The study looked at why sandy desert areas in the Horqin Region of China have expanded and then reversed over the past 50 years. They found that both climate change and human activities are major factors driving this process. Climate changes, like temperature and rainfall patterns, directly affect desertification, while human activities, such as farming and overuse of land, also play a big role. Human actions can speed up desertification by destroying natural vegetation and increasing soil erosion. However, with proper land use and prevention measures, humans can also help reverse desertification. In the end, sandy desertification in this region is mainly caused by human activities like over-cultivation and over-grazing.