Why a species might not be able to expand its range?

A species might not be able to expand its range due to various factors, including environmental limitations such as temperature, humidity, or soil type that are unsuitable for its survival. Additionally, competition with other species for resources, predation, or disease can hinder its ability to establish in new areas. Dispersal barriers, such as mountains or rivers, and human activities like urbanization and habitat destruction can also restrict range expansion. Lastly, a lack of genetic diversity may impede adaptability to new environments.