Final answer:
The carrying capacity of the area to support deer decreased between 1925 and 1930 due to hunting and forest management activities.
Step-by-step explanation:
The most likely reason that the carrying capacity of the area to support deer decreased between 1925 and 1930 is due to hunting and forest management activities.
As mentioned in the provided information, deer populations have undergone population declines in the last centuries due to hunting and forest management. In Fennoscandia, cervid species like moose and roe deer are maintained in artificially large numbers for recreational hunting purposes, which can result in outbreaks of parasites like the deer ked.
Hunting and forest management can directly impact the deer population and their habitat, leading to a decrease in the carrying capacity of the area to support deer.