Global pattern of leaf litter nitrogen and phosphorus in woody plants Hongzhang Kang, Zaijun Xin, Björn Berg, Paul J. Burgess, Qunlu Liu, Zhicheng Liu, Zhaohua Li and Chunjiang Liu Ann. For. Sci., 67 8 (2010) 811 Published online: 29 October 2010 DOI: 10.1051/forest/2010047