Agro-forestry models and their economic benefits in the sandy region-Taking sandy region of Kaifeng City in Genan Province as an example Characteristics of farming-forestry-animal husbandry integrated ecosystem in Kaifeng sandy region Simulation alfalfa growth in Wulanbuhe sandy region A Study on the Relationship of the Shelter-forest Microclimate Effects on Man-made Oasis and Crops Production in Wulanbuhe Sandy Region Effect of Irrigation Methods and Quota on Morphological Characteristics of Alfalfa in Wulanbuhe Sandy Region Communities of Typical Sand Dune-fixed Plants in the Central Part of Otindag Sandy Region