Soil erosion is a big problem in the upper and middle Yellow River area in China. Scientists studied how soil conservation helps protect the land. They used maps and data to see how much soil was saved by plants and trees. They found that in 2000, 7.22 billion tons of soil were saved each year, and by 2010, it increased to 10.19 billion tons. Forests were the best at saving soil, especially on steep slopes. Overall, 90% of the soil that could have been eroded was kept in place. Restoring vegetation helped a lot in improving soil conservation in the area.