Changes in climate throughout our planet have created changes in our environments, one of them being a rise in the amount of arid land covering Earth's surface. As humans grow increasingly likely to find themselves in desert locales, where less than 50 centimeters of rain falls each year, it becomes more important to understand the challenges to ecological stability a desert environment faces, many of which are exacerbated by human activity.
Although deserts exist in hot or cold environments, they are all characterized by the small amount of precipitation they receive annually. Because trees and grasses with roots that might trap any rainfall generally are not widespread throughout deserts, desert ground retains little water, making water scarce. Humans who come to live in deserts use this resource and also alter ground cover by removing plants while developing cities and towns. This loss of plant life can leave even less water in the soil and lead to soil erosion, creating further obstacles for plants in taking root.
Decreased Soil Quality
Yet water scarcity is not the only factor that can result in soil degradation. Deforestation, overcultivation of crops, and, in the case of China's Gobi Desert, overgrazing of livestock all have led to the desertification of lands or reduced the quality of existing desert soil by depriving the soil of sources of the nutrients that support life. Responsible irrigation and cultivation practices, however, have been shown to improve the nutrient content (and water retention) of desert soil.
Poor Air Quality
A windstorm can heave sandy soil into the air, another way of stripping a desert locale of vital soil nutrients. Besides affecting soil quality, though, dust storms can make breathing difficult and even obscure the sunlight necessary for plant life to thrive. In cities such as Tucson, Arizona, urban development unearthed fungal spores that infest lung tissue and cause a condition known as “valley fever,” degrading the health of the population while introducing dormant species back into the environment.
Changes to desert habitats may make it difficult for native species to survive. Additionally, established species may face threats from organisms newly arrived in the desert that are better suited to the climate and the environment. These species may migrate to the desert naturally, or they may be brought even unintentionally, by humans who travel there. Either way, they may compete with the established species for resources, presenting another threat to the delicate balance of desert ecology.