Passage I
A 1-hectare (10,000 m2) area of forest was equally divided into Plots X and Y. The herbaceous layer (all nonwoody plants ≤ 1 m tall) in Plot Y was then killed using an herbicide. Next, equal numbers of seeds from 5 tree species were evenly dispersed throughout both plots. Figure 1 shows, for each tree species, the seedling emergence (average number of seedlings per m2 that emerged from the forest floor) for each plot. Figure 2 shows, for each tree species, the percent of the seedlings that were surviving in each plot 1 yr after emergence. Figure 3 shows, for each plot, the percent distribution of the 5 tree species among those 1-year-old seedlings.
1. Which of the 5 tree species had no surviving seedlings 1 yr after emergence in the plot for which the herbaceous layer was undisturbed?
Your Answer is
Correct Answer is D
Explanation
The question is about surviving seedlings, so see figure 2 (the ordinate is percent seedling survival). The undisturbed herbaceous layer is also mentioned in the question stem, so refer to plot X. It can be seen from figure 2 that the yellow birch has no seeds on plot X