The study looked at how desertification affects the soil seed bank in the Tarim River area. They found that as the land becomes more desertified, the number and variety of seeds in the soil decrease. Most seeds are found in the top 2 cm of soil. Areas with extreme desertification have more annual herbs, while areas with less desertification have more perennial herbs and shrubs. This means that as the land becomes more desertified, it becomes harder for natural vegetation to grow back on its own.