Original article

Global pattern of leaf litter nitrogen and phosphorus in woody plants

¹ School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240, P.R. China
² College of Resources and Environmental Sciences, Hubei University, Wuhan 430062, P.R. China
³ Dipartimento Biologia Strutturale e Funzionale. Complesso Universitario, Monte S. Angelo, Via Cinthia, IT-80126 Napoli, Italy
⁴ Department of Forest Ecology, University of Helsinki, Latokartanonkaari 7, 00014, Finland
⁵ School of Applied Sciences, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
⁶ Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, People’s Republic of China, Dongchuan Rd. 800, Shanghai 200240, P.R. China

^* Corresponding author: chjliu@sjtu.edu.cn

Received: 14 July 2009
Accepted: 17 March 2010

Abstract

• Forest ecosystems exert an important influence on global biogeochemical cycles. A global dataset of nitrogen (N) and phosphorus (P) concentrations in leaf-litter of woody plants was compiled from the literature. Among the 677 data sets, 482 included P concentrations and the N:P ratio.

• At a global scale, the mean leaf-litter N and P and N:P ratio were 10.9 mg g^-1, 0.85 mg g^-1 and 18.3, respectively. Leaf-litter N and P were significantly correlated. When the data was grouped by continents, the highest mean N was found in Africa (19.5 mg g^-1), and the lowest in North America (8.18 mg g^-1). P was significantly smaller in the Asian Islands (Japan and Malaysia, 0.44 mg g^-1) than on the Asian mainland. For the global dataset, leaf-litter N increased linearly with mean annual temperature and annual precipitation and decreased with latitude. Although leaf-litter P showed no significant relationship with temperature, it declined linearly with precipitation and there was a convex quadratic relationship with latitude. For the global dataset and also for different functional groups (e.g. shrubs, evergreen broadleaf, deciduous broadleaf, and conifers) the leaf-litter N:P ratio generally followed a positive linear relationship with temperature and precipitation, and showed a concave quadratic response with latitude.

• The differences in leaf-litter N:P ratio among functional groups and among continents should be taken into account when modeling biogeochemical cycles in different regions as well as on a global scale.