Ecosystem - STANDARDS

Natural Hazards

Students in grades 5 through 8 should develop an understanding that:

Internal and external processes of the earth system cause natural hazards ó events that change or destroy human and wildlife habitats, damage property and harm or kill humans. Natural hazards include earthquakes, landslides, wildfires, volcanic eruptions, floods, storms, and even possible impacts of asteroids.

Individuals can use a systematic approach to thinking critically about risks and benefits intrinsic to any activity/undertaking/enterprise. Examples include applying probability estimates to risks and comparing them to estimated personal and social benefits.

Important personal and social decisions are made based on perceptions of benefits and risks.

 Life Science

The number of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantity of light and water, range of temperatures and soil composition. Given adequate biotic and abiotic resources and the absence of disease or predators, populations (including humans) increase at rapid rates. Lack of resources, as well as other factors, such as predation and climate, limit the growth of populations in specific niches in the ecosystem.

A population consists of all individuals of a species that occur together at a given place and time. All populations living together and the physical factors with which they interact comprise an ecosystem.

Millions of species of animals, plants and microorganisms are alive today. Although different species might not look alike, the unity among organisms becomes apparent from an analysis of internal structures, the similarity of their chemical processes and the evidence of common ancestry.