Question

8th grade science sensemaking smart starts
ls.8.2.1\tcarry out investigations to explain how changing biotic and abiotic factors such as food, water, shelter, and space affect populations in an ecosystem.

prompt #\tsmart start\tstudent response
1\treview the following table showing the annual rainfall and corresponding deer population numbers in a forest over the past five years. what trends can you identify, and how might changes in water availability influence the deer population?
\tyear\tannual rainfall (mm)\tdeer population
\t2019\t800\t150
\t2020\t950\t180
\t2021\t700\t140
\t2022\t600\t130
\t2023\t850\t160

Explanation:

Step1: Analyze Rainfall-Population Trend

Compare annual rainfall and deer population across years. When rainfall (800→950→700→600→850) increases, deer population (150→180→140→130→160) generally increases; when rainfall decreases, population decreases.

Step2: Explain Water Influence

Water (from rainfall) is abiotic. More water means more plants (food) for deer, supporting higher population. Less water reduces food, lowering population.

Answer:

Trend: Deer population generally increases with more annual rainfall and decreases with less.
Influence: Water (from rainfall) is abiotic. More water boosts plant growth (deer’s food), increasing deer population. Less water reduces food, decreasing population.