Depth-driven responses of microbial residual carbon to nitrogen addition approaches in a tropical forest: Canopy addition versus understory addition - Kuang, Luhui (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Mou, Zhijian (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Li, Yue (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Lu, Xiaofei (Nanjing University of Information Science & Technology. School of Environmental Science and Engineering) ; Kuang, Yuanwen (South China Botanical Garden. Guangdong Provincial Key Laboratory of Applied Botany) ; Wang, Jun (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Wang, Faming (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Cai, Xi'an (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Zhang, Wei (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Fu, Shenglei (Henan University. College of Environment and Planning) ; Hui, Dafeng (Tennessee State University. Department of Biological Sciences) ; Lambers, Hans (University of Western Australia. School of Biological Sciences) ; Sardans i Galobart, Jordi (Centre de Recerca Ecològica i d'Aplicacions Forestals) ; Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals) ; Ren, Hai (South China Botanical Garden. Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems) ; Liu, Zhanfeng (South China Botanical Garden. Guangdong Provincial Key Laboratory of Applied Botany)