Article Soil Enzyme Activities in Pinus tabuliformis (Carriére) Plantations in Northern China Weiwei Wang 1, Deborah Page-Dumroese 2, Ruiheng Lv 3, Chen Xiao 1, Guolei Li 1 and Yong Liu 1,* 1 Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China; weiweiwang8893@gmail …