animals are active at night when the temperatures are cooler.