Effects of Stand Density on Tree Growth, Diversity of Understory Vegetation, and Soil Properties in a <i>Pinus koraiensis</i> Plantation oleh Abdul-Qadir Iddrisu, Yuanqin Hao, Hamza Issifu, Ambachew Getnet, Nazmus Sakib, Xiubo Yang, Mutaz Mohammed Abdallah, Peng Zhang