Question

questions 1 through 3 refer to the following.
based on the data shown in the graph, when would the species richness of the ecosystem
have been the lowest?
a before the volcanic eruption occurred
b one to four years after the volcanic eruption
c four to ten years after the volcanic eruption
d ten to fourteen years after the volcanic eruption

Explanation:

Step1: Analyze the graph

The graph shows the total number of plant species present over the years. The volcanic eruption is marked on the graph.

Step2: Determine the time period with lowest species richness

After the volcanic eruption, the number of plant species is lowest in the initial years. As time passes, the number of species increases. Looking at the options:

• Option A: Before the eruption, species richness was higher (as per the graph before the 'Eruption' mark).
• Option B: One - to - four years after the eruption, the number of species is at a low point (the graph shows a steep decline just after the eruption and starts to recover a bit later).
• Option C: Four - to - ten years after, the number of species has started to increase more compared to the one - to - four - year period.
• Option D: Ten - to - fourteen years after, the number of species is even higher.

Answer:

B. One to four years after the volcanic eruption