Science - 2018-19

LS.6 c - Relationships between Ecosystems

The student will investigate and understand that organisms within an ecosystem are dependent on one another and on nonliving components of the environment. Key concepts include

c) complex relationships within terrestrial, freshwater, and marine ecosystems.

Bloom's Levels:  Analyze; Understand

Adopted: 2010


  • Ecosystems are composed of biotic and abiotic components and are complex interconnected, systems.
  • Both human activities and natural events can have major impacts on the environment.

  • I can identify and explain the similarities and differences between life on land and in water.


  • An ecosystem is made up of the biotic (living) community and the abiotic (nonliving) factors that affect it. The health of an ecosystem is directly related to water quality.
  • Abiotic factors determine ecosystem type and its distribution of plants and animals as well as the usage of land by people. Abiotic factors include water supply, topography, landforms, geology, soils, sunlight, and air quality/O2 availability.
  • Human activities can alter abiotic components and thus accelerate or decelerate natural processes. For example, people can affect the rate of natural erosion. Plowing cropland can cause greater erosion, while planting trees can prevent it. Flood protection/wetland loss is another example.
  • A watershed is the land that water flows across or through on its way to a stream, lake, wetland, or other body of water. Areas of higher elevetions, such as ridgelines and divides, separate watersheds. 
  • The three major regional watershed systems in Virginia lead to the Chesapeake Bay, the North Caroline sounds, or the Gulf of Mexico.
  • River systems are made up of tributaries of smaller streams that join along their courses. Rivers and streams generally have wide, flat, border areas called flood plains, onto which water spills out at times of high flow.
  • Rivers and streams carry and deposit sediment. As water flow decreases in speed, he size of the sediment it carries decreaes.
  • Wetlands form the transition zone between dry land bodies of water such as rivers, lakes, or bays. Both tidal and nontidal wetlands perform important water quality functions, including regulating runoff by storing floo dwaters; reducing erosion by slowing down run-off; maintaining water quality by filtering sediments, trapping nutrients, and breaking down pollutants; and recharging groundwater. They also provide food and shelter for wildlife and fish and nesting and resting areas for migratory birds.
  • Estuaries perform important functions, such as providing habitat for many organisms and serving as nurseries for their young.
  • The Chesapeake Bay is an estuary where fresh and salt water meet and are mixed by tides. It is the largest estuary in the contiguous United States and one of the most productive.
  • Water quality monitoring is the collection of water samples to analyze chemical and/or biological parameters. Simple parameters includ pH, temperature, salinity, dissolved oxygen, turbidity, and the presence of macroinvertebrate organisms


In order to meet this standard, it is expected that students will

c)  identify examples of interdependence in terrestrial, freshwater, and marine ecosystems.

a, b, c, d)  design an investigation from a test table question related to food webs. The investigation may be a complete experimental design or may focus on systematic observation, description, measurement, and/or data collection and analysis.

analyze and critique the experimental design of basic investigations related to food webs.


ecosystem, producer, consumer, decomposer, food chain, food web, energy pyramid, herbivore, carnivore, omnivore, scavenger, carbon cycle, nitrogen cycle, water cycle, terrestrial ecosystem, marine ecosystem, freshwater ecosystem

Updated: Jun 29, 2018