Ecosystems and Environments

Students will explore how living and nonliving components in the environment help populations and communities survive. Students will be introduced to the impact of environmental changes which will prepare them for more rigorous concepts in ecology in fifth grade

Key Concept 1: Environments have specific physical characteristics that provide food, water, air, or protection to populations and communities in an ecosystem.

Every environment (an organism’s surroundings) is a result of a delicate balance of living elements (organisms) and nonliving elements (objects, landforms, weather, and climate). An ecosystem is a community of living and nonliving things in their natural environment. In order for any population (living things that belong to the same group in the same area) or a community (group of different populations sharing an environment) to survive (stay alive), the living and nonliving elements must provide basic needs: food, water, air, and protection. Any adjustment to any of these factors can result in a dramatic change in an environment’s appearance or composition. Many influences on an environment can come from nature itself. Plants and animals must respond to changes in the ecosystem, or they can perish (die). Students will explore a variety of ecosystems represented on the map below:

Key Concept 2: Changes to an environment can affect whether certain organisms can survive in that ecosystem.

Plants and animals respond to changes from very different sets of living and nonliving elements depending on the ecosystem in which they live. For example, winter and summer months look very different in the far north tundra of North America. In July, it is common to see lots of greenery and animals roaming and grazing for food. However, in January, the ecosystem is frozen and quiet as many animals migrate to warmer locations. In forest ecosystems, summer brings warmth (nonliving element), greenery, and an abundance of insects (living element), and winter produces chilly weather (nonliving element), and the grass and plants become brown and dormant. Temperature changes can have powerful effects on living organisms in ecosystems. It is common for some animals to react to the sudden changes in temperature by hibernating after finding a safe place to hide from predators and the harsh weather.

Nature is not the only thing to cause changes to an ecosystem. Living organisms can also be responsible for changes within an environment. For example, when a population of beavers builds a dam, it can create a body of water like a pond or lake. This body of water then attracts other species of animals because of the increase in availability of freshwater. Also, the species that typically thrive in a pond of lake begin to grow in numbers and thrive in this newfound body of water.

The physical characteristics of an environment (nonliving element) can also determine the suitability for life of organisms. The high, craggy mountains of forest ecosystems in the northwestern United States are ideal habitats (animal homes) for mountain goats, whereas grassland ecosystems of the prairies are the environment of choice for the pronghorn antelope.

Key Concept 3: Environmental changes, such as floods, droughts, or fires, will cause some organisms to perish or move, while permitting other organisms to thrive.

Rapid changes to an environment are those that happen quickly. Some examples of rapid changes include hurricanes, floods, earthquakes, a volcano erupting, etc. Hurricanes bring high winds and huge amounts of water. When water from the ocean crashes onto land, the living organisms that typically survive in freshwater are threatened and may not survive. Living organisms have two outcomes that face them when they are hit by a rapid change to their ecosystem. First, if they are capable, they can migrate to escape the harmful conditions. If that is not an option for the organism, it may die. Nature often finds a balance when environments change; some organisms may die, while others find an opportunity to survive.