10. Models of Reforestation for Soil Erosion Control in the Hilly Region of the Middle and Lower Reaches of the Yangtze River

In order to reforest on extremely eroded and degraded red soil sites under harsh conditions, many measures were carried out, such as choosing the appropriate species with strong stress resistance, combining biological and engineering measures, digging 750–1,500 fish scale-shaped pits per hectare and bamboo stem-shaped trenches, and preparing level terrace sites as well as establishing a rational structure and adopting advanced afforestation techniques (ABT rooting powders, using seedling containers, good provenance, high-density and multi-species reforestation, and digging holes for fertilization). One example of the three-dimensional configuration of trees, shrubs, and grasses of the reservoir area in the hilly red soil region showed that in sites of bicolor Lespedeza (Lespedeza bicolor) intercropped with slash pines (Pinus elliottii) after 10 years, the content of organic matter in the soil, total N, and P increased by 87.95, 36, and 40.91%, respectively, compared with the control area. On the hilltops and the upper parts of steep slopes in the reservoir area, forests were planted to conserve soil and water, with slash pine and red pine as main tree species. Meanwhile, measures were adopted by closing the hillsides to use in order to cultivate forests. The “stereoscopic” management model includes the fruit–grass (farming)–animal–biogas–fish model and the fruit–feeds–animal–biogas model. In the low hilly areas, the agroforestry management models were used, such as the so-called fruit–green manure–economic crop model, fruit–grass–economic crop model, the virtuous fruit–Amaranthus–pig–biogas–fruit cycle model, tree–tea compound model, and forest–herb management model.