Final answer:
The number of square kilometers needed to support one deer is contingent on ecological factors like available resources, carrying capacity, and human activities. It also depends on the habitat health and balance between natural population growth and sustainable harvesting. Exact figures require local conservation priorities and understanding species-area relationships.
Step-by-step explanation:
To determine how many square kilometers are needed to support one deer, we must consider various ecological factors, such as available resources, the carrying capacity of the environment, and the impact of human activities. In a meadow ecosystem with a primary producers' biomass of 1500 kg/km², if developers halve this biomass and remove species like rabbits and deer, it would likely result in a significant ecological shift and potentially a reduction in the carrying capacity for deer. Moreover, when assessing the impact of hunting on deer populations, we note that in some countries, large numbers of deer can be harvested sustainably, while in others, even a small number of harvested deer could lead to population declines.
If we use the example given with 80 deer captured, tagged, and released, and later, 100 deer are captured with 20 being already marked, we could estimate the population size using specific ecological models. However, translating these large-scale insights to the local level, where conservation takes place at tens of km², is more complex. An understanding of species-area relationships is crucial, as shown by a typical species-area curve, which indicates that a 90 percent reduction in habitat reduces the number of species by about 50 percent. Therefore, the square kilometers required to support one deer would depend on these conservation considerations, the existing deer population, food availability, habitat health, and the balance between growth and sustainable harvesting.