Final answer:
Climate, soil conditions, and human activities dictate the location of tree species in Southern Arizona.
Step-by-step explanation:
The location of tree species in Southern Arizona is dictated by various factors including climate, soil conditions, and human activities.
Climate is a key factor as different tree species have different temperature and precipitation requirements. For example, saguaro cacti are adapted to hot and arid conditions, while pine trees prefer cooler and moist areas.
Soil conditions also play a role, as certain tree species require specific soil types and nutrient availability. Additionally, human activities such as land use changes and introductions of non-native species can impact the distribution of tree species.