Answers to Hone Your Problem-Solving Skills Questions

1. In 1982, the Pumice Plain had no surviving species, while the reference area had the highest species richness (five species). The blowdown and scorch zones both had intermediate species richness (three species).

2. Small mammals recovered in the two least disturbed successional habitats (blowdown and scorch zones) but not in the Pumice Plain. The pattern of species richness seen in the blowdown and scorch zones was likely due to their being secondary successional communities and thus having more resources available to them after the eruption. In the primary successional community of the Pumice Plain, the habitats and resources were nonexistent and had to be reestablished over time. Thus, it makes sense that this community could not support more than one small mammal species.

3. This suggests that the deer mouse has a life history that allows it to live in primary, secondary, and climax successional communities. It is likely able to disperse widely, grow quickly, and reproduce often—all characteristics of an early successional, pioneer species. The deer mouse is also likely to be an opportunistic and generalist species, living in a variety of habitats and feeding on a variety of food items.

4. It may be that some small mammal species were affected by the eruption, even though the trapping site was 21 km away from the mountain. Over time, these species recovered and were present in the reference community. In addition, it may be that the researchers did not trap individuals of a particular species some of the years, thus underestimating species richness. Alternatively, it may be that the animals became habituated to the traps because they contained bait. This could have resulted in individuals of rare species being caught more often over time.