Population Graphs and Ecological Succession

HS-LS2-8 Which definition best explains pioneer species?

• A relationship where both species benefit each other
• Species that are predominant early in succession
• Number of species in an area

HS-LS2-8 Which option best describes a primary succession?

• Development of a community in area which has not supported life before
• Replacement of a species after a disaster
• Volcanic eruptions, forest fire, flood, or drought.

HS-LS2-8 Which vocabulary word best represents the image?

• Primary succession
• Climax community
• Secondary succession

HS-LS2-8 Which vocabulary word best represents the image?

• Primary succession
• Symbiosis
• Secondary succession

HS-LS2-2 Consider the population graph of oak trees above. Sometime between the years of 2009 and 2012 a fire broke out and killed several trees. What year did this fire occur?

• 2009
• 2011
• 2012

HS-LS2-2 Now consider this population graph. The acorn birds feed on the acorns of the oak tree. Why did their population drop after the population of oak trees dropped?

• The acorn birds' population dropped after the fire because they were damaged by the fire and their young nests were killed causing a delay in population decline due to the losses of one generation.
• The acorn bird population declined after the oak trees because the acorn birds lost trees to build their nests in.
• Since the acorn birds depend on the acorns for survival, they experience a delay in population decline as at the time of the fire their population was supported by the acorns. Still, then afterward their population shrinks as there is less food available.

HS-LS2-2 American persimmon trees are usually able to tolerate temperatures down to 32 degrees Celsius. According to this information and the graph attached, in which years were weather conditions not favorable for persimmon trees?

• 2012 - 2013
• 2009 - 2010
• 2011 - 2012

HS-LS2-2 Why would the introduction of wolves to this ecosystem cause the populations of fish and grass to increase?

• The introduction of wolves causes the population of grass to increase because they eat grazing animals. This allows more grass to grow, which is good for the ecosystem.
• The introduction of wolves is not what caused the population of fish to increase because they are predators. Therefore, there must be another reason why the population of fish increased when wolves were introduced.
• The introduction of wolves will help to improve the quality of grass, thereby increasing its population and providing food to the fish, which increases its population as well.